Seasonal variation in metabolism of cultured Pacific oyster, Crassostrea gigas, in Sanggou Bay, China

Rates of respiration and excretion of the Pacific oyster, Crassostrea gigas, were measured seasonally from June 2002 to July 2003 under ambient conditions of food, water temperature, pH, and salinity in Sanggou Bay, an important mariculture coast in north China. The aim of this study is to obtain fundamental data for further establishing an energy budget model and assessing the carrying capacity for cultivation of C. gigas in north China. Oysters were collected monthly or bimonthly from the integrated culture areas of bivalve and kelp in the bay. Oxygen consumption and ammonium and phosphorus excretion rates were measured, and ratios of O/N and NIP were calculated. One-way ANOVA was applied to determine differences among these parameters that act as a function of seasonal variation. All the physiological parameters yielded highly significant variations with season (P<0.01) The rate of respiration varied seasonally, with the highest oxygen consumption rate in July and the lowest rate in January, ranging from 0.07 to 2.13 mg O-2 h(-1) g(-1) dry tissue weight (DW). Maximum and minimum ammonium excretion rates were recorded in August and January, respectively, ranging from 0.51 to 5.40 mu mol NH4-N h(-1) g(-1) DW. Rates of phosphorus excretion varied from 0.11 (in January) to 0.64 (in July) mu mol PO4-P h(-1) g(-1) DW. The O/N and N/P ratios changed from 9.2 (in January) to 59.8 (in July) and from 4.6 (in January) to 10.9 (in August), respectively. For each season, the allometric relationship between the physiological response (e.g., rate of oxygen consumption, ammonium and phosphorus excretion) and DW of the animal was estimated using the formula: Y=a x DWb. (C) 2005 Elsevier B.V. All rights reserved.

Genetic improvement on Chinese shrimp (Fenneropenaeus chinensis): growth and viability performance in F1 hybrids of different populations

Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea (WYP), and the west coast of the Korean Peninsula and coast (WKN). The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea (FKN), the Huang Hai (the Yellow Sea in Chinese) No.1 (HH1), and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length (BL), carapace length (CL), carapace width (CW), height of the second and third abdominal segment (HST), width of the second and third abdominal segment (WST), length of the first abdominal segment (LF), length of the last abdominal segment (LL), live body weight (BW), and survival rate were measured. Different combinations were statistically performed with ANOVA and Duncan's Multiple Range Test. The results show that the survival rate of JK98(a (TM) Euro)xWKN(a (TM),) was the highest, followed by WYP(a (TM) Euro)xWKN(a (TM),), FKN(a (TM) Euro)xWYP(a (TM),), FKN(a (TM) Euro)xHH1(a (TM),) and WYP(a (TM) Euro)xFKN(a (TM),); the body weight of FKN(a (TM) Euro)sxHH1(a (TM),) was the highest, followed by FKN(a (TM) Euro)xWYP(a (TM),), WYP(a (TM) Euro)xWKN(a (TM),), WYP(a (TM) Euro)xFKN(a (TM),) and JK98(a (TM) Euro)xWKN(a (TM),); the total length had the same ranking as the body weight. All growth traits in hybrids JK98(a (TM) Euro)xWKN(a (TM),) were the lowest among all combinations. F1 hybrids had significant difference (P < 0.05) in BL, CL, HST, LL, and BW; and insignificant difference (P > 0.05) in other growth traits and survival rate. The results of Duncan's Multiple Range Test are that BL and CL of JK98(a (TM) Euro)xWKN(a (TM),) were significantly different from the other combinations; HST different from the combination of FKN(a (TM) Euro)xWYP(a (TM),), FKN(a (TM) Euro)xHH1(a (TM),) and WYP(a (TM) Euro)xWKN(a (TM),); and BW different from FKN(a (TM) Euro)xWYP(a (TM),) and FKN(a (TM) Euro)xHH1(a (TM),). As a whole, the results indicate that the FKN(a (TM) Euro)xHH1(a (TM),) was the best combination in all growth traits. Therefore, hybridization can introduce the variation to base populations. The systematic selection program based on additive genetic performance may be more effective than crossbreeding.

改进叠前深度偏移的计算效率＆叠前高分辨率成像

An high-resolution prestack imaging technique of seismic data is developed in this thesis. By using this technique, the reflected coefficients of sheet sands can be gained in order to understand and identify thin oil reservoirs. One-way wave equation based migration methods can more accurately model seismic wave propagation effect such as multi-arrivals and obtain almost correct reflected energy in the presence of complex inhomogeneous media, and therefore, achieve more superiorities in imaging complex structure. So it is a good choice to apply the proposed high-resolution imaging to the presatck depth migration gathers. But one of the main shorting of one-way wave equation based migration methods is the low computational efficiency, thus the improvement on computational efficiency is first carried out. The method to improve the computational efficiency of prestack depth migration is first presented in this thesis, that is frequency-dependent varying-step depth exploration scheme plus a table-driven, one-point wavefield interpolation technology for wave equation based migration methods; The frequency-dependent varying-step depth exploration scheme reduces the computational cost of wavefield depth extrapolation, and the a table-driven, one-point wavefield interpolation technology reconstructs the extrapolated wavefield with an equal, desired vertical step with high computational efficiency. The proposed varying-step depth extrapolation plus one-point interpolation scheme results in 2/3 reduction in computational cost when compared to the equal-step depth extrapolation of wavefield, but gives the almost same imaging. The frequency-dependent varying-step depth exploration scheme is presented in theory by using the optimum split-step Fourier. But the proposed scheme can also be used by other wave equation based migration methods of the frequency domain. The proposed method is demonstrated by using impulse response, 2-D Marmousi dataset, 3-D salt dataset and the 3-D field dataset. A method of high-resolution prestack imaging is presented in the 2nd part of this thesis. The seismic interference method to solve the relative reflected coefficients is presented. The high-resolution imaging is obtained by introducing a sparseness- constrained least-square inversion into the reflected coefficient imaging. Gaussian regularization is first imposed and a smoothed solution is obtained by solving equation derived from the least-square inversion. Then the Cauchy regularization is introducing to the least-square inversion , the sparse solution of relative reflected coefficients can be obtained, that is high-resolution solution. The proposed scheme can be used together with other prestack imaging if the higher resolution is needed in a target zone. The seismic interference method in theory and the solution to sparseness-constrained least-square inversion are presented. The proposed method is demonstrated by synthetic examples and filed data.

地震波模拟：非规则网格离散的数值解法、吸收边界及其实际应用

This dissertation presents a series of irregular-grid based numerical technique for modeling seismic wave propagation in heterogeneous media. The study involves the generation of the irregular numerical mesh corresponding to the irregular grid scheme, the discretized version of motion equations under the unstructured mesh, and irregular-grid absorbing boundary conditions. The resulting numerical technique has been used in generating the synthetic data sets on the realistic complex geologic models that can examine the migration schemes. The motion equation discretization and modeling are based on Grid Method. The key idea is to use the integral equilibrium principle to replace the operator at each grid in Finite Difference scheme and variational formulation in Finite Element Method. The irregular grids of complex geologic model is generated by the Paving Method, which allow varying grid spacing according to meshing constraints. The grids have great quality at domain boundaries and contain equal quantities of nodes at interfaces, which avoids the interpolation of parameters and variables. The irregular grid absorbing boundary conditions is developed by extending the Perfectly Matched Layer method to the rotated local coordinates. The splitted PML equations of the first-order system is derived by using integral equilibrium principle. The proposed scheme can build PML boundary of arbitrary geometry in the computational domain, avoiding the special treatment at corners in a standard PML method and saving considerable memory and computation cost. The numerical implementation demonstrates the desired qualities of irregular grid based modeling technique. In particular, (1) smaller memory requirements and computational time are needed by changing the grid spacing according to local velocity; (2) Arbitrary surfaces and interface topographies are described accurately, thus removing the artificial reflection resulting from the stair approximation of the curved or dipping interfaces; (3) computational domain is significantly reduced by flexibly building the curved artificial boundaries using the irregular-grid absorbing boundary conditions. The proposed irregular grid approach is apply to reverse time migration as the extrapolation algorithm. It can discretize the smoothed velocity model by irregular grid of variable scale, which contributes to reduce the computation cost. The topography. It can also handle data set of arbitrary topography and no field correction is needed.

军队医学科技人员身心健康与影响因素的研究

To study the relationship between mental-physical health and coping behavior,job stress and job motivation in medical laboratory scientists and technicians. A cross-section survey was conducted,using the anxiety rating scale(SAS), depression rating scale(SDS), coping behavior rating scale,self-rating subhealth scale,self-rating stress scale,and self-rating job motivation scale among 289 medical laboratory scientists and technicians with analysis of ANOVA and Regression. The study was carried out in three steps:step1 is to analyze the general situation of the mental-physical health.Step 2 is to analyze the features of the main influencial facotors.Step 3 is to study the influence of the relative factors on mental-physical health.The following are the results: 1.The anxiety and depression scores of the medical researchers and technicians were 30±6 and 37±8 respectively,both significantly lower than those of the national norm（34±6 and 42±11 respectively,both P<0.01）,which are of significant difference. The depression score of the associate chief technician was 42±7, significantly higher than those of the medical researchers and technicians with any other professional titles (all P<0.05）, and the anxiety score of the associate chief technicians was 32±7, significantly higher than that of the research fellows（28±4, P<0.05），with no significant difference to the score of the medical researchers and technicians with other professional titles. The depression score,anxiety score and the subhealth score of the age group of 36～49 were 39±9,31±7 and 32±9 respectively, both higher than that of the age group of 20～35 （36±8,29±6 and 29±7 respectively,both P<0.05）,while there is much diference among other age groups. And the subhealth status has nothing to do with marital status,education background and professional titles. 2.The coping behaviors,job stress and motivation of the military medical laboratory scientists and technicians. 1）Coping behaviors:The seeking help score of the associate chief technicians was 2.8±0.5,not significantly different from that of the associate research fellows（2.8±0.5）,but significantly lower than those of the medical researchers and technicians with other professional titles(all P<0.01),and whose self-blame score was higher than that of the research fellows,which is of significant difference.The self-blame score and the imagination score of the associate research fellows were 2.0±0.5 and 2.4±0.5 respectively, significantly higher than that of the research fellows(1.6±0.4, 2.1±0.4,both P<0.01). The seeking help score of the females was 3.1±0.5, significantly higher than that of the males(2.9±0.5, both P<0.01),and the solving problem score was 3.4±0.6,significantly lower than the male(3.6±0.7, both P<0.01).There is no any significant difference in coping behaviors among researchers and technicians of different marital status,education background and age groups. 2)Job stress: The score of job stress of the age group of 35~49 and 50~60 were 23±8 and 25±6 respectively,significantly higher than that of the 20~35(21±7,both P<0.05). There is no any significant difference in job stress among researchers and technicians of different marital status,gender,professional titles and education background. 3)The score of meeting personal desire for reputation and interests of the males was 19.6±5.4，significantly higher than that of the females(18.4±5.0, both P<0.05), while there is no significant difference in job motivation among researchers and technicians of different titles,education,age and marital status. 3.The relationship of the mental-physical health of the military medical laboratory scientists and technicians with their coping behaviors,job stress and motivations 1) Coping behaviors:Regression analysis showed that, the best predictors of subhealth were anxiety,depression and escaping (β=-0.40,β=0.23, β=0.14, both P<0.01).the best predictors of anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only of anxiety and of significant difference. 2)job stress : Regression analysis demonstrated that anxiety,depression,job stress 2 and job stress 4 are the best predictor for subhealth;job stress 12 is the best retro-predictor for depression; job stress 3 and 8 are the best predictor for depression;and job stress 2 and 9 are the best predictor for anxiety ,which are of significant difference. 3)Motivation:Regression analysis demonstrated that depression is the best predictor for subhealth while motivation itself doesn't predict subhealth;with respect to the specific contents of motivation,"probing unknown rules and making contributions to the human society "is the best retro-predictor for depression and has nothing to do with anxiety prediction. 4) The combined influences of coping behaviors,job stress and motivations: Regression analysis showed that, the best predictors for subhealth were anxiety,depression and job stress(β=0.41,β=0.24, β=0.19, both P<0.01).the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only for anxiety and of significant difference. CONCLUSIONS: Regression analysis showed that the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors, the best predictors for subhealth were anxiety,depression and job stress.Coping behaviors, job stress and motivations have significant influences on the mental-physical health of the military medical researchers and and technicians. Among them,coping behavior is the most important factor while job stress and motivation follow. Seeking help more often,less self-blame ,imagination and job stress could help release the anxiety, depression and improve the subhealth of the medical researchers and technicians. The findings of this study indicate we should address the physical and mental health of the military laboratory researchers and technicians.

领导行为的复杂性、角色结构及其有效性研究

As the social and organizational environment become more and more complex, the topic of leadership complexity is gaining more and more attention. So far, some critical issues in this field need further exploration, such as clarifying the theoretical framework, developing and validating the measurments and exploring the mechanism of the its effectiveness. Using BEI(Behavioral Event Interview), content analysis and EFA/CFA, ANOVA, regression analysis and other qualitative/quantitative methods, this research explored the leadership structure of Chinese enterprise managers, developed a new leadership questionnaire, investigated the differences of the leadership roles among various managerial areas and on different hirachical levels, and examined the impacts of the leadership roles and leadership complexity on different indicators of leadership effectiveness in various organizational contexts. 1,020 managers were surveyed. The followings are the main findings： First，the structure of leadership behaviors of Chinese enterprise managers included ethical model, authoritarian, producer, director, monitor, mentor, strategist, enterpriser, among which ethical model and authoritarian are the new findings in Chinese cultural context. Ethical model was characterized by presenting honesty, setting an example to others, being just and diligent. Authoritarian was characterized by showing power and arbitrariness. In addition, mentor, strategist and enterpriser incarnated some cultural features of present China. The new developed leadership questionnaire’s reliability and validity reached the criterion of standardized measurement. Second, there were significant differences of frequency of leadership behaviors among the managers at different managerial postions and hirachical levels, while the impacts of different leadership roles on different leadership effectiveness indicators were also singnificantly different. Ethical model had positive impacts on the whole performance and three indicators across task and context performance, and authoritarian’s impacts on the whole performance and department performance were negatively significant. Third, the impact of leadership complexity on the whole leadership effectiveness was positively significant, while the moderating effects of organization level and position function was not significant.

三种权重赋值方法下项目的权重决策

It is a weighting process to justify the importance of different items. This paper is about how the estimator distributes profiling the weights to different items. This paper is about using design of psychological experiment to figure out the profiles of the weights of different ranked items in three weighting methods, and in the experiment we use five topics as experimental materials. At the same time, we controlled the factors such as the familiarity about the topic and the number of items. Then we use the curve estimation to figure out the exact profiles and use ANOVA to test the topic effects. Curve estimation result shows that there is difference between the profiles of the weights of different ranking items in three weighting methods. To PA, the weighting profile is logarithmic curving style, and to DR, the weighting profile is linear style. ANOVA result shows that there are topic effects to different weighting profiles. But to go ahead, when we use point allocation (PA) to the more important items, the topics seems to have little effects. The methods have relatively more effect than the topics. The result also indicates that to PA methods, there is no significant difference the weight profiles between the fix-sum and the open-sum. This result has a contribution to the basic research to the management science and social science.

慢性海洛因成瘾者的冲动性和行为抑制缺陷脑机制

In recent years, the deficit of inhibition has become an important reason for explaining addiction. Response inhibition resembles the compulsive drug seeking behavior and it is the basement of addiction inhibition deficits. However, there were no enough evidence for the relationship between addiction and response inhibition deficits and the results of the neuro mechanisms studies remains unclear. Few studies has focused on the exploring the heroin users. Among those paradigms for study response inhibition deficits, stop signal is a very suitable model for the representation of compulsive drug seeking, but only a few researches has worked on this paradigm. In this study, we selected about 100 heroin abusers and had behaviour and neuro imaging scannings for investigating the response inhibition deficits. The behaviour researches found: first, the chronic heroin users had longer reaction time than control group and this reaction time were not affected by stop signals in heroin users. Second, heroin users had less waiting time than control group and they were more impulsive but less flexibility. Their erro monitoring and flexibale adjustment ability decreased. Third, the SSRT of heroin users was significantly longer than control group. These results suggested that the inhibition of heroin users were impaired. Further investigation showed that the SSRT of heroin users had positive correlation of four factor scores of ASI and the macro correlation coefficient was factor three of drug use. This correlation suggested that drug use was the main reason of inhibition deficits. fMRI results mainly focused on the ANOVA analysis for group difference. First, there was no intensity difference in M1 and SMA brain areas between the two groups. Second, heroin users had less activation in right dorsalateral prefrontal cortex, right inferior prefrontal cortex and anterior cingulated cortex, while in bilateral striatum and amygdala, heroin users had more activation than control group. The right prefrontal cortex was indentified as the main inhibition brain area. The anterior cingulated cortex has relationship with erro monitoring and amygdale was an important brain area for impulsivity and emotion control. The network of these brain areas was envovled in impulsivity and inhibition and it was suggested the mainly damaged network for heroin users’ disinhibition. We also investigated the gray matter changes of heroin users and found that chonic heroin use made their gray matter density decreased in prefrontal cortex (including bilateral dorsalateral prefrontal cortex, obital frontal cortex, inferior prefrontal cortex) and anterior cingulated cortex. The gray matter density in these brain regions had negative correlation with drug use duration. In conclusion, we indentified the disinhibition of heroin users and its neuro mechanism. Their compulsivity brain areas had more activation than control group and their inhibition brain areas had less activation than normal control. On the other side, the biological mechanism of this activation changes was the gray matter density decrease in these brain areas.

应急疏散语音告警信号设计参数的研究

Voice alarm plays an important role in emergency evacuation of public place, because it can provide information and instruct evacuation. This paper studied the optimization of acoustic and semantic parameters of voice alarms in emergency evacuation, so that alarm design can improve the evacuation performance. Both method of magnitude estimation and scale were implemented to investigate participants' perceived urgency of the alarms with different parameters. The results indicated that, participants evaluated the alarms with faster speech rate, with greater signal to noise ratio (SNR) and under louder noises more urgent. There was an interaction between noise level and content of voice alarm. Signals with speech rate below 4 characters / second were evaluated as non urgent at all. Intelligibility of the voice alarm was investigated by evaluating the key pointed recognition performance. The results showed that, speech rate’s effect was a marginal significance, and 7 characters / second has the highest intelligibility. It might because that the faster the signal spoken, the more attention was paid. Gender of speaker and SNR did not have a significant effect on the signals’ intelligibility. This paper also investigated impact of voice alarms' content on human behavior in emergency evacuation in a 3-D virtual reality environment. In condition of "telling the occupants what had happened and what to do", the number of participants who succeeded in evacuation was the largest. Further study, in which similar numbers of participants evacuate successfully in three conditions, indicated that the reaction time and evacuation time was the shortest in the aforesaid condition. Although one-way ANOVA shows that the difference was not significant, the results still provided some reference to the alarm design. In sum, parameters of voice alarm in emergency evacuation should be chosen to meet needs from both perceived urgency and intelligibility. Contents of the alarms should include "what had happened and what to do", and should vary according to noise levels in different public places.

物体朝向对场景内在参照系建立的影响

Six experiments tested how headings of objects in scenes influenced the construction for the intrinsic frame of reference under different structure and viewpoint amount conditions. In Experiment 1 and 2, participants stood at 0 degree and learned an asymmetrical scene and a symmetrical scene that were composed by balls with no apparent headings separately. In Experiment 3, 4, 5 and 6, toys with apparent headings were used and they all faced the 315 degree of the scene. In Experiment 3 and 4, participants stood at 0 degree and learned an asymmetrical scene and a symmetrical scene that were composed by toys separately. In Experiment 5 and 6, participants stood at 0 and 315 degree and learned an asymmetrical scene and a symmetrical scene that were composed by toys separately. After learning, participants needed to finish triplet recognition tasks in all the experiments. The dependent measures were response latency and accuracy. The correct response latencies to the targets were analyzed by ANOVA. Accuracy was used to filter data and analyzed in an ANOVA in some experiments as a reference. Results indicate that headings of objects in scenes influence the pattern for intrinsic frame of reference. The structure of scene affects the acting mechanism of heading, but the amount of viewpoints does not have this effect. If the objects in scenes have no apparent headings, there will be viewpoint dependent effect and the advantage of symmetry axis as intrinsic axis in triplet recognition tasks. If the objects in scenes have apparent headings, people’s spatial memory pattern will be affected by objects’ headings. If the heading of objects (315 degree) is not parallel to the viewpoint (0 degree) in an asymmetrical scene, people will be inclined to represent the scene from the heading of objects but not from the viewpoint. As a result, the viewpoint dependent effect will disappear, and there is significant advantage for the triplets presented from heading of objects. If the heading of objects is not parallel to the symmetry axis in a symmetrical scene, people will represent the scene not only according to the symmetry axis as intrinsic axis, but also according to the heading of objects. As a result, the significant advantage for symmetry axis as intrinsic axis in triplet recognition tasks will disappear but there will be still a tendency. By contrast, the effect for the headings of objects is more significant in asymmetrical scenes than that in symmetrical scenes.

国营企业中激励机制的个案研究

This research objective was to investigate the working motivation in a large state-owned enterprise, Luoyang White Horse Company Group in Henan Province. Some standard methods, such as in-depth interview, questionnaire were employed. This research is divided into two parts: 1. The first is to investigate the factor structure of working motivation, by the way of survey questionnaire. 2. The second is to do a case study to the White Horse Company, by using survey questionnaire and interview methods. The results shows that: 1. Eight factors are extracted by the Exploring Factor Analysis. These factors include: material reward factor, leader factor, fairness factor, goal factor, mental reward factor, development factor, job factor, participation factor. The overall explanation is 56.0%. 2. By the One-Way ANOVA and Multiple Comparison, it is found that: working age, age, sex, education background, income and assignment all have a notable effect on some of the eight factors. 3. By the case study to the White Horse Company, it is found that there still is no a perfect motivating mechanism in the White Horse Company and the disproportion of reward and punishment has a disadvantageous effect on the worker's productivity.

Structural Saliency: The Detection of Globally Salient Structures Using a Locally Connected Network

Certain salient structures in images attract our immediate attention without requiring a systematic scan. We present a method for computing saliency by a simple iterative scheme, using a uniform network of locally connected processing elements. The network uses an optimization approach to produce a "saliency map," a representation of the image emphasizing salient locations. The main properties of the network are: (i) the computations are simple and local, (ii) globally salient structures emerge with a small number of iterations, and (iii) as a by-product of the computations, contours are smoothed and gaps are filled in.

Time-Frequency Representations for Speech Signals

This work addresses two related questions. The first question is what joint time-frequency energy representations are most appropriate for auditory signals, in particular, for speech signals in sonorant regions. The quadratic transforms of the signal are examined, a large class that includes, for example, the spectrograms and the Wigner distribution. Quasi-stationarity is not assumed, since this would neglect dynamic regions. A set of desired properties is proposed for the representation: (1) shift-invariance, (2) positivity, (3) superposition, (4) locality, and (5) smoothness. Several relations among these properties are proved: shift-invariance and positivity imply the transform is a superposition of spectrograms; positivity and superposition are equivalent conditions when the transform is real; positivity limits the simultaneous time and frequency resolution (locality) possible for the transform, defining an uncertainty relation for joint time-frequency energy representations; and locality and smoothness tradeoff by the 2-D generalization of the classical uncertainty relation. The transform that best meets these criteria is derived, which consists of two-dimensionally smoothed Wigner distributions with (possibly oriented) 2-D guassian kernels. These transforms are then related to time-frequency filtering, a method for estimating the time-varying 'transfer function' of the vocal tract, which is somewhat analogous to ceptstral filtering generalized to the time-varying case. Natural speech examples are provided. The second question addressed is how to obtain a rich, symbolic description of the phonetically relevant features in these time-frequency energy surfaces, the so-called schematic spectrogram. Time-frequency ridges, the 2-D analog of spectral peaks, are one feature that is proposed. If non-oriented kernels are used for the energy representation, then the ridge tops can be identified, with zero-crossings in the inner product of the gradient vector and the direction of greatest downward curvature. If oriented kernels are used, the method can be generalized to give better orientation selectivity (e.g., at intersecting ridges) at the cost of poorer time-frequency locality. Many speech examples are given showing the performance for some traditionally difficult cases: semi-vowels and glides, nasalized vowels, consonant-vowel transitions, female speech, and imperfect transmission channels.

Local Rotational Symmetries

This thesis describes a new representation for two-dimensional round regions called Local Rotational Symmetries. Local Rotational Symmetries are intended as a companion to Brady's Smoothed Local Symmetry Representation for elongated shapes. An algorithm for computing Local Rotational Symmetry representations at multiple scales of resolution has been implemented and results of this implementation are presented. These results suggest that Local Rotational Symmetries provide a more robustly computable and perceptually accurate description of round regions than previous proposed representations. In the course of developing this representation, it has been necessary to modify the way both Smoothed Local Symmetries and Local Rotational Symmetries are computed. First, grey-scale image smoothing proves to be better than boundary smoothing for creating representations at multiple scales of resolution, because it is more robust and it allows qualitative changes in representations between scales. Secondly, it is proposed that shape representations at different scales of resolution be explicitly related, so that information can be passed between scales and computation at each scale can be kept local. Such a model for multi-scale computation is desirable both to allow efficient computation and to accurately model human perceptions.

Determination of heat capacities and thermodynamic properties of 2-(chloromethylthio)benzothiazole by an adiabatic calorimeter

The molar heat capacities of 2-(chloromethylthio)benzothiazole (molecular formula C8H6ClNS2, CA registry no. 28908-00-1) were measured with an adiabatic calorimeter in the temperature range between (80 and 350) K. The construction and procedures of the calorimeter were described in detail. The performance of the calorimetric apparatus was evaluated by heat capacity measurements on alpha-Al2O3. The deviation of experiment heat capacities from the corresponding smoothed values lies within 0.3%, whereas the uncertainty is within +/-0.5%, compared with that of the recommended reference data over the whole experimental temperature range. A fusion transition was found from the C-p-T curve of 2-(chloromethylthio)benzothiazole. The melting temperature and the molar enthalpy and entropy of fusion of the compound were determined to be T-m = (315.11 +/- 0.04) K, Delta(fus)H(m) = (17.02 +/- 0.03) kJ(.)mol(-1), and Delta(fus)S(m) = (54.04 +/- 0.05) J(.)mol(-1.)K(-1), respectively. The thermodynamic functions (H-T - H-298.15) and (S-T - S-298.15) were also derived from the heat capacity data. The molar fraction purity of the 2-(chloromethylthio)benzothiazole sample used in the present calorimetric study was determined to be 99.21 by fraction melting.