• Computers and Concrete
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• 제19권1호
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• pp.99-110
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• 2017

In this paper, the effect of normal load on the failure mechanism of echelon joint has been studied using PFC2D. In the first step, calibration of PFC was undertaken with respect to the data obtained from experimental laboratory tests. Then, six different models consisting various echelon joint were prepared and tested under two low and high normal loads. Furthermore, validation of the simulated models were cross checked with the results of direct shear tests performed on non-persistent jointed physical models. The simulations demonstrated that failure patterns were mostly influenced by normal loading, while the shear strength was linked to failure mechanism. When ligament angle is less than $90^{\circ}$, the stable crack growth length is increased by increasing the normal loading. In this condition, fish eyes failure pattern occur in rock bridge. With higher ligament angles, the rock bridge was broken under high normal loading. Applying higher normal loading increases the number of fracture sets while dilation angle and mean orientations of fracture sets with respect to ligament direction will be decreased.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.631-634
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• 2004

In this paper, the Bayesian recurrent neural network (BRNN) is proposed to predict time series data. Among the various traditional prediction methodologies, a neural network method is considered to be more effective in case of non-linear and non-stationary time series data. A neural network predictor requests proper learning strategy to adjust the network weights, and one need to prepare for non-linear and non-stationary evolution of network weights. The Bayesian neural network in this paper estimates not the single set of weights but the probability distributions of weights. In other words, we sets the weight vector as a state vector of state space method, and estimates its probability distributions in accordance with the Bayesian inference. This approach makes it possible to obtain more exact estimation of the weights. Moreover, in the aspect of network architecture, it is known that the recurrent feedback structure is superior to the feedforward structure for the problem of time series prediction. Therefore, the recurrent network with Bayesian inference, what we call BRNN, is expected to show higher performance than the normal neural network. To verify the performance of the proposed method, the time series data are numerically generated and a neural network predictor is applied on it. As a result, BRNN is proved to show better prediction result than common feedforward Bayesian neural network.

• 대한지역사회영양학회지
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• 제4권4호
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• pp.554-560
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• 1999

This study was conducted to find adolescent females perception of body image. The survey was carried out by self-questionnaires with 463 female school and college students in Daegu. Analysis of data was done using t-test, and ANOVA with the SAS computer program. The average height, weight and BMI of the subjects were 161.2cm, 53.4kg and 20.51kg/$m^2$. It appeared that 33.3% of the subjects were off the normal range of body weight ; in particular 25.1% of the subjects were under weight. While the subjects’perception of their own current body image was not distorted, they were dissatisfied with their body image because they wanted a very thin figure. Subjects were divided into 3 groups -underweight, normal weight, overweight-according to their current body size. Their perceptions of ideal and desired figures differed significantly between the groups, but they thought a thinner figure than normal body image as ideal and desired body image even in overweight group. As a result, dissatisfaction of body image in the overweight group was significantly larger than the normal-weight group, and that of the normal-weight group was larger than the underweight group. Percentages of weight control attempt were 51.7% and 64.7% in the normal weight and underweight subjects, respectively. Subjects were divided into 2 groups according to their weight control experience : those who have attempted, and who have not attempted. Weight control attemptees had a higher level of dissatisfaction with their body image than non-attemptees, both because weight control attemptees were fatter, and they perceived a thinner figure as an ideal and as a desired body image thin non-attemptees. From the results of this study, we confirmed that one of reasons of excessive weight control behavior among adolescent females was distorted perception about ideal body image.

• 한국빅데이터학회지
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• 제4권1호
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• pp.11-27
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• 2019

컨테이너터미널 경영환경이 악화됨에 따라 컨테이너터미널의 수익률은 점차 감소하고 있다. 컨테이너터미널 운영자는 전반적인 컨테이너터미널의 문제점을 분석하고 개선함으로써 컨테이너터미널의 글로벌 경쟁력을 높이고자 한다. 이를 위해 컨테이너터미널은 운영 중 생성되는 데이터를 실시간으로 수집 및 저장하고 있으며, 운영자는 저장된 데이터를 활용하여 운영 문제를 분석하고자 많은 노력을 기울여왔다. 본 연구에서는 컨테이너터미널 운영 프로세스의 특성을 분석하고 컨테이너터미널 운영을 효과적으로 분석하기 위한 컨테이너 프로세스 및 CKO(container keeping object) 프로세스를 제안한다. 또한 TOS(terminal operating system)에 저장된 데이터로부터 본 연구에서 제안된 프로세스를 생성하기 위한 이벤트 로그를 정의한다. 제안된 프로세스를 활용하여 비정상적인 프로세스를 만드는 불완전한 이벤트 로그가 어떻게 효과적으로 정제되는지 설명한다. 이벤트 로그를 쉽고 빠르게 수정하기 위한 프레임워크를 제안하였으며, 이를 검증하기 위해 python2.7을 이용하여 해당 프레임워크를 구현하였다. 또한 실제 컨테이너터미널에서 수집된 데이터를 입력 데이터로 사용하여 제안된 프레임워크의 타당성을 검증하였다. 그 결과, 이벤트 로그 정제를 통해 컨테이너터미널의 비정상적인 프로세스가 크게 개선되었음을 확인할 수 있었다.

• 대한산업공학회지
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• 제28권2호
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• pp.147-161
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• 2002

In novelty detection, one attempts to discriminate abnormal patterns from normal ones. Novelty detection is quite difficult since, unlike usual two class classification problems, only normal patterns are available for training. Auto-Associative Multi-Layer Perceptron (AAMLP) has been shown to provide a good performance based upon the property that novel patterns usually have larger auto-associative errors. In this paper, we give a mathematical analysis of 2-layer AAMLP's output characteristics and empirical results of 2-layer and 4-layer AAMLPs. Various activation functions such as linear, saturated linear and sigmoid are compared. The 2-layer AAMLPs cannot identify non-linear boundaries while the 4-layer ones can. When the data distribution is multi-modal, then an ensemble of AAMLPs, each of which is trained with pre-clustered data is required. This paper contributes to understanding of AAMLP networks and leads to practical recommendations regarding its use.

• 유통과학연구
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• 제20권9호
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• pp.83-95
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• 2022

Purpose: This study aims to explore an ability to time market-wide investor sentiment of mutual fund managers in an emerging market. Research design, data, and methodology: Based on data of Thai mutual fund market over the period of 2000-2019, our sample includes 283 equity funds, consisting of 204 bank-related funds and 79 nonbank-related funds. We perform our regression analyses at the aggregate and portfolio levels. Results: Under the non-normal distribution of return, we find different behaviors between the best- and worst-performing funds in an ability to time market-wide investor sentiment in Thailand, which is dissimilar to the findings in the U.S. Bottom fund managers act as sentiment hedgers, who decrease (increase) an exposure of investment portfolios when the investor sentiment is high (low). Oppositely, top fund managers are likely to chase investor sentiment. Conclusion: We find that only the worst-performing fund managers, especially for bank-related funds are able to time the market-wide investor sentiment. An advantage of gaining information from their bank's clients is a key success. A competition in the mutual fund industry, an ability to predict fundamentals, and financial literacy are possible reasons to explain the main findings found in this study.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제28권2호
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• pp.17-29
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• 2022

Purpose: In terms of efficiency and safety, this study attempted to organize data on the operation methods and architectural planning of infectious diseases hospitals. Methods: The results obtained through on-site and interview surveys with hospital officials and medical staffs at four infectious diseases hospitals under construction were summarized based on those original business plans and facility guidelines. Results: First, the operational methods to secure safety and operational efficiency were summarized for each department which are major hospital functions of infectious disease hospitals. Second, as the architectural planning, the characteristics of space and circulation of each department are summarized. For safety of medical staff, negative pressure and non-negative pressure zone have to completely separated. In addition medical staff wears PPE and enters the negative pressure zone and returns in the order of admiral, shower, and gowning in the PPE undressing room after patient treatment. In case of operational efficiency, flexible operation is required in normal and crisis situations. For example, it is important for The Ward to gradually switch to negative pressure beds in times of crisis from normal situation and the outpatient department considers the composition of negative pressure and non-negative pressure outpatient spaces that can operate in parallel even in crisis situations. Implications: Infectious disease hospitals require flexible operation and appropriate facilities for normal and crisis situations.

• Nutrition Research and Practice
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• 제9권4호
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• pp.425-432
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• 2015

BACKGROUND/OBJECTIVES: Food insecurity has been suggested as being negatively associated with healthy behaviors and health status. This study was performed to identify the associations between food insecurity and healthy behaviors among Korean adults. SUBJECTS/METHODS: The data used were the 2011 Community Health Survey, cross-sectional representative samples of 253 communities in Korea. Food insecurity was defined as when participants reported that their family sometimes or often did not get enough food to eat in the past year. Healthy behaviors were considered as non-smoking, non-high risk drinking, participation in physical activities, eating a regular breakfast, and maintaining a normal weight. Multiple logistic regression and multinomial logistic regression analyses were used to identify the association between food insecurity and healthy behaviors. RESULTS: The prevalence of food insecurity was 4.4% (men 3.9%, women 4.9%). Men with food insecurity had lower odds ratios (ORs) for non-smoking, 0.75 (95% CI: 0.68-0.82), participation in physical activities, 0.82 (95% CI: 0.76-0.90), and eating a regular breakfast, 0.66 (95% CI: 0.59-0.74), whereas they had a higher OR for maintaining a normal weight, 1.19 (95% CI: 1.09-1.30), than men with food security. Women with food insecurity had lower ORs for non-smoking, 0.77 (95% CI: 0.66-0.89), and eating a regular breakfast, 0.79 (95% CI: 0.72-0.88). For men, ORs for obesity were 0.78 (95% CI: 0.70-0.87) for overweight and 0.56 (95% CI: 0.39-0.82) for mild obesity. For women, the OR for moderate obesity was 2.04 (95% CI: 1.14-3.63) as compared with normal weight. CONCLUSIONS: Food insecurity has a different impact on healthy behaviors. Provision of coping strategies for food insecurity might be critical to improve healthy behaviors among the population.

• Clinical and Experimental Reproductive Medicine
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• 제48권1호
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• pp.61-68
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• 2021

Objective: This study was conducted to investigate the relationship of semen parameters in samples used for intracytoplasmic sperm injection (ICSI) with fertilization and pregnancy rates in infertile couples. Methods: In this prospective study of Infertile couples with male factor infertility that had undergone ICSI, fractions of the same semen samples obtained for microinjection (to ensure the best predictability) were evaluated to determine the semen parameters and sperm DNA fragmentation index (DFI) on the day of oocyte recovery. Results: In total, 120 couples completed the study and were subdivided into fertilized (n=87) and non-fertilized couples (n=33). The fertilized couples were further classified into pregnant (n=48) and non-pregnant (n=39) couples. Compared to non-fertilized and non-pregnant couples, fertilized and pregnant couples showed statistically significantly higher sperm viability and percentage of normal sperm morphology, as well as significantly lower sperm DFI values. A receiver operating characteristic curve analysis of data from the 120 ICSI cycles showed that sperm viability, normal sperm morphology percentages, and sperm DFI were significant prognostic indicators of fertilization at cutoff values of 40%, 7%, and 46%, respectively. A sperm DFI of 46% showed sensitivity and specificity of 95% and 90%, respectively, for predicting fertilization, and no clinical pregnancies occurred in couples with a sperm DFI above 46%. Conclusion: Semen parameters from the ICSI day sample, especially sperm viability, normal morphology, and DFI, had an impact on fertilization and pregnancy outcomes in ICSI cycles.

• 말소리와 음성과학
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• 제6권3호
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• pp.49-56
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• 2014

This research compared the features of respiration and phonation between practical musicology students and general male students, according to their smoking status. Participants of this research are 15 practical musicology male students attending ${\bigcirc}{\bigcirc}$ university and 16 general ${\bigcirc}{\bigcirc}{\bigcirc}$ university students. The participants, both non-smokers and smokers with 5-years of smoking history have no history of voice disease in any case and have normal cognitive functions. The results indicated that, first, there is not a notable difference in the respiratory activity status(FVC, FEV1, FEV1/FVC), regardless of major and smoking status. In MPT, even though there is no significant difference in accordance with their majors, considering smoking status, the smoker group was shorter than non-smoker group significant difference statistically (p<.01). Second, the divisions of participants' major did not show significant difference in Fo, jitter, shimmer, and NHR in the vowel prolongation task. However, the smoker group showed a significantly higher degree of jitter and shimmer than the non-smoker group (p<.05) as Fo and NHR shows no difference. In the case of VRP, maximum frequency and frequency range of the practical group are significantly higher than normal group statistically (p<.001). Moreover, although the difference of the minimum frequency shown at the statistic is not significant, practical group showed a higher tendency of frequency than normal group (p=.051). In conclusion, even though there is no difference in respiratory activity between the smoker group and non-smoker group, the MPT of the smoker group is shorter than that of non-smoker group. In addition, the smoker group showed a higher degree of jitter and shimmer than the non-smoker group. MPT is related to the valve action of vocal fold that passes through the glottis. Thus, it is interpreted that the smoker group has a lower quality of voice and valve action of the vocal fold. Also, the practical group has a higher degree of maximum frequency and frequency range than the normal group. This research can function as basic data for vocal characteristics for the majors in relation to the voice-specializing.