• Title/Summary/Keyword: 1990′s

Search Result 6,060, Processing Time 0.035 seconds

Contents Analyses of Housing Educational research in Home Economics of Secondary School (중등학교 주생활교육 관련연구 내용분석)

  • Park, Mi-Jin;Yu, In-Young;Lim, Il-Young;Lee, Jong-Hee;Cho, Jae-Soon
    • Journal of Korean Home Economics Education Association
    • /
    • v.19 no.2
    • /
    • pp.35-49
    • /
    • 2007
  • The purpose of this research was to analyze the contents of Housing Studies in Home Economics Education of Secondary School published in master's or doctorial theses and journals since 1985. The 24 research papers were analyzed by the type and time of publication, research subjects, data collecting methods, respondents & sample size, and statistical methods. The data were presented by tables with frequencies. The results showed that the most Housing educational research has been done as a type of theses and the number of published papers on Housing has been increased in somewhat. Over time there were two main theme of Housing educational research: general perception of housing and teaching - learning plans. Research methods, respondents and sample size, and statistical methods were obviously differed by the two research theme of Housing educational studies. This research suggested to broaden the research subjects as well as research methods beside to increase the number of studies on Housing area in Home Economics Education.

  • PDF

Optimal Selection of Classifier Ensemble Using Genetic Algorithms (유전자 알고리즘을 이용한 분류자 앙상블의 최적 선택)

  • Kim, Myung-Jong
    • Journal of Intelligence and Information Systems
    • /
    • v.16 no.4
    • /
    • pp.99-112
    • /
    • 2010
  • Ensemble learning is a method for improving the performance of classification and prediction algorithms. It is a method for finding a highly accurateclassifier on the training set by constructing and combining an ensemble of weak classifiers, each of which needs only to be moderately accurate on the training set. Ensemble learning has received considerable attention from machine learning and artificial intelligence fields because of its remarkable performance improvement and flexible integration with the traditional learning algorithms such as decision tree (DT), neural networks (NN), and SVM, etc. In those researches, all of DT ensemble studies have demonstrated impressive improvements in the generalization behavior of DT, while NN and SVM ensemble studies have not shown remarkable performance as shown in DT ensembles. Recently, several works have reported that the performance of ensemble can be degraded where multiple classifiers of an ensemble are highly correlated with, and thereby result in multicollinearity problem, which leads to performance degradation of the ensemble. They have also proposed the differentiated learning strategies to cope with performance degradation problem. Hansen and Salamon (1990) insisted that it is necessary and sufficient for the performance enhancement of an ensemble that the ensemble should contain diverse classifiers. Breiman (1996) explored that ensemble learning can increase the performance of unstable learning algorithms, but does not show remarkable performance improvement on stable learning algorithms. Unstable learning algorithms such as decision tree learners are sensitive to the change of the training data, and thus small changes in the training data can yield large changes in the generated classifiers. Therefore, ensemble with unstable learning algorithms can guarantee some diversity among the classifiers. To the contrary, stable learning algorithms such as NN and SVM generate similar classifiers in spite of small changes of the training data, and thus the correlation among the resulting classifiers is very high. This high correlation results in multicollinearity problem, which leads to performance degradation of the ensemble. Kim,s work (2009) showedthe performance comparison in bankruptcy prediction on Korea firms using tradition prediction algorithms such as NN, DT, and SVM. It reports that stable learning algorithms such as NN and SVM have higher predictability than the unstable DT. Meanwhile, with respect to their ensemble learning, DT ensemble shows the more improved performance than NN and SVM ensemble. Further analysis with variance inflation factor (VIF) analysis empirically proves that performance degradation of ensemble is due to multicollinearity problem. It also proposes that optimization of ensemble is needed to cope with such a problem. This paper proposes a hybrid system for coverage optimization of NN ensemble (CO-NN) in order to improve the performance of NN ensemble. Coverage optimization is a technique of choosing a sub-ensemble from an original ensemble to guarantee the diversity of classifiers in coverage optimization process. CO-NN uses GA which has been widely used for various optimization problems to deal with the coverage optimization problem. The GA chromosomes for the coverage optimization are encoded into binary strings, each bit of which indicates individual classifier. The fitness function is defined as maximization of error reduction and a constraint of variance inflation factor (VIF), which is one of the generally used methods to measure multicollinearity, is added to insure the diversity of classifiers by removing high correlation among the classifiers. We use Microsoft Excel and the GAs software package called Evolver. Experiments on company failure prediction have shown that CO-NN is effectively applied in the stable performance enhancement of NNensembles through the choice of classifiers by considering the correlations of the ensemble. The classifiers which have the potential multicollinearity problem are removed by the coverage optimization process of CO-NN and thereby CO-NN has shown higher performance than a single NN classifier and NN ensemble at 1% significance level, and DT ensemble at 5% significance level. However, there remain further research issues. First, decision optimization process to find optimal combination function should be considered in further research. Secondly, various learning strategies to deal with data noise should be introduced in more advanced further researches in the future.

The Price Dynamics in Futures and Option Markets - based on KOSPI200 stock index market - (주가지수선물가격과 옵션가격의 동적관련성에 관한 연구 - KOSPI 200 주가지수현물시장을 중심으로 -)

  • Seo, Sang-Gu
    • Management & Information Systems Review
    • /
    • v.36 no.3
    • /
    • pp.37-49
    • /
    • 2017
  • This study investigates the dynamic relationship between KOSPI200 stock index and stock index futures and stock index option markets which is its derived from KOSPI200 stock index. We use 5-minutes rate of return data from 2012. 06 to 2014. 12. To empirical analysis, this study use autocorrelation and cross-correlation analysis as a preliminary analysis and then following Stoll and Whaley(1990) and Chan(1992), the multiple regression is estimated to examine the lead-lag patterns between the stock index and stock index futures and option markets by Newey and West's(1987) Empirical results of our study shows as follows. First, there exist a strong autocorrelation in the KOSPI200 stock index before 10minutes but a very weak autocorrelation in the stock index futures and option markets. Second, there is a strong evidence that stock index future and option markets lead KOSPI200 stock index in the cross-correlation analysis. Third, based on the multiple regression, the stock index futures and option markets lead the stock index prior to 10-15 minutes and weak evidence that the stock index leads the future and option markets. This results show that the market efficient of KOSPI200 stock index market is improved as compared to the early stage of stock index future and option market.

  • PDF

Clinical Investigation of Cervical Tuberculous Lymphadenitis (결핵성 경부 임파선염의 임상적 고찰)

  • Park, Mi-Ran;Kim, Chang-Sun;Seo, Jee-Young;Son, Hyung-Dae;Rheu, Nam-Soo;Cho, Dong-Il
    • Tuberculosis and Respiratory Diseases
    • /
    • v.44 no.6
    • /
    • pp.1225-1233
    • /
    • 1997
  • Background : Cervical tuberculous lymphadenitis(CTL) is one of the most common extra-pulmonary tuberculosis. Recently overall incidence of pulmonary tuberculosis has decreased, but the incidence of tuberculous lymphadenitis has not decreased. Its duration of treatment is still controversial and the pathogenesis, prognosis and relationship with other site tuberculous are poorly published. So we did a retrograde study of 120 cases of confirmed CTL about its clinical manifestations. Method : All patients were applied fine needle aspiration(FNA) of palpable enlarged cervical lymph nodes and 114 patients were examined for AFB smear and 34 patients for TB culture with aspirated fluid. 57 patients were examined Mantoux test(5TU with PPD-S). With above methods, a total of 120 patients was diagnosed as having CTL. Results : 1) CTL is most prevalent in young women between the age of 20~30 years and the incidence of CTL in female is 2.5 times higher than that of male. It is located most commonly in the posterior cervical area. The most common presenting symptom is painless palpable enlarged cervical lymph nodes. 2) With FNA of enlarged cervical lymph nodes, the percentage of histopathological positivity is 82.3%. The percentage of AFB smear positivity is 38.6%, and that of TB culture positivity is 17.6%(p<0.001). 3) Pulmonary tuberculosis is noted in 79 cases(65.8%). And 42 cases(53.5%) of them had minimal pulmonary tuberculosis. In 14 cases(11.7%), other extrapulmonary tuberculosis coexsisted and pleural tuberculosis was most Common in the order. 4) CTL was treated with anti-tuberculous medication(first line drug) and median treatment duration was 18.5months. During treatment, the size of involved lymph nodes decreased gradually in 62 cases(75.8%), newly developed lymph nodes were found in 25 cases(30.4%), fluctuation formation in 22 cases(26.8%) and fistula formation in 14 cases(17.0%). Conclusion : CTL is prevalent in women between the age of 20~40 years and it involves posterior cervical area most commonly. CTL is treated with long-term anti-tuberculous chemotherapy. We think it is one manifestation of systemic disease and frequently coexisting with pulmonary tuberculosis. Despite anti-tuberculous chemotherapy, the size of involved lymph nodes was increased, new lymph nodes were developed or fluctuation and fistula formed in involved lymph nodes. After sufficient medication, when the patient felt pressure discomfort from enlarged lymph node or fistula was formed, we recommended total excision of involved lymph nodes.

  • PDF

Long-term Variation and Characteristics of Water Quality in the Yeoja Bay of South Sea, Korea (여자만 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Kim, Sang-Soo;Kim, Pyoung-Joong;Cho, Eun-Seob;Kim, Byong-Man;Jeon, Sang-Baek;Jang, Su-Jeng
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.17 no.3
    • /
    • pp.203-218
    • /
    • 2011
  • Long-term trends and distribution patterns of water quality were investigated in the Yeoja Bay of South Sea, Korea from 1976 to 2010. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, hydrogen ion concentration (pH), dissolved oxygen (DO), chemical oxygen demand (COD), suspended solids (SS) and nutrients. Spatial distribution patterns of temperature, pH and DO were not clear among stations but the seasonal variations were distinct except ammonium. The trend analysis by principal component analysis (PCA) during 31 years revealed the significant variations in water quality in the study area. Spatial water qualities were discriminated into 2 clusters by PCA; station cluster 1 and 2~3. Annual water qualities were clearly discriminated into 4 clusters by PCA. By this multi-variate analysis, the annual trends were summarized as the followings; water temperature, COD and SS tended to increase from late 1970's, decreased salinity, and increased phosphate from 1991 to 2001 and increased dissolved inorganic nitrogen. Water quality was showed by the input of fresh water same as those of Kyoungin coastal area, Asan coastal area, Choensoo bay, Gunsan coastal and Mokpo coastal area in the Yeoja Bay.

Transformation is Mechanism of Gene Transfer in Soil (토양에서 Transformation에 의한 유전자 전이)

  • ;Stotzky, G.
    • Korean Journal of Microbiology
    • /
    • v.28 no.3
    • /
    • pp.210-218
    • /
    • 1990
  • The survival and transfer of chromosomal genes coding for the synthesis of amino acids (threonine, tryptophan, histidine, leucine, methionine) and of plasmid-borne genes coding for resistance to antibiotics (chloramphenicol, kanamycin, erythromycin) by transformation in sterile and nonsterile soil (the soil was amended to 12% vol/vol with the clay mineral, montmorillonite) was studied. In pure culture, the numbers of vegetative cells of the Bacillus subtilis strains decreased by 1 to 1.5 orders of magnitude within one week, but spores of each strain showed lesser decreases. In sterile soil, the populations of vegetative cells and spores decreased by 1.5 to 3 orders of magnitude within 2 to 4 days and then showed little additional decreased. The transformation frequencies (number of transformants/numbers of donors and recipients) of individual amino acid-genes invitro ranged from $1.3{\pm}0.6{\times}10^{-6}$ to $6.0{\pm}2.36{\times}10^{-6}$, of two amino acid-genes from $8.5{\pm}0.7{\times}10^{-8}$ to $3.1{\pm}0.6{\times}10^{-7}$, and of the antibiotic-resistance genes from $1.5{\pm} 0.2{\itmes} 10^{-7}$ to $1.4{\pm} 0.4{\times} 10^{-5}$ . In sterile soil, the frequencies of transfer of individual amino acid-genes ranged from $2.0{\times} 10^{-7}$ to $2.0{\times} 10^{-5}$ and of the antibiotic-resistance genes from $2.0{\times} 10^{-7}$ to $9.4{\pm} 4.7{\times} 10^{-6}$. The transfer of two amino acid-genes in sterile soil was detected at a frequency of $2.0{\times} 10^{-6}$ to $4.5{\times} 10^{-6}$, but only in three instances. The transformation frequencies of antibiotic-resistance genes in nonsterile soil were essentially similar to those in sterile soil. However, to detect transformants in nonsterile soil, higher concentrations of antibiotics were needed, as the result of the large numbers of indigenous soil bacteria resistant to the concentration of antibiotics used in the sterile soil and in vitro studies. The results of these studies show that genes can be transferred by transformation in soil and that this mechanism of transfer must be considered in risk assessment of the release of genetically engineered microorganisms to the environment.

  • PDF

A Study on Correlation between El-Nino and Winter Temperature and Precipitation in Korea (엘니뇨와 한국의 겨울 기온 및 강수량과의 상관에 관한 연구)

  • Min, Woo-Ki;Yang, Jin-Suk
    • Journal of the Korean association of regional geographers
    • /
    • v.4 no.2
    • /
    • pp.151-164
    • /
    • 1998
  • I analyzed the correlation between El-Nino phenomenon and our country's temperature and precipitation laying the stress on the anomaly, and the result of this analysis is as follows: (1) The extraction of the occurrences of El-Nino at the place of sea surface around Nino.3 which was known as the sea area under observation for El-Nino reveals that there are 9 years (1969, 1970, 1973, 1977, 1987, 1992, 1995, 1998) when the temperature anomaly in January is more than 1.0 during the period of research years ($1969{\sim}1998$). (2) The tendency of change of sea surface temperature around Nino.3 and that of our country are about the same, but the anomaly of Pusan and Inchon was much greater than that of Jangki in the East Coast. (3) The anomaly of sea surface temperature around Nino.3 and that of the ground temperature showed the similar changing tendency, the temperature of our country has something to do with that of sea surface as the correlation of ground temperature with the temperature of sea surface showed 0.31. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomenon appeared. (4) As for the precipitation, we can see that it has generally increased after 1989 when the phenomenon of warm climate was intense than before that year. But as we study the change of anomaly, the precipitation has less correlation in comparison with the ground temperature. The precipitation in 1973, 1983 and 1987 which were El-Nino years was correlated with El-Nino. While the change of sea surface temperature has showed a tendency of plus(+)increase since 1990, the precipitation has showed a tendency of minus (-)decrease. Therefore it seems that the temperature of sea surface has little correlation with the amount of rainfall.

  • PDF

Nursing research issues and trends : views from Korea (우리나라 간호연구의 현황과 문제)

  • Oh, Kasil;Sin, Hee-Sun;Kim, Hee-Soon
    • The Korean Nurse
    • /
    • v.31 no.3
    • /
    • pp.76-87
    • /
    • 1992
  • The purposes of study was: 1. To identify the direction and scope of research activities in Korean Nursing. 2. To discuss the unique problems present in Korea that warrant nursing research. 3. To delineate the factors that facilitate and/or hinder nursing research in Korea. This study was conducted at six colleges of nursing in Korea. The schools which were selected had doctoral programs at the time, the data were collected in 1990. Four of the schools were located in the metropolitan area of the capital city, Seoul, and two were in two other cities similar in size. The total population of the study was 283 nurses. The instrument for the research was the English version of Research Profile Questionnaire which was translated into Korean by the researchers and was validated in its translation by two professors. A pretest procedure was done before the data collection process. Of the population of 283, 210 subjects received the questionnaire and 150 subjects responded(71.4%). Excluding incomplete questionnaires, 141 questionnaires were utilized for data analysis. Data were analyzed using descriptive statistics. Responses to open-ended questions were content analyzed for themes and categories. Results of the study were as follows : Respondents currently , involved in nursing research numbered 108(76.6%), but 33(23.4%) did not have any research experience. The inexperienced respondenLs tended to be younger than the experienced subjects and most( 60.6%) were employed in hospitals, while 82.4 percent of the experienced nurses were employed in nursing schools. Among the respondents with research experience, 68.5 percent were involved in one to three projects and 31.5 percent were engaged in four or more projects. The experienced nurses indicated that nursing research in Korea is active. On the other hand, the responses of the inexperienced were that nursing research is not active. The most frequently selected research subjects were patients(76.9%, 83 respondents) followed by nurses, healthy persons and nursing students. The relatively high percentage of healthy persons as study subjects, could be explained as a concern of nurses for healthy persons as well as for ill patients. The aforememioned literature review showed a dramatic change in the kinds of study subjects; approximately 33 percent were patients but 25 percent were healthy subjects of various ages. The hospital was the prevailing research setting(67.6%) but at the same time various community settings were used. This is a changing phenomena in nursing research of Korea. Current research designed to build on previous studies amounted to 75 percent; about 39.8 percem were theory and hypothesis generated. Over 65 recommended additional research focusing on hypothesis-testing 0:' theory building. The previously quoted literature review found that only 4.0 percent of the study quescions were developed from a theoretical framework. The most frequently listed current major focus of nursmg research was stress and adaptation. Patients with cancer, pain, social support and care of the elderly were the next most frequently reported. These concerns may reflect problems associated with a technological and industrializing societyl. The most frequently identified problem was lack of clinical research. The need for replication research and research that contributes to the accumulation of nursing knowledge were found to be rare in Korean research. A need for theory testing and theory construction research was also identified. Although advanced statistical methods were often utilized in nursing research, the results were frequently considered by the interviewers not to be applicable in practice, and readers had difficulty in comprehending the findings. Even though the number of clinical nurses involved in research is increasing, it is still considered inadequate. Among 108 respondents, 83(76.9%) gave lack of time as a barrier to conducting nursing research. Over fifty percent of the respondents reported lack of funding or, personally, low confidence in research skills as barriers. The respondents offered 183 suggestions for future emphasis in nursing research. Among the 51 areas of emphasis, clinical research received the highest number and nursing intervention was next. The findings suggested that nursing research should be based on theory, be related to practice and relevant to the situation of a unique Korean culture.

  • PDF

A Study of Chinese Translation and Reader Reception of the Modern Korean Novel, Focusing on the Last 5 Years (한국현대소설의 중국어번역현황 및 독자수용양상 고찰 - 최근 5년간을 중심으로)

  • Choi, Eun-Jeong
    • Cross-Cultural Studies
    • /
    • v.43
    • /
    • pp.429-457
    • /
    • 2016
  • This article is an analysis of the status of the modern Korean novels translated into Chinese over the past five years and how they are perceived by readers. Translation of modern Korean novels over the past five years has a few important characteristics as the following. The first characteristic is diversity. Books written by the most representative modern Korean writers, like Lee Gwang-soo, Kim Yu-jung, Kim Dong-ri, and books of the authors with very unique ideas, such as Park Kyung-ri, Lee Mun-yeol, Shin Kyung-suk, Gong Ji-young, Kim Young-ha, Park Min-kyu, Cheon Myung-gwan, and Kim Ae-ran have been translated and introduced to the Chinese population. Secondly, there are active translation of the books written by female writers. Lastly, without the support of the Literature Translation Institute of Korea or the Daesan Foundation, the number of works translated and published is slowly increasing. As a result of the increasing number of translations, the quality of translation is improving. However, interest on the part of Chinese readers in the modern Korean novel is not very high. But, the works of authors like Kim Young-ha, Cheon Myung-gwan, Kim Ae-ran, and Park Min-kyu, who began their literary careers after the mid-90s, are drawing relatively more attention. The common features of such works are the novelty of the narrative methods, attachment to reality, and readability. The interest shown by Chinese readers is significant in explaining the two following factors. First, it is true that many modern Korean novels are available in China, but only those that have been read will continue to be read. Second, the indifference of Chinese readers to modern Korean novels is because they are not yet aware of the existence of such works. It is important to train professional translators who can properly translate literature and also to focus on introducing the differences in modern Korean novels through canonical translation. To achieve this aim, not only supportive policies, but also cooperation between researchers in the field of modern Korean literature, translators, and publishers is essential.

Vietnam in 2016: The Situations and Prospects of Politics, Economy, and International Relations (베트남 2016: 정치, 경제, 대외관계의 현황과 전망)

  • LEE, Han Woo;CHAE, Su Hong
    • The Southeast Asian review
    • /
    • v.27 no.1
    • /
    • pp.163-191
    • /
    • 2017
  • This article aims to review the recent, especially focusing on the year of 2016, situations and prospects of the Vietnamese politics, economy, and international relations. Politically, Vietnam completed the election of members for the National Assembly and organized new leadership at the 12th National Congress of the Vietnamese Communist Party in 2016. One characteristic of the new leadership is that the politicians, especially the members of politburo, from the North continue to occupy the position of majority. The other one is that the new leadership promised to carry out the restructuring of economy toward industries producing higher value-added commodities even though Vietnam industries admittedly need to accelerate present industrialization and modernization as a developing country under the seemingly contradictory slogan of "the development of market economy for socialism." The declared goals of the new leadership in Vietnam are inevitable in a sense since the development of Vietnamese economy has been heavily dependent upon Foreign Direct Investment(FDI) taking advantage of Vietnamese cheap labor and simultaneously it is evident that its future is unsecure if it maintains status quo. In fact, the Vietnamese economy has impressively showed high growth rate by the help of foreign capitals since 1990s despite the repetitive recessions of global economy but its growth is not likely to be sustainable anymore if it will not reduce foreign dependency and social economic inequality in a long term. In a short run, global economic recession, the financial and monetary policies of global powers, and recent protectionism and uncertainty of trade agreements will be three crucial variables to affect Vietnamese economy. In terms of international relations, Vietnam is continuously expected to practise the policy of checks and balances among the powerful countries. Vietnam has seriously disputed with China on islands sovereignty in the South China Sea and attempted to maintain close relationship with other powerful countries including especially America. However, mainly due to the new protectionism by the regime of American president Donald Trump, the Vietnamese government also need to keep close relationship with China increasingly for both economic and diplomatic security. Under the circumstances, Vietnam is expected to maintain more practical and balanced international relations.