• Explosives and Blasting
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• v.37 no.3
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• pp.13-24
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• 2019

This paper was prepared to investigate the behavior of fragments in underwater torpedo explosion beneath a frigate or surface ship by using an explicit finite element analysis. In this study, a fluid-structure interaction (FSI) methodology, called the multi-material arbitrary Lagrangian-Eulerian (MM-ALE) approach in LS-DYNA, was employed to obtain the responses of the torpedo fragments and frigate hull to the explosion. The Euler models for the analysis were comprised of air, water, and explosive, while the Lagrange models consisted of the fragment and the hull. The focus of this modeling was to examine whether a worst-case fragment could penetrate the frigate hull located close (4.5 m) to the exploding torpedo. The simulation was performed in two separate steps. At first, with the assumption that the expanding skin of the torpedo had been torn apart by consuming 30% of the explosive energy, the initial velocity of the worst-case fragment was sought based on a well-known experimental result concerning the fragment velocity in underwater bomb explosion. Then, the terminal velocity of the worst-case fragment that is expected to occur before the fragment hit the frigate hull was sought in the second step. Under the given conditions, the possible initial velocities of the worst-case fragment were found to be very fast (400 and 1000 m/s). But, the velocity difference between the fragment and the hull was merely 4 m/s at the instant of collision. This result was likely to be due to both the tremendous drag force exerted by the water and the non-failure condition given to the frigate hull. Anyway, at least under the given conditions, it is thought that the worst-case fragment seldom penetrate the frigate hull because there is no significant velocity difference between them.

• The Journal of Korean society of community based occupational therapy
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• v.10 no.3
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• pp.15-26
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• 2020

Objective : Due to the rapid aging of the country, the elderly population is increasing and the ratio of face-to-face meetings with the elderly in major areas of occupational therapy is high. The purpose of this study was to investigate the overall perception of the elderly and the status of communication with the elderly. Methods : This survey was conducted From April to June 2020. Occupational therapists who provide interventions for the elderly in hospitals and public health centers across the country were collected using online questionnaires. A total of 91 questionnaires were collected through a self-administered questionnaire, of which 82 were used for data analysis, excluding 9 with insufficient responses. Results : Occupational therapists generally had a lot of negative perceptions of the elderly. In addition, as factors that hindered communication with the elderly, they responded in order of hearing-related, language understanding related, and articulation related. Lastly, occupational therapists were found to induce smooth communication with the elderly in the order of conversation response management, emotional expression, understanding enhancement, and relationship control. Conclusions : Occupational therapists are health care professionals who play a major role in improving the subjects' social participation and quality of life. Therefore, it is necessary to provide professional therapeutic interventions and related education using improved communication skills along with an understanding of the elderly's communication skills and their level of communication.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.1
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• pp.8-17
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• 2023

In conventional liquid crystal display(LCD) manufacturing process, Indium Tin Oxide(ITO) as transparent electrode and rubbing process of polyimide as alignment layer are essential process to apply electric field and align liquid crystal molecules. However, there are some limits that deposition of ITO requires high vacuum state, and rubbing process might damage the device with tribolectric discharge. In this paper, we made nanocomposite with PEDOT:PSS and MWNT to replace ITO and constructed alignment layer by nano imprint lithography with nano wrinkle pattern, to replace rubbing process. These replacement made that only one PEDOT:PSS/MWNT film can function as two layers of ITO and polyimide alignment layer, which means simplification of process. Transferred nano wrinkle patterns functioned well as alignment layer, and we found out lowered threshold voltage and shortened response time as MWNT content increase, which is related to increment of electric conductivity of the film. Through this study, it may able to contribute to process simplification, reducing process cost, and suggesting a solution to disadvantage of rubbing process.

• Applied Chemistry for Engineering
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• v.35 no.1
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• pp.16-22
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• 2024

Polymer electrolyte membrane fuel cells have the advantage of low operating temperatures and fast startup and response characteristics compared to others. Simulation studies are actively researched because their cost and time benefits. In this study, the resistance of water residual in the gas diffusion layer (GDL) of the unit cell was added to the existing equation to compare the actual data with the model data. The experiments were conducted with a 25 cm² unit cell, and the samples were separated into stopping times of 0, 10, and 60 minutes following primary impedance measurement, activation, and polarization curve data acquisition. This gives 0, 10, and 60 minutes for the residual water in the GDL to evaporate. Without the rest period, the magnitude of the performance improvement was not significantly different at the same potential and flow rate, but the rest period did improve the performance of the membrane electrode assembly when measuring impedance. By changing the magnitude of the resistance reduction to an overvoltage, the voltage difference between the fuel cell model with and without residual water was compared, and the error rate in the high current density region, which is dominated by concentration losses, was reduced.

• Journal of Hospice and Palliative Care
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• v.4 no.1
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• pp.4-13
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• 2001

Purpose : Since the acquired immune deficiency syndrome (AIDS) was first recognized in the United States in the summer of 1981, the number of these patients has been increasing in the world. But do not find out a cure and a vaccine for ARS (5). And so, the best treatment for AIDS is the prevention. People can find out accurate knowledge about AIDS, and they can prevent themselves from AIDS approximately 100%. In this study, we investigate with AIDS knowledge and attitudes in unmarried young men (<24 age) and suggest accurate preventive education for AIDS and good sexual behaviors. Methods : Un-married young soldiers and college students who were not diagnosed as AIDS until June 30, 2000 were included in the study. The study included a total of 923 men. A self evaluation questionnaire, included questions on 36 items(the part of demographic data - 9; the part of knowledge - 20; the part of attitudes - 8), was drawn up by three physicians. The demographic data, AIDS knowledge and attitudes were analyzed by chi-square analysis, and the total score of AIDS knowledge - comparison according to demographic factors and attitudewere analyzed by one-way ANOVA test. Results : In demographic characteristics, as for the first recognized time of AIDS, most of men knew it when they were in their middle school, as for sources of information on AIDS, most of them knew it through the TV-media, and as for the educational need about AIDS, most of them agreed with it. In AIDS knowledge, mean scores were $14.0{\pm}1.8$ (70.3%). Items of the misconceptions concerning AIDS, reported as less than 50% correct answers, were 6 among 20 items (30%). In AIDS attitudes, as for the item about that if I will be an AIDS patient, I will have an AIDS treatment, it showed that the number of men agreed with 759 (82.2%), and as for the item about that I will help for AIDS patient even though I don't know him, it showed that the number of them agreed with 412 (45.8%). In correlation of AIDS knowledge and demographic factors, the mean scores of knowledge of men with higher than college degree were higher than them of others. The mean scores of knowledge of men with total income of family with more than US$1667 were higher than them of others. The mean scores of knowledge of men with sources of information on AIDS through the TV-media were higher than them of others. And the mean scores of knowledge of men with past medical history of STD(sexually transmitted disease) were higher than them of others. Conclusions : The higher the knowledge he has, the lower the possibility of risk and the more positive the attitude he has. And then we think that the education program for AIDS will be included as a regular part of the curriculum in high school, and young men must be effectively educated by it.

• Clean Technology
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• v.25 no.4
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• pp.316-323
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• 2019

In order to enhance combustion efficiency and reduce atmosphere pollutants, it is essential to measure carbon monoxide (CO) concentration precisely in combustion exhaust. CO is the important gas species regarding pollutant emission and incomplete combustion because it can trade off with NOx and increase rapidly when incomplete combustion occurs. In the case of a steel annealing system, CO is generated intentionally to maintain the deoxidation atmosphere. However, it is difficult to measure the CO concentration in a combustion environment in real-time, because of unsteady combustion reactions and harsh environment. Tunable Diode Laser Absorption Spectroscopy (TDLAS), which is an optical measurement method, is highly attractive for measuring the concentration of certain gas species, temperature, velocity, and pressure in a combustion environment. TDLAS has several advantages such as sensitive, non-invasive, and fast response, and in-situ measurement capability. In this study, a combustion system is designed to control the equivalence ratio. Also, the combustion exhaust gases are produced in a Liquefied Petroleum Gas (LPG)/air flame. Measurement of CO concentration according to the change of equivalence ratio is confirmed through TDLAS method and compared with the simulation based on Voigt function. In order to measure the CO concentration without interference from other combustion products, a near-infrared laser at 4300.6 cm^-1 was selected.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.195-201
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• 2014

This study was conducted to investigate the current status of hygiene performance and food preparation/storage condition in restaurants during the summer season in order to evaluate the sanitary management systems in restaurants against climate change. Total 30 restaurants located in Gyeonggi participated in a survey in which they were asked current hygiene performance, food preparation/storage condition, and purchasing practices for 5 food ingredients. As results, regarding the performance degree of respondents on food hygiene management, the average scores of 9 questions were well over 4 points. However, only 6.83% of the respondents claimed that they use sanitizers (chlorine) to disinfect food ingredients. About food storage condition, a high proportion of respondents said that they store food materials in plastic bags or airtight containers following pretreatment and use refrigerator for the storage of pretreated food materials. However, 5.55% and 14.85% of respondents answered that they store pretreated food materials in the kitchen or inside of dining room, respectively. Respondents (21.50%) answered that they store pretreated food materials for more than 6 hours before cooking. Therefore, food materials need to be disinfected properly with sanitizer to remove microbial contamination and stored at refrigerator using closed bags or containers before cooking in order to prevent foodborne disease in restaurants especially during summer season.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.343-360
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• 2011

The objective of this paper is to analyze and characterize to simulate routing observations on end-to-end routing circuits and a ping experiment of a virtual network after modeling, such as IPv6 migration, an OSPFv3 routing experiment based on an IPv6 environment, and a ping experiment for IPv4/IPv6 dual-stack networks and IPv6 network for OSPFv3 routing using IPv6 planning and operations in an OPNET Modeler. IPv6 deployment based largely on the integrated wired and wireless network was one of the research tasks at hand. The previous studies' researchers recommended that future research work be done on the explicit features of both OSPFv3 and EIGRP protocols in the IPv4/IPv6 environment, and more research should be done to explore how to improve the end-to-end IPv6 performance. Also, most related work was performed with an IPv4 environment but lacked studies related to the OSPFv3 virtual network based on an end-to-end IPv6 environment. Hence, this research continues work in previous studies in analyzing IPv6 migration, an OSPFv3 routing experiment based on IPv6, and a ping experiment for IPv4/IPv6 dual-stack networks and IPv6 network for OSPFv3 routing. In the not too distant future, before enabling the default IPv6, it would help to understand network design and deployment based on an IPv6 environment through IPv6 planning and operations for the end-user perspective such as success or failure of connection on IPv6 migration, exploration of an OSPFv3 routing circuit based on an end-to-end IPv6 environment, and a ping experiment for IPv4/IPv6 dual-stack networks and IPv6 network for OSPFv3 routing. We were able to observe an optimal route for modeling of an end-to-end virtual network through simulation results as well as find what appeared to be a fast ping response time VC server to ensure Internet quality of service better than an HTTP server.

• Biomedical Science Letters
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• v.4 no.2
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• pp.143-151
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• 1998

To study the incidence and epidemiological factors of uterine cervical cancer in medical underserved area females, the questionnaire survey and Pap. smear for uterine cervical cancer was done on total 330 women who lived in Ullungdo from 5th to 12th August, 1998. The results were summarized as follows： The age distribution of subjects was 50s (24.5%), 60s (24.5%) and their educational level was “no schooling” (14.2%) and “elementary school” (42.7%). The first coital age of subjects was 19∼21yrs (30.0%), 16∼18yrs (13.9%) and the first pregnancy age was 22∼24yrs (36.7%) and 19∼21yrs (30.0%). The frequency of total pregnancy of subjects was over 5 times (52.1%). The frequency of total delivery was “3∼4 times” (35.5％) and “5∼6 times” (15.2％). 68.8% of subjects had experience of abortion and 80.0% of their husband were on the phimosis. 172 (52.1%) subjects had gynecological symptoms, their symptoms were leukorrhea (48.3%), pruritus (21.5%) and leukorrhea with pruritus (20.3%). 63.9% of total subjects have been received Pap. smear and the frequency of their Pap. smear was “only 1 time” (44.1 ％), “irregularly” (30.3%) and the reason of respondents who have not been received Pap. smea. was “no specific symptom” (51.3%). Among the 330 women screened there were negative (45.8%), inflammation (47.3%), trichomoniasis and candidiasis (1.8%), atypical cells (4.5%) and dysplasia (0.6%).

• Journal of agricultural medicine and community health
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• v.37 no.3
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• pp.131-144
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• 2012

Objectives: This study was performed to identify the associations of empowerment and social capital (such as social participation and trust) with self-rated health in Korean communities with poor health. Methods: This study used the data from community health interviews conducted at 29 administrative sections (dong, eup, or myeon) with high mortality from August to October in both 2010 and 2011 as part of the Health Plus Happiness Plus Projects in Gyeongsangnam-do Province. The study subjects comprised 6,383 individuals composed of approximately 220 adults randomly sampled from each administrative section. The empowerment was measured with five-point Likert scale responses to seven perceived control questions (two at the individual level, five at the community level). The social participation was measured with 'participation in formal and/or informal group' and trust using responses to three questions about trust of others. Results: The high empowerment scores at both individual and community levels, social participation in informal groups, and high trust level had independent and significant associations with good self-rated health after adjusting for socio-demographic factors (sex, age, marital status, occupation, and food affordability) and health behaviors (smoking, alcohol drinking, and exercise) in the logistic regressions. There were weak but significant associations among empowerment, social participation, and trust levels. Conclusions: Empowerment, social participation, and trust were weakly inter-related and significantly associated with self-rated health. More studies are warranted for empowerment and other social capital indices in health promotion.