• Structural Engineering and Mechanics
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• v.85 no.4
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• pp.469-484
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• 2023

A deep recursive bidirectional Cuda Deep Neural Network Long Short Term Memory (Bi-CuDNNLSTM) layer is recruited in this paper to predict the entire force time histories, and the corresponding hysteresis and backbone curves of reinforced concrete (RC) bridge piers using experimental fast and slow cyclic tests. The proposed stacked Bi-CuDNNLSTM layers involve multiple uncertain input variables, including horizontal actuator displacements, vertical actuators axial loads, the effective height of the bridge pier, the moment of inertia, and mass. The functional application programming interface in the Keras Python library is utilized to develop a deep learning model considering all the above various input attributes. To have a robust and reliable prediction, the dataset for both the fast and slow cyclic tests is split into three mutually exclusive subsets of training, validation, and testing (unseen). The whole datasets include 17 RC bridge piers tested experimentally ten for fast and seven for slow cyclic tests. The results bring to light that the mean absolute error, as a loss function, is monotonically decreased to zero for both the training and validation datasets after 5000 epochs, and a high level of correlation is observed between the predicted and the experimentally measured values of the force time histories for all the datasets, more than 90%. It can be concluded that the maximum mean of the normalized error, obtained through Box-Whisker plot and Gaussian distribution of normalized error, associated with unseen data is about 10% and 3% for the fast and slow cyclic tests, respectively. In recapitulation, it brings to an end that the stacked Bi-CuDNNLSTM layer implemented in this study has a myriad of benefits in reducing the time and experimental costs for conducting new fast and slow cyclic tests in the future and results in a fast and accurate insight into hysteretic behavior of bridge piers.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.456-477
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• 2024

With information technology's rapid development, the Internet faces serious security problems. Studies have shown that malware has become a primary means of attacking the Internet. Therefore, adversarial samples have become a vital breakthrough point for studying malware. By studying adversarial samples, we can gain insights into the behavior and characteristics of malware, evaluate the performance of existing detectors in the face of deceptive samples, and help to discover vulnerabilities and improve detection methods for better performance. However, existing adversarial sample generation methods still need help regarding escape effectiveness and mobility. For instance, researchers have attempted to incorporate perturbation methods like Fast Gradient Sign Method (FGSM), Projected Gradient Descent (PGD), and others into adversarial samples to obfuscate detectors. However, these methods are only effective in specific environments and yield limited evasion effectiveness. To solve the above problems, this paper proposes a malware adversarial sample generation method (PixGAN) based on the pixel attention mechanism, which aims to improve adversarial samples' escape effect and mobility. The method transforms malware into grey-scale images and introduces the pixel attention mechanism in the Deep Convolution Generative Adversarial Networks (DCGAN) model to weigh the critical pixels in the grey-scale map, which improves the modeling ability of the generator and discriminator, thus enhancing the escape effect and mobility of the adversarial samples. The escape rate (ASR) is used as an evaluation index of the quality of the adversarial samples. The experimental results show that the adversarial samples generated by PixGAN achieve escape rates of 97%, 94%, 35%, 39%, and 43% on the Random Forest (RF), Support Vector Machine (SVM), Convolutional Neural Network (CNN), Convolutional Neural Network and Recurrent Neural Network (CNN_RNN), and Convolutional Neural Network and Long Short Term Memory (CNN_LSTM) algorithmic detectors, respectively.

• The Korean Journal of Financial Management
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• v.23 no.2
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• pp.109-141
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• 2006

The central factor in the pecking order theory of financial structure is the asymmetric distribution of information between managers and less-informed outside investors. Myers and Majluf (1984) show that this asymmetry leads managers to prefer internal funds to external funds. Funds are raised through equity issues only after the capacity to issue debt has been exhausted. In contrast, according to static tradeoff theory, an optimum financial structure exists by the tradeoff between tax saving by debt and bankruptcy costs. This study examines the recent changes of Korean firms' financial structure and financing behavior and the determinants of financial structure. The sample of firms comes from the period of $1996{\sim}2004$, and the number of firms is 32,003. The major findings are as follows. First, in contrast with previous studies using US firms as sample, Korean firms have been using debt financing as their major financing instrument. Especially, the firms in the fund deficit situation relies much more on $long{\sim}term$ and $short{\sim}term$ debts rather than on equity issues. Second, as is the case with previous studies using US firms sample indicates, the financing deficit variable can not explain perfectly the net debt issue. However, compared with net equity issue variable, net debt issue variable is more closely related to the financing deficit variable. Third, when financing deficit variable is added to the current list of explanatory variables of financial structure determinants model, it has a significant and positive explanatory power. In addition, the coefficients of determinants are much improved. Thus, it is concluded that although pecking order theory is not perfect, it appears to be more useful compared to static tradeoff theory, at least in explaining the recent financing behavior of Korean manufacturing firms.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.192-201
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• 1999

This study was aimed to introduce the measurement of $CO_2$ concentration and leaf area index in the phytotron for predicting the effect of CO.E, light and leaf area index on the instantaneous photosynthetic rate of sweet pepper with the existing ASKAM model. Measurements were made in 2 semi-closed phytotron compartments in which three different $CO_2$ concentrations were applied at random. Plants were grown on containers with circulating nutrient solution at 21$^{\circ}C$ and 80-95% relative humidity. The model estimates crop net $CO_2$ uptake for short time intervals during the day based on short-term data of daily radiation, temperature and $CO_2$ concentration. During the photosynthesis measurements, $CO_2$ concentrations in both compartments and in the basement were measured every minute. This was also done for the flow of pure $CO_2$ into the compartment, global radiation, photosynthetic active radiation inside the compartment, temperature and relative humidity. Crop growth models summarize our knowledge on crop behavior and have as such a wide range of applications in analysis, crop management and thus as a farm management tool.

• The Korean Journal of Pain
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• v.22 no.1
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• pp.21-27
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• 2009

Background: The neuropathic pain arising from nerve injury is difficult to treat and the therapeutic effects of opioid drugs remain debatable. Agonists acting at the ${\alpha}_2$ adrenergic and opioid receptors have analgesic properties and they act synergistically when co-administered in the spinal cord. The lack of subtype-selective pharmacological agents has previously impeded the synergistic effects that are mediated by the adrenergic receptor subtypes. Methods: We created neuropathic pain model by ligating the L5 spinal nerve in Sprague-Dawley rats (n = 18). We divided the rats into three groups (n = 6 for each group), and we administered intraperitoneal morphine (1 mg/kg, 3 mg/kg, 5 mg/kg) and then we measured the mechanical allodynia with using von-Frey filaments for 8 hours. We then injected morphine (5 mg/kg) intraperitoneally, twice a day for 2 weeks. We measured the tactile and cold allodynia in the morphine group (n = 9) and the saline group (n = 9). After 2 weeks, we decapitated the rats and harvested the spinal cords at the level of lumbar enlargement. We compared the ${\alpha}_2$ subtype mRNA expression with that of control group (n = 6) by performing real time polymerase chain reaction (RTPCR). Results: Intraperitoneal morphine reduced the neuropathic pain behavior in the dose-dependent manner. Chronic morphine administration showed an antiallodynic effect on the neuropathic pain rat model. The rats did not display tolerance or hyperalgesia. The expression of the mRNAs of the ${\alpha}_{2A}$, ${\alpha}_{2B}$, ${\alpha}_{2C}$ subtypes decreased, and morphine attenuated this effect. But we could not get statistically proven results. Conclusions: Systemic administration of morphine can attenuate allodynia during both the short-term and long-term time course. Morphine has an influence on the expression of ${\alpha}_2$ receptor subtype mRNA. Yet we need more research to determine the precise effect of morphine on the ${\alpha}_2$ subtype gene expression.

• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.97-105
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• 2002

This study attempts to develop a program for obesity prevention and management for students in primary, middle, and high school and was carried based on the program development process as suggested by Ewles and Simnett. Data were collected from September 1st to September 30th, 2000. The study method is as follows: 1) Reviewing the present obesity control programs practiced in primary, middle, and high school (196 schools total) in metropolitan, medium-sized, and small cities, 2) Surveying obesity students'(682 students total) perception of the obesity management in their school. 3) Reviewing the annual plan for obesity in primary, middle, and high schools 4) Analyzing the educational data (CD, VIDEO) for obesity The results are as below: I. The media researched related to obesity were mainly CD and video, aimed primarily primary school students and are biased in nature. 2. The results of how to manage obesity in students: the difficulty of obesity education in the primary school, is the arousal of a sense of shame among obese students and the lack of various educational data are the most. In the middle and high schools, a lack of various educational data, and no time or lack of time were prevailing concerns. Paramount in managing obesity is weight control, as answered by majority of primary, middle, and high school students. The major problem of obesity management is the non-cooperation of children. 3. Asked whether the weight controlling aspect of health care class was helpful or not, 51.4% of primary school students, and 71.6% of middle and high school students answered not. The most popular educational method used in health care class is the computer, with a 56.4% approval rating. Most 43.5% of respondents answered that they wanted the content of obesity management program to focus on how to lose weight. Therefore, based on the results, the obesity management program is constructed to the steps of assessment, planning, implementation, and evaluation. Assessment includes administering surveys on health needs among students and their parents and physique tests. Planning includes the set-up of long term and short term educational goal and the establishment of an operation system. Implementation includes education, exercise, behavior modification, and health service programs. Evaluation includes step-by-step evaluations for obesity reduction. After this study is conducted, the following should be further researched: More practical and systematic obesity management programs should be developed for the evaluation results. In addition, it is important to develop an appropriate media for obesity management the primary, middle and high school students.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.283-288
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• 2019

MCrAlY overaly coatings are used as oxidation barrier coatings to prevent degradation of the underlying substrate in high temperature and oxidizing environment of the hot section of gas turbines. Therefore, oxidation resistance in high temperature is important property of MCrAlY coatings. Also, coefficients of thermal expansion (CTE) of MCrAlY have middle value of that of Ni-based superalloys and oxides, which have the effect of preventing the delamination of the surface oxides. Cyclic oxidation test is one of the most useful methods for evaluating the high temperature durability of coatings used in gas turbines. In this study, NiCoCrAlY overlay coatings were formed on Inconel 792(IN 792) substrates by vacuum plasma spraying process. Vacuum plasma sprayed NiCoCrAlY coatings and IN 792 susbstrates were exposed to 1000℃ one-hour cyclic oxidation environment. NiCoCrAlY coatings showed lower weight gain in short-term oxidation. In long-term oxidation, IN 792 substrates showed higher weight loss due to delamination of surface oxide but NiCoCrAlY coatings showed lower weight loss. X-ray diffraction (XRD) analysis showed α-Al2O3 and NiCr₂O₄ was formed during the cyclic oxidation test. Through cross-section observation using scanning electron microscopy (SEM) and electron back scatter diffraction (EBSD) analysis, thermally grown oxide (TGO) layer composed of α-Al₂O₃ and NiCr₂O₄ was formed and the thickness of TGO increased during 1000℃ cyclic oxidation test. β phase in upper side of NiCoCrAlY coating was depleted due to oxidation of Al and outer beta depletion zone thickness also increased as the cyclic oxidation time increased.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.281-291
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• 1996

458 female workers working in the small and medium scaled industries in Inchon area were surveyed to study their general characteristics, health behavior, working and environmental conditions, awareness of exposure at hazardous materials, current health status, and degree of working satisfaction. Self-administered questionnaire was distributed to the female workers with the explanation by trained interviewer on the purpose of survey and the method how to answer. The results were as follows : (1) 75.5% of the respondents are living with their families and others are living in domitary or rent house for herself. Age distribution ranges from teenagers to warren in their forties. In marital status 69.0% of workers are single and 31.0% of them have ever married. 69.4% of workers are high school graduate. The size of factory is 48.3% with less than 300 workers, 42.1% with 300~500 workers. (2) Most of the workers(86.7%) are full time workers, 52% of the respondents have working experiences in other factories. More than 65% have fewer than 5 years working experience. (3) The awareness of exposure at noise was 33% of respondents, it was significantly different by skilled status. The awareness of exposure at dust, other hazardous material was each 13.3%, 12.4% of respondents. (4) 26% of them are unsatisfied with their working cognitions and 43.7% of them are unsatisfied with their welfare in occupational system unsatisfactory rate of promotion is higher in the unmarried workers(45.6%), skilled workers(47.2%), full time workers(47.4%), long term workers(50%), and awareness group of exposure hazardous material(51.3%), compared to married women workers, unskilled workers, part-time workers, short term workers and unawareness group of exposure at hazardous materials. (5) The index of working satisfaction is rated on a scale of 1 to 10 with the higher point indicating higher satisfaction. Among the selected variables, marital status, working status, the awareness of exposure at hazardous materials, were statistically significant with the index of working satisfaction. (6) By multiple regression analysis showed that the determinant factors of index of working condition were health index, the awareness of exposure at dust, the awareness of exposure other hazardous materials, marital status and working period. In conclusion, there is a significant relationship between the awareness of exposure at hazardous material the index of working satisfaction. Therefore if the workers are less exposed to the hazardous material and are educated properly they will be more satisfied with their work thus improving their health and productivity. Finally, with the result of this study, there is a great need for the development of a health promotion program and a welfare policy for small-scale factories.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.1-12
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• 2006

As national economies globalize, demand for intercontinental container shipping services is growing rapidly, providing a potential economic boon for the countries and communities that provide port services. On the promise of profits, many governments are investing heavily in port infrastructure, leading to a possible glut in port capacity, driving down prices for port services and eliminating profits as ports compete for business. Further, existing ports are making strategic investments to protect their market share, increasing the chance new ports will be overcapitalized and unprofitable. Governments and port researchers need a tool for understanding how local competition in their region will affect demand for port services at their location, and thus better assess the profitability of a prospective port. We propose to develop such a tool by extending our existing simulation model of global container traffic to incorporate demand-side shipper preferences and supply-side strategic responses by incumbent ports to changes in the global port network, including building new ports, scaling up existing ports, and unexpected port closures. We will estimate shipper preferences over routes, port attributes and port services based on US and international shipping data, and redesign the simulation model to maximize the shipper's revealed preference functions rather than simply minimize costs. As demand shifts, competing ports will adjust their pricing (short term) and infrastructure (long term) to remain competitive or defend market share, a reaction we will capture with a game theoretic model of local monopoly that will predict changes in port characteristics. The model's hypotheses will be tested in a controlled laboratory experiment tailored to local port competition in Asia, which will also serve to demonstrate the subtle game theoretic concepts of imperfect competition to a policy and industry audience. We will apply the simulation model to analyze changes in global container traffic in three scenarios: addition of a new large port in the US, extended closure of an existing large port in the US, and cooperative and competitive port infrastructure development among Korean partner countries in Asia.

• Korean Journal of Health Education and Promotion
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• v.14 no.1
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• pp.73-95
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• 1997

Elderly problem from being aging society, especially health related problem of the elderly is very serious in many parts of this country. The reason is that most of geriatric disease are chronic and debilitating. The cause of chronic and debilitating disease are bad lifestyle and wrong health habit. Health is affected by a result of interaction of environment and human being. Because of difference of lifestyle between a city and a farm village, health behavior and health status of urban elderly and rural elderly may be dissimilar. Thus the purpose of this study was to grasp health behavior and health status, to identify the factors that effect on health status of the elderly. The subfects for this study, 488 persons aged 60 and over who live in Seoul or Cheonbuk Province. The preliminary survey was carried out from Aug. 19, to Aug. 22, 1996. With complement of questions, main survey was carried out from Sep. 29, to Oco. 10, 1996. The data was analysed by using in SPSS/PC+ program. The results were as follows. 1. General Characteristics 1) In the individual characteritics of the respondents, Seoulites aged 80 and over were 24.7%, the average age was 73.14 years old and rural residents aged 60-69 were 63.7%, the average age was 68.90 years old. In Seoul, 142 men and 101 women were respondents. In Cheonbuk Province, 101 men and 144 women were answered. In Seoul, those who graduated form elementary school were 35.4%, in farming region, illiteracy persons were 44.9%. In Seoul, 47.7% of respondents had spouse and in farming village, 66.1% of respondents had spouse. 39.0% of respondents who's imcome type was independent were Seoulite, and 66.1% of respondents who's income type was independent were rural residents. Employed persons in Seoul and in rural region were 16.9% and 62.0%. 2. Health Behavior 1) For the health behavior total score, the difference by region was not statistically significant. But the score of individual item was different and statistically significant. 2) For the Seoulites, younger person(p〈0.01), the female(p〈0.001) showed better health behavior and for the farming village residents, younger person(p〈0.01), the female(p〈0.01), independent income type(p〈0.05), employed person(p〈0.05) showed better health behavior. 3. Health Status 1) For the self-rated health status total score, the difference by region was statistically significant and individual item score was different and statistically significant. For ADL and IADL total score, the difference by region was not statistically significant, but individual item score was different and statistically significant. 2) For the Seoulites, woman(p〈0.05), lower education(p〈0.00l), independent income type(p〈0.05) showed higher score in self-rated health status. For rural residents, woman(p〈0.05), lower education(p〈0.01), independent Income type(p〈0.001) showed higher score in self-rated health status. For the Seoul residents, younger person(p〈0.001), employed(p〈0.05) showed higher score in ADL and IADL, and for the farm area residents, younger person(p〈0.001), higher education(p〈0.01), having spouse(p〈0.001), family type(p〈0.01) showed higher score In ADL and IADL. 3) For the Seoulites, drinking(p〈0.05), breakfast(p〈0.05), exercise(p〈0.05) and for the rural residents, drinking(p〈0.05), deep sleeping(p〈0.05), exercise(p〈0.01), washing hands before meal(p〈0.01) showed higher score In self-rated health status. For the Seoulites, deep sleeping(p〈0.05), exercise(p〈0.05) and for the farm village residents, fruit(p〈0.05), deep sleeping(p〈0.05), exercise(p〈0.001) showed higher score in ADL and IADL. We carried out this study to analyze the effectiveness through health education program in short term which was performed to use the special subject activities. This study was conducted on 63 students who were first grade in S Junior High School from Dec. 1995 to Feb. 1996. To analyze the effectiveness, we performed the Pretest, 1st Posttest, and 2nd Posttest for learned health knowledge. The results were as follows: 1. Most of the students(69.8%) responded that their health were good, and they got the information for health through Mass Com.. The students who had experience of health education were 15.9%, and the 77.8% of the respondents needed the health education. 2. The means of health knowledge on tests were 18.2(Pretest), 21.5(1st Posttest), and 21.4(2nd Posttest). Increase of health knowledge between Pretest and 1st Posttest was 10.9%. 3. The mean of differences between Pretest and 1st Posttest was 3.26, it was significant(p〈0.01). And the mean of differences between Pretest and 2nd Posttest was 3.19, it was significant(p〈0.01);however, the mean of differences between 1st Posttest and 2nd Posttest was not significant(p=0.2514). 4. The significant main contents were Health Facilities(d=0.42), Pregnancy and Labor(d=0.39), Hygiene(d=0.35), Safety Education(d=0.66), and Drug Abuse(d=0.60)(p〈0.01).