• Tunnel and Underground Space
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• v.32 no.6
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• pp.491-501
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• 2022

Bentonite has been proposed as a buffer and backfill material for high-level radioactive waste repository. Under such repository environment conditions, bentonite is subjected to combined thermal, hydrological, mechanical, and chemical processes. This study evaluates the feasibility of applying X-ray CT technology on the characterization of bentonite under hydration conditions using a newly developed testing cell. The cylindrical cell is made of platic material, with a removable cap to place the sample, enabling to apply vertical pressure on the sample and to measure swelling pressure. The hydration test was carried out with a sample made of Gyeonju bentonite, with a dry density of 1.4 g/cm³, and a water content of 20%. The sample had a diameter of 27.5 mm and a height of 34 mm. During the test, water was injected at a constant pressure of 0.207 MPa, and lasted for 7 days. After one day of hydration, bentonite swelled and filled out the space inside the cell. Moreover, CT histograms showed how the hydration process induced an initial increase and later progressive decrease on the density of the sample. Detailed profiles of the mean CT value, CT standard deviation, and CT gradient provided more details on the hydration process of the sample and showed how the bottom and top regions exhibited a decrease on density while the middle region showed an increase, especially during the first two days of hydration. Later, the differences in CT values with respect to the initial state decreased, and were small at the end of testing. The formation and later reduction of cracks was also characterized through CT scanning.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1635-1650
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• 2023

Under global warming, the steadily increasing sea surface temperature (SST) severely impacts marine ecosystems,such as the productivity decrease and change in marine species distribution. Recently, the catch of Todarodes Pacificus, one of South Korea's primary marine resources, has dramatically decreased. In this study, we analyze the marine environment that affects the formation of fishing grounds of Todarodes Pacificus and develop seasonal habitat suitability index (HSI) models based on various satellite data including Geostationary Ocean Color Imager (GOCI) data to continuously manage fisheries resources over Korean exclusive economic zone. About 83% of catches are found within the range of SST of 14.11-26.16℃,sea level height of 0.56-0.82 m, chlorophyll-a concentration of 0.31-1.52 mg m^-3, and primary production of 580.96-1574.13 mg C m^-2 day^-1. The seasonal HSI models are developed using the Arithmetic Mean Model, which showed the best performance. Comparing the developed HSI value with the 2019 catch data, it is confirmed that the HSI model is valid because the fishing grounds are formed in different sea regions by season (East Sea in winter and Yellow Sea in summer) and the high HSI (> 0.6) concurrences to areas with the high catch. In addition, we identified the significant increasing trend in SST over study regions, which is highly related to the formation of fishing grounds of Todarodes Pacificus. We can expect the fishing grounds will be changed by accelerating ocean warming in the future. Continuous HSI monitoring is necessary to manage fisheries' spatial and temporal distribution.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.253-270
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• 2023

Research on investment determinants of accelerators, which are attracting attention by greatly improving the survival rate of startups by providing professional incubation and investment to startups at the same time, is gradually expanding. However, previous studies do not have a theoretical basis in developing investment determinants in the early stages, and they use factors of angel investors or venture capital, which are similar investors, and are still in the stage of analyzing importance and priority through empirical research. Therefore, this study verified for the first time in Korea the discrimination and effectiveness of investment determinants using accelerator investment determinants developed based on the business model innovation framework in previous studies. To this end, we first set the criteria for success and failure of startup investment based on scale-up theory and conducted a survey of 22 investment experts from 14 accelerators in Korea, and secured valid data on a total of 97 startups, including 52 successful scale-up startups and 45 failed scale-up startups, were obtained and an independent sample t-test was conducted to verify the mean difference between these two groups by accelerator investment determinants. As a result of the analysis, it was confirmed that the investment determinants of accelerators based on business model innovation framework have considerable discrimination in finding successful startups and making investment decisions. In addition, as a result of analyzing manufacturing-related startups and service-related startups considering the characteristics of innovation by industry, manufacturing-related startups differed in business model, strategy, and dynamic capability factors, while service-related startups differed in dynamic capabilities. This study has great academic implications in that it verified the practical effectiveness of accelerator investment determinants derived based on business model innovation framework for the first time in Korea, and it has high practical value in that it can make effective investments by providing theoretical grounds and detailed information for investment decisions.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.400-412
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• 2023

In this study, the biogeochemistry management (BGC-MAN) model was applied to North and South Korea pine and oak forest stands to evaluate the Net Primary Productivity (NPP), an indicator of forest ecosystem productivity. For meteorological information, historical records and East Asian climate scenario data of Shared Socioeconomic Pathways (SSPs) were used. For vegetation information, pine (Pinus densiflora) and oak(Quercus spp.) forest stands were selected at the Gwangneung and Seolmacheon in South Korea and Sariwon, Sohung, Haeju, Jongju, and Wonsan, which are known to have tree nurseries in North Korea. Among the biophysical information, we used the elevation model for topographic data such as longitude, altitude, and slope direction, and the global soil database for soil data. For management factors, we considered the destruction of forests in North and South Korea due to the Korean War in 1950 and the subsequent reforestation process. The overall mean value of simulated NPP from 1991 to 2100 was 5.17 Mg C ha^-1, with a range of 3.30-8.19 Mg C ha^-1. In addition, increased variability in climate scenarios resulted in variations in forest productivity, with a notable decline in the growth of pine forests. The applicability of the BGC-MAN model to the Korean Peninsula was examined at a time when the ecosystem process-based models were becoming increasingly important due to climate change. In this study, the data on the effects of climate change disturbances on forest ecosystems that was analyzed was limited; therefore, future modeling methods should be improved to simulate more precise ecosystem changes across the Korean Peninsula through process-based models.

• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.335-344
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• 2024

In this study, we aim to investigate the correlation between the lateral images of Korean skulls and the angle between the OML and the Body of the Mandible. Additionally, we seek to provide criteria for the ease of positioning in clinical settings and establish standardized imaging procedures for the PNS Water's view examination. This study was conducted on a total of 202 patients who visited the radiology department of a general hospital and examined the skull lateral radiography. In addition to the patient images, skull phantoms were also utilized, and images were obtained using GC85A and EOS equipment. In this research, abbreviations related to the angle of the Body of Mandible were defined using PACS on lateral images. Measurements were taken for various angles, including ramus of mandible angle(RIA), accurate OML angle(TIA), OML and IR Angle(OIA), total mandibular length(TML), ramus height(RH), the angle between the pogonion, gonion, and condylion(MA). The validity of these measurements was confirmed using the skull phantom in the study. The age-specific average range for RIA was 22.67° to 26.04°, with measurements of 23.14° for males and 24.78° for females. The age-related mean ranges for TIA and OIA were 35.98° to 38.31° and 72.27° to 75.25°, respectively. For males, TIA was 36.74° and OIA was 72.73°, while for females, TIA was 36.43° and OIA was 73.38°. The age-dependent measurements for TML and RH ranged from 85.73 mm to 89.60 mm and 62.60 mm to 70.87 mm, respectively. Male values were 90.54 mm and 70.78 mm, while female values were 85.13 mm and 61.54 mm for TML and RH, respectively. The age-specific average range for MA was 55.95° to 58.63°, with measurements of 57.96° for males and 57.76° for females. Correlation analysis revealed a positive correlation between RIA and OIA, as well as between RIA and TIA. Based on the results of this study, which indicate a positive correlation between the angle of the Body of Mandible and the OML, it can be inferred that adjusting the mandible vertically to align with the imaging receptor may contribute to more accurate image acquisition during PNS Water's view examination. Therefore, it is believed that there is value in utilizing this relationship as a criterion for establishing new positioning standards, which could enhance the utility of a new positioning guide.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.4
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• pp.243-254
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• 2024

In recent years, as support for venture companies and performance increase, investment scale increases. To support them goverment operates venture firm confirmation system as a part of a variety of policies. Many studies suggest venture confirmation system offer the practical assistance on performance of venture companies. However, simply venture firm confirmation system affects on performance of venture companies. This study sought to develop a theoretical research model about the impact of innovation capabilities and industrial property rights on venture companies' financial performance and technological capabilities through the venture company confirmation system. The following hypotheses were tested. First, the innovation capabilities of venture companies such as development capability, manufacturing capability, marketing capability, level of cost leadership, level of high added value, degree of clarity of business model, and degree of innovation of business model have a significant impact on the venture company confirmation system. Second, the industrial property rights of venture companies, such as the number of domestic industrial property rights, foreign industrial property rights, industrial property rights in domestic applications, and industrial property rights in overseas applications, do not have a significant impact on the venture business confirmation system. Third, the benefits of the venture business confirmation system, such as promotion of technology development, advertising effects, tax benefits, securing excellent human resources, financing and investment incentives, advantageous participation in government support systems, and deregulation, are related to the financial performance of venture businesses such as sales and operating profit., net profit and technological level. Lastly, it was confirmed that, except for research and development type venture companies, innovation capabilities and industrial property rights do not have a significant impact on financial performance and technological capabilities through the venture confirmation system. The implications of this study mean that in situations where a company's innovation capabilities are lacking, the supply and demand of the venture business confirmation system is weak. Therefore, in order to improve the benefits of the venture business verification system, it is necessary to operate the venture business verification system benefits mainly for companies with high corporate capabilities. Next, it means that industrial property rights are not related to the venture business confirmation system. Therefore, there will be no need to consider industrial property rights as an important matter in the certification of the venture business verification system. Lastly, the higher the level of benefits from the venture business confirmation system, the greater the company's performance and technological capabilities. Therefore, efforts should be made to utilize the venture business verification system in a way that can improve performance or technology through the benefits of the venture business verification system.

• Journal of agricultural medicine and community health
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• v.8 no.1
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• pp.44-65
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• 1983

As a part of the epidemiological studies of clonorchiasis, this study was conducted to evaluate the current endemicity and the natural transition of the Clonorchis infection in Gimhae Gun and delta area a high endemic area in Korea in recent years, prior to the introduction of praziquantel which will eventually influence the status of the prevalence. The data obtained in this study in 1983 were evaluated for natural transition of the infection in comparison with those obtained 16 years ago in 1967 by the author(Kim, 1974). The areas of investigation, villages and schools surveyed, methods and techniques used in this study were the same as in 1967, except for the contents of the questionnaire for raw freshwater fish consumption by the local inhabitants. 1) The prevalence rate of clonorchiasis in the general population of the villages was 48.1% on the average out of a total of 484 persons examined. The average of those of the riverside-delta area was 65.2% and 43.0% in the inland area. Among the schoolchildren, the prevalence rate was 8.2% on the average out of a total of 1,423 examined. By area, the prevalence rate was 10.8% in the riverside delta area and 2.8% in the inland area. By sex, difference in the prevalence was seen only in the inhabitants of the inland area showing 52.4% in the male and 33.5% in the female. 2) In the natural transition of the infection, the prevalence rate among the inhabitants has decreased from 68.8% in 1967 to 48.1% in 1983, and in the schoolchildren from 56.4% in 1967 to 8.2% in 1983. The reduction rate was higher in the riverside-delta area than in the inland area. 3) In the prevalence rate by age, 11.9% was first seen in the 5-9 age group and the rate gradually increased up to 75.0% in the 50-59 age group. By sex, the rate was higher in the male than in the female in the 20-29 age group and over. 4) In the natural transition of the prevalence rate by age, the reduction rate of the infection during the past 16 years was greater in the younger age groups up to the 40-49 age group and reached the same level in the age group 50-59. Reduction was seen again in the age group over 60s. By sex, the reduction rate was greater in the female than in the male in the 20-29 age group and over. By area, the reduction rate was greater in the riverside delta area than in the inland area, particularly in the young age groups. 5) In the intensity of the infection among the cases, the mean egg out-put per mg feces per infected cases(EPmg) in the inhabitants was 6.3. EPmg of those of the river-side-delta area was 15.4 and that of the in-land was 2.8. On the other hand, in the schoolchildren, EPmg was 3.2, and no difference was seen between the two areas, the river-side-delta area and the inland area. 6) In the transition of the intensity of the infection by area, EPmg among the inhabitants inexplically increased from 7.8 in 1967 to 15.4 in 1983. This was probably caused by uneven specimen collection in the process of sampling the population. EPmg of the inhabitants in the inland area and those of the schoolchildren of both riverside delta and inland areas showed a similar decrease in the past 16 years. 7) The intensity of the infection by age showed a relatively low level in the 20-29 age group and below, and EPmg 5.1-9.5 was seen in the 30-39 age group and over. Sex, Epmg was 5.8 in the male and 4.7 the female. By in 8) In the transition of the intensity of the infection, EPmg decreased from 6.2 in 1967 to 5.4 in 1983. By age, in contrast to the figures of 1967 in which EPmg gradually increased with some fluctuation from 1.1 in the 0-4 age group to peak 10.5 in the 50-59 age group, in 1983 lower intensity of the infection was seen in the age group from 10-14 to 20-29 with the EPmg range of 0.6-2.7. 9) In the distribution of the clonorchiasis cases by the range of EPmg value, 43.2% of the cases were in 0.1 0.9 and 34.6% in 1.0-4.9. As a whole by cumulative percent, 44.6% of them were under 0.9 as light infection and 86.1% of them under 9.9 up to moderate infection. By sex, no difference was seen in Epmg. 10) In the transition of the distribution by the range of Epmg, the cases were distributed up to the range 80.0-99.9 in 1967 and to 60.0-79.9 in 1983. By cumulative percent, in the range of 0.1-0.9 and less, light infection, 34.3% of them were distributed in 1967 and 44.6% in 1983 with about 10% increase. In the range of 5.0-9.9 and less, up to moderate infection, 83.2% in 1967 and 86.1% in 1983 of the cases were seen, respectively. 11) The practice of raw freshwater fish consumption among the inhabitants seems to have decreased in recent years. Those who admitted to raw freshwater fish consumption in the last two years among the infected inhabitants were 59.3%, although 86.8% of them professed to have experience with raw freshwater fish consumption. 31.7% of those who have had experience of the raw freshwater fish consumption denied any further consumption in recent years. From an interview of 543 school-children, 24.1% of them admitted to an experience of raw freshwater fish consumption. However, those who have practised in the past two years comprized 17.9%. Those who denied raw freshwater fish consumption in recent years among those who had such experience were 26.0% out of 131 interviewed. The rate of raw freshwater fish consumption in both inhabitants and schoolchildren were higher in the male than in the female. On the contrary, the rate of those who did not practise in recent years among those who had experience of raw freshwater fish consumption was higher in the female than in the male. 12) The major reason for the reduction of raw freshwater fish consumption among the local inhabitants was the risk of the fluke infection. However, it has become apparent that such change of taste has resulted from water pollution impact which has affected throughout the areas of the freshwater systems in this locality since last several years. 13) In animal survey, Clonorchis infection was seen in 14.8% of 88 dogs examined and 3.7% of 27 house rats examined. It was noted that populations of dogs and cats have increased in the villages surveyed. Although the prevalence rate was lower in the present survey than those of 1967, the significance of the animals as the reservoir host has not changed. 14) Prevalence rate of Clonorchis infection by cercariae in the first intermediate host, Parafossarulus manchouricus, was 0.6% out of 517 snails examined. The infection rate was lower in comparison with 2.3% out of 2,124 examined in 1967. Moreover, sharp decreases in number and distribution of the intermediate host snails in many watershed areas of the huge freshwater systems in this locality seemed to reduce transmission of Clonorchis in connection with the intermediate host stage of its life cycle. 15) Clonorchis infection in the second intermediate fish hosts was relatively low. The mean number of Clonorchis metacercaria per fish in Pseudorasbora parva was 517 in 1983, whereas it was 1943 in 1968 through 1969. Environmental water pollution has also caused the decreased fish population density in these areas, and this has also apparently affected to the practice of raw freshwater fish consumption among the local inhabitants. 16) In conclusion, endemicity of Clonorchis infection in Gimhae Gum and delta area of the Nagdong River has sharply decreased during the past 16 years. The major cause of the regressive transition of the infection was the water pollution of the land water systems of this locality. The pollution has upset the ecosystems comprizing of the intermediate hosts of Clonorchis in many areas, and also affected to a significant extent to the discontinuance of the local inhabitants for raw freshwater fish consumption.

• Journal of the Korean Home Economics Association
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• v.19 no.3
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• pp.83-101
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• 1981

Under the full consideration of the growing need and importance of population education in the field of home economics in Korea, the study was carried out to verify and assess the following facts on the current issues of population education of home economists who are presently engaging in teaching professions as the teachers of middle and high school and professors of college and universities by setting its primary objectives of the study as followings; 1) to assess the degree of general knowledge and attitudes of home economists toward population education in the field of home economics, 2) to verify the problems encountered in implementing population education by home economists in its field, 3) to find an existing status of previous trainings received and other activities of population education of home economists aimed at utilizing these findings as a part of reference materials when the population education is conducted in the field of home economics. In order to attain these objectives described above, the questionnaire was carefully designed to house a total of 40 questions with good combination of multiple-choice and the simple answer questions. The mail questionnaire survey was conducted by establishing teachers of home economics at middle/high schools and college/universities as Senior Home Economists(SHE) who are from public, private liberal arts and vocational schools. The rate of response observed during the survey was 45.6 percent and the findings of the survey research are as follows: 1) Examining the status of the respondents by residence and religion, it was found that 45 percent of middle & high school teachers ar.d 59. 1 percent of college professors are residing in Seoul city area and that the largest percent of them are christian in their religion. Analyzing respondents by their ages, 56 percent of middle/high school teachers are in their 30s, 45 percent of college professors are in their 40s, and 37 percent of college teachers are in their 30s. In addition, 13 percent of the total respondents are found to be unmarried. The study also revealed that 71 percent of the college professors finished Master Degree course and 82 percent of middle/high school teachers are graduated from college level lasting 4 years. Looking over the status cf major fields of respondents, 68.4 percent of middle/high school teachers are specialized in home economic education and the college professors, on the other hand, show relatively even prortion by specializing in the order of food & nutrition science, clothes & textile science and home managerial science. As far as the length of teaching experience is concerned, a relatively longer period of teaching experience is observed in the college professors in comparison with that of middle/high school teachers. In other words, 33.3 percent of middle/high school teachers are experienced in teaching from 6 to 10 years on average while 43.9 percent of college professors show more than 16 years of experience. 2) Examining the status of existing number of children cf the respondents, one boy and one daughter pattern is predominant, showing 28.5 percent in middle/high school teachers and 21.1 percent in college professors. As for the desired number of children of unmarried respondents, it is observed that 43.8 percent of middle/high school teachers desire to have one boy and one girl, and 31.3 percent of college professors want to have one child regardless of the sex. By assessing the degree of awareness of the population education through their students, it is observed that 53 percent of middle/high school teachers and 50 percent of college professors are aware of population education in some extent and that a majority of respondents took the positive attitudes toward an inclusion of family planning components into the formal school education. Another noteworthy to observe is that a total of 84.8 percent out of middle/high school teachers pointed that the population education currently conducted at schools as a part of home economics are less sufficient than it should be. 3) Analyzing the tendency as to whether the respondents were experienced in receiving population education during the time when they were students, 75 percent of college professors and 59 percent of middle/high school teachers responded negative answers in the survey. In the mean time, a total of 50 percent of the respondents replied that they began to acknowledge the importance of population education mainly through the participation of some sort of population-education orientend seminars, experienced by 40 percent of college professors and 80 percent of middle/high school teachers. 4) What it calls attention in this study was to find that 96.5 percent of middle/high school teachers and 72 percent of college professors conduct population education to some extent during their lecture hours and that more than 80 percent of them are never experienced in teaching population and family planning contents in their regular classes. It is, on the other hand, found that no more than once was the response of those who believe themselves that they are experienced in teaching these relevant components to their students. Analyzing the contents of the subjects being taught in the class, a large percent of them are found to be consisted of population and family planning contents. According to this study, the current population education through the formal school is quite inactive. Analyzing the facts, 44.9 percent of the college professors responded that the population and family planning components are quite apart from their specialization which eventually generates lack of interest in the field. 5) It is also noticed through the study that the degree of frequency of commenting on population and family planning contents during the classes was depending significantly on their specializations which means that the degree of frequency varies from a major to another. Those who majored in home managerial science was the first one, as compared to others who majored in different specializations. Glancing over the status of correlations between ages of the respondents and numbers of seminar paticipation, it is quite clear that the aged group participated more than the younger group did, and that the most highest number of participations made by college professors were those who are in 50s. In addition, it is also found that those who are aged 20s and 60s of the respondents were the group who comments least on the contents of population and family planning at their classes. The suggestions and recommendation made through this survey research are as follows. 1) No one denies that the rapid increase of population, as compared to the limited size of land and resources, will certainly affect adversly to an enhancement of individual life quality which will, eventually, bring forth the poverty of the nation. This is the reasson why we are insisting that the world population be controlled up to an optimum level with a matter of global concerns. It is our understading that the primary aim for reducing number of population is believed to be attained only by conducting the systematic and comprehensive population education through the formal schools. Therefore, the role of home economists in the field of population/family planning education is considered very importment due to the fact that an ultimate goal of population education is placed in elevating the quality of family life by having optimum number of children through family planning program. 2) It is quite clear that home economists as teachers of formal school in all level are invited to pay their attention on redefining the ultimate goal of education and that of population education. We also understant that the primary objective of population education is to change the norm and value of the clients by replenishing the students with pertinent knowledge and attitudes on population and its related problems through a sort of education in order to attain the ultimate goal for enhancing the quality of life. There is no exception in the theory of home economics. An altimate goal of home economics is to elevate the general quality of life through an establishment of value existed in daily life. Considering the relations between population education and home economics, it is quite indespensable to bandle population components as an integral part in the field of home economics. We believe, therefore, that the senior home economists positive participation in the effort population control is more needed than it has been. 3) It is also strongly urged that population education should be a part of instructor training course for home economics. In other words, the teacher of home economics should be well aware of population and its problems by teaching interrelationship between population education and home economics, needs, contents and methods of population education during the instructor training courese for home economics. In addition, the senior home economists should be encouraged through positive participation on the short term training by types of domestic and international seminar, workshop, etc. 4) We certainly believe that the population education can not sustain itself without any backing-up of information and findings' of various and comprehensive researches of natural and social sciences. Accordingly, every senior home economist is invited to exert their maximum effort to conduct systematic study with an aim to utilize these findings and information at best in population education in the field of home economics. Therefore, we consider that the development of training material is imminent in order to provide effective and efficient population education through the for training of home economies. It should be noted that these training materials must be carefully designed, tailored and developed to meet the different classes of trainees under the considerations as to whether it is easily adaptable and infusable into the curricula of every field of home economics, and it is acceptable in the degree of difficulty and quality in its contents. 5) It is true that there are many domestic and international research rapers, reports and findings in the field of population education and family planning. However, there is a tendency that the most of research papers are heavily relying on the authors intension and preferences in its expression and publication. Under these circumstances, it is urged that the home economists should aware of the growing need of the technical training in order to keep these available information and research findings reprocessed and redesigned to insure the practical application into the population education in the field of home economics in Korea.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.452-461
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• 1994

Background: Tumor necrosis factor(TNF)-$\alpha$ and Interleukin(lL)-$1{\beta}$ are thought to play a major role in the pathogenesis of the septic syndrome, which is frequently associated with adult respiratory distress syndrome(ARDS). In spite of many reports for the role of TNF-$\alpha$ in the pathogenesis of ARDS, including human studies, it has been reported that TNF-$\alpha$ is not sensitive and specific marker for impending ARDS. But there is a possibility that the results were affected by the diversity of pathogenetic mechanisms leading to the ARDS because of various underlying disorders of the study group in the previous reports. The purpose of the present study was to evaluate the roles of TNF-$\alpha$ and IL-$1{\beta}$ as a predictable marker for development of ARDS in the patients with septic syndrome, in which the pathogenesis is believed to be mainly cytokine-mediated. Methods: Thirty-six patients of the septic syndrome hospitalized in the intensive care units of the Asan Medical Center were studied. Sixteens suffered from ARDS, whereas the remaining 20 were at the risk of developing ARDS(acute hypoxemic respiratory failure, AHRF). In all patients venous blood samples were collected in heparin-coated tubes at the time of enrollment, at 24 and 72 h thereafter. TNF-$\alpha$ and IL-$1{\beta}$ was measured by an enzyme-linked immunosorbent assay (ELISA). All data are expressed as median with interquartile range. Results: 1) Plama TNF-$\alpha$ levels: Plasma TNF-$\beta$ levels were less than 10pg/mL, which is lowest detection value of the kit used in this study within the range of the $mean{\pm}2SD$, in all of the normal controls, 8 of 16 subjects of ARDS and in 8 in 20 subjects of AHRF. Plasma TNF-$\alpha$ levels from patients with ARDS were 10.26pg/mL(median; <10-16.99pg/mL, interquartile range) and not different from those of patients at AHRF(10.82, <10-20.38pg/mL). There was also no significant difference between pre-ARDS(<10, <10-15.32pg/mL) and ARDS(<10, <10-10.22pg/mL). TNF-$\alpha$ levels were significantly greater in the patients with shock than the patients without shock(12.53pg/mL vs. <10pg/mL) (p<0.01). There was no statistical significance between survivors(<10, <10-12.92pg/mL) and nonsurvivors(11.80, <10-20.8pg/mL) (P=0.28) in the plasma TNF-$\alpha$ levels. 2) Plasma IL-$1{\beta}$ levels: Plasma IL-$1{\beta}$ levels were less than 0.3ng/mL, which is the lowest detection value of the kit used in this study, in one of each patients group. There was no significant difference in IL-$1{\beta}$ levels of the ARDS(2.22, 1.37-8.01ng/mL) and of the AHRF(2.13, 0.83-5.29ng/mL). There was also no significant difference between pre-ARDS(2.53, <0.3-8.34ngfmL) and ARDS(5.35, 0.66-11.51ng/mL), and between patients with septic shock and patients without shock (2.51, 1.28-8.34 vs 1.46, 0.15-2.13ng/mL). Plasma IL-$1{\beta}$ levels were significantly different between survivors(1.37, 0.4-2.36ng/mL) and nonsurvivors(2.84, 1.46-8.34ng/mL). Conclusion: Plasma TNF-$\alpha$ and IL-$1{\beta}$ level are not a predictable marker for development of ARDS. But TNF-$\alpha$ is a marker for shock in septic syndrome. These result could not exclude a possibility of pathophysiologic roles of TNF-$\alpha$ and IL-$1{\beta}$ in acute lung injury because these cytokine could be locally produced and exert its effects within the lungs.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.555-568
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• 1995

Background: It is most physiologic to measure the diffusing capacity of the lung by using oxygen, but it is so difficult to measure partial pressure of oxygen in the capillary blood of the lung that in clinical practice it is measured by using carbon monoxide, and single-breath diffusing capacity method is used most widely. However, since the process of withholding the breath for 10 seconds after inspiration to the total lung capacity is very hard to practice for patients who suffer from cough, dyspnea, etc, the intra-breath lung diffusing capacity method which requires a single exhalation of low-flow rate without such process was devised. In this study, we want to know whether or not there is any significant difference in the diffusing capacity of the lung measured by the single-breath and intra-breath methods, and if any, which factors have any influence. Methods: We chose randomly 73 persons without regarding specific disease, and after conducting 3 times the flow-volume curve test, we selected forced vital capacity(FVC), percent of predicted forced vital capacity, forced expiratory volume within 1 second($FEV_1$), percent of forced expiratory volume within 1 second, the ratio of forced expiratory volume within 1 second against forced vital capacity($FEV_1$/FVC) in test which the sum of FVC and $FEV_1$ is biggest. We measured the diffusing capacity of the lung 3 times in each of the single-breath and intra-breath methods at intervals of 5 minutes, and we evaluated which factors have any influence on the difference of the diffusing capacity of the lung between two methods[the mean values(ml/min/mmHg) of difference between two diffusing capacity measured by two methods] by means of the linear regression method, and obtained the following results: Results: 1) Intra-test reproducibility in the single-breath and intra-breath methods was excellent. 2) There was in general a good correlation between the diffusing capacity of the lung measured by a single-breath method and that measured by the intra-breath method, but there was a significant difference between values measured by both methods($1.01{\pm}0.35ml/min/mmHg$, p<0.01) 3) The difference between the diffusing capacity of the lung measured by both methods was not correlated to FVC, but was correlated to $FEV_1$, percent of $FEV_1$, $FEV_1$/FVC and the gradient of methane concentration which is an indicator of distribution of ventilation, and it was found as a result of the multiple regression test, that the effect of $FEV_1$/FVC was most strong(r=-0.4725, p<0.01) 4) In a graphic view of the difference of diffusing capacity measured by single-breath and intra-breath method and $FEV_1$/FVC, it was found that the former was divided into two groups in section where $FEV_1$/FVC is 50~60%, and that there was no significant difference between two methods in the section where $FEV_1$/FVC is equal or more than 60% ($0.05{\pm}0.24ml/min/mmHg$, p>0.1), but there was significant difference in the section, less than 60%($-4.5{\pm}0.34ml/min/mmHg$, p<0.01). 5. The diffusing capacity of the lung measured by the single-breath and intra-breath method was the same in value($24.3{\pm}0.68ml/min/mmHg$) within the normal range(2%/L) of the methane gas gradient, and there was no difference depending on the measuring method, but if the methane concentration gradients exceed 2%/L, the diffusing capacity of the lung measured by single-breath method became $15.0{\pm}0.44ml/min/mmHg$, and that measured by intra-breath method, $11.9{\pm}0.51ml/min/mmHg$, and there was a significant difference between them(p<0.01). Conclusion: Therefore, in case where $FEV_1$/FVC was less than 60%, the diffusing capacity of the lung measured by intra-breath method represented significantly lower value than that by single-breath method, and it was presumed to be caused largely by a defect of ventilation-distribution, but the possibility could not be excluded that the diffusing capacity of the lung might be overestimated in the single-breath method, or the actual reduction of the diffusing capacity of the lung appeared more sensitively in the intra-breath method.