• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.271-280
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• 1999

인공신경망을 시계열예측에 적용하는 경우에 고려되어야 할 문제중, 특히 모형에 적합한 입력변수의 생성이 중요시되고 있는데, 이러한 분야는 인공신경망의 모형생성과정에서 입력변수에 대한 전처리기법으로써 다양하게 제시되어 왔다. 가장 최근의 입력변수 전처리기법으로써 제시되고 있는 신호처리기법은 전통적 주기분할처리방법인 푸리에변환기법(Fourier transforms)을 비롯하여 이를 확장시킨 개념인 웨이블릿변환기법(wavelet transforms) 등으로 대별될 수 있다. 이는 기본적으로 시계열이 다수의 주기(cycle)들로 구성된 상이한 시계열들의 집합이라는 가정에서 출발하고 있다. 전통적으로 이러한 시계열은 전기 또는 전자공학에서 주파수영역분할, 즉 고주파 및 저주파수를 분할하기 위한 기법에 적용되어 왔다. 그러나, 최근에는 이러한 연구가 다양한 분야에 활발하게 응용되기 시작하였으며, 그 중의 대표적인 예가 바로 경영분야의 재무시계열에 대한 분석이다 전통적으로 재무시계열은 장, 단기의사결정을 가진 시장참여자들간의 거래특성이 시계열에 각기 달리 가격으로 반영되기 때문에 이러한 상이한 집단들의 고유한 거래움직임으로 말미암아 예를 들어, 주식시장이 프랙탈구조를 가지고 있다고 보기도 한다. 이처럼 재무시계열은 다양한 사회현상의 집합체라고 볼 수 있으며, 그만큼 예측모형을 구축하는데 어려움이 따른다. 본 연구는 이러한 시계열의 주기적 특성에 기반을 둔 신호처리분석으로서 기존의 시계열로부터 노이즈를 줄여 주면서 보다 의미 있는 정보로 변환시켜 줄 수 있는 웨이블릿분석 방법론을 새로운 필터링기법으로 사용하여 현재 많은 연구가 진행되고 있는 인공신경망과의 모형결합을 통해 기존연구와는 다른 새로운 통합예측방법론을 제시하고자 한다. 본 연구에서 제시하는 통합방법론은 크게 2단계 과정을 거쳐 예측모형으로 완성이 된다. 즉, 1차 모형단계에서 원시 재무시계열은 먼저 웨이블릿분석을 통해서 노이즈가 필터링 되는 동시에, 과거 재무시계열의 프랙탈 구조, 즉 비선형적인 움직임을 보다 잘 반영시켜 주는 다차원 주기요소를 가지는 시계열로 분해, 생성되며, 이렇게 주기에 따라 장단기로 분할된 시계열들은 2차 모형단계에서 신경망의 새로운 입력변수로서 사용되어 최종적인 인공 신경망모델을 구축하는 데 반영된다.

• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.84-97
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• 1983

Under the limited arable land, the enhancement of agricultural productivity is indispensable to provide the food demand which is concomitant with the rapid increase in population. From this viewpoint, the upbringing and dissemination of high-yielding varieties has been promoted continuously and several modifications in cultural practices, including heavy fertilization, dense planting, and early transplanting, also have been gradually developed. However these changes in cultivation have led to the increased outbreak of insect pests and diseases. And this unexpected results have accelerated the number and complexity of pesticides employed as well as their consumption. Even though pesticides are essential materials contributing to the steady production of agricultural crops, large scale consumption of them has given rise to several adverse impacts, such as mammalian hazard and/or environmental contamination. In this respect, recent development of new pesticides has been concentrated on 'safe pesticide', as it were, that has the highly selective properties without unfavorable side influences on other ecosystem. According to literature cited up to now, feasibilities of safe pesticide development would be summarized as two categories. One of them is the development of chemical pesticides, which include the molecular structure modification of established pesticides for increased safety and synthesis of new safe chemicals which can attack the vulnerable point of physio-ecological characteristics in insect pests and diseases. The other is the biological pesticides which comprise natural enemies and microorganisms to act selectively on confined insect pests and diseases, In addition, improvement of physico-chemical properties of available pesticide formulations would be one of the desirable means for safe pesticide development in view of efficacy enhancement and minimization of hazardous properties or safe pesticide development, various approaches are feasible and needed to study, however, long period and much financial outlay are necessary to develop a new item. And under the present situation in Korea, there are many difficulties for performing research on all the possible routes. Therefore, combined pesticides by the reasonable combination of already registered resticides evaluated as the fairly safe pesticides and safe formulation based on their physico-chemical properties would be developed primarily. And many efforts would be given gradually for the development of new chemical and biological pesticides.

• Korean journal of communication and information
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• v.19
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• pp.239-264
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• 2002

The networking between the press and elites, and its impact on journalistic activities in fact have been major subjects of scholarly scrutiny particularly among students of elite theory and class theory. This is an empirical analysis of how the press establishes networks with several powers in local community. This study basically examines a set of independent variables, such as the nature of capital and history of local newspapers and explores how the management and elites in the press utilize several social resources and establish networks. Major findings of this study are as follows: To begin with, the networking between local newspapers and elites showes significant differences according to the nature of capital and history of the newspaper. In other words, while the newspapers operated by stock capital revealed high degree of networking with political and financial elites, the newspapers operated by family capital did not demonstrate significant level of networking with particular elites. The shorter the history of newspaper is, the more she tends to be dependent on resources, and feel it imperative to establish strong networks with elites.

• Journal of Information Technology Applications and Management
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• v.22 no.3
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• pp.65-81
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• 2015

This study reports a preliminary finding of the types and numbers of graphs being presented in the annual reports of about thirty top listed companies trading publicly in the stock markets of three countries-Thailand (SET), Malaysia (BM), and Singapore (SGX)-that were chosen based on their inclusion in the ASEAN Stars Index under the ASEAN Trading Link project. A total of 6,753 graphs from nineteen sectors were extracted and examined. Banking, real estate, and telecommunications are ranked the three most condense sectors, accounting for 50.2% of the total number of graphs observed. The three most used graphs are the Conservative Bar, Donut graph and Stack Bar. Less than one percent of Infographic type graphs were used. The five most depicted graphed variables are Asset, Revenue, Net profit, Liability, and Dividend. Using rudimentary framework to detect distorted or misleading statistical graphs, the study found 60.6% of the graphs distorted across the three markets, SET, BM, and SGX. BM ranked first in percentages of graphs being distortedly presented (73%). The other two markets, SET and SGX, have about the same proportions, 53.88% and 53.03%, respectively. Likewise, the proportions of Well-designed versus Inappropriate-designed graphs of the latter two markets are a little over one time (SET = 1 : 1.17; SGX = 1 : 1.13), whereas the proportion is almost triple for the BM market (BM = 1 : 2.70). In addition, the trend of distorted graphs found is slightly increasing as the longevity of the ASEAN Stars Index increases. One possible explanation for the relatively equal proportion of inappropriate graphs found is that SET is the smallest market and SGX, though the largest, is the most regulated market. BM, on the other hand, may want to present their financial data in the most attractive manner to prospective investors, thus, regulatory constraints and governance structure are still lenient.

• Human Ecology Research
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• v.52 no.4
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• pp.355-369
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• 2014

The in-law relationship traditionally plays a major role in Korean marriages and families because parents-in-law prefer to stay with their son under the same roof. The recent spike in the number of intercultural matches in South Korea may be provoking changes in the traditional family experience. The object of this qualitative study was to explore the contextual factors causing conflicts between mothers-in-law and their daughters-in-law in multicultural families. Six mother and daughter in-law dyads from rural areas of South Korea were recruited and interviewed. We found that the mothers-in-law and daughters-in-law had had different motives for the marriage at first. Five major themes emerged from the analysis of the dyadic interviews: the conflicts of the participants were embedded in the alternative family formation, in financial strains and the power structure, barriers in communication, cultural insensitivity and conflicts between value systems, as well as in role conflicts due to differing role expectations and hegemony. In conclusion, the authors of this study suggest that increasing cultural sensitivity and communication skills in immigrant daughter-in-law an Korean mother-in-law relationships will be crucial for a healthy in-law relationship. The need for the availability of Multicultural Family Centers' services in the community was highlighted. In order for mothers-in-law and daughters-in-law to form positive relationships, it is important to facilitate a variety of easily accessible educational programs in the community focusing on fostering the mother-in-law's understanding of the daughter-in-law's perspective.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.14-25
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• 2009

Development work of apartment houses is a complex medium-and long-term project requiring grand resources and work force. Since in combination inner and outer project variables relate to project output, uncertainties caused by not only a given site condition but also politic, economy and social sectors are generated during the project. These risks influence output of the project as important factors, and ultimately as management variables in priority giving an effect on earnings and the financial structure of enterprises they should be manageable with the risk reduction plan. In this point of view, this study focused on development work of apartment houses among construction project. Risky factors were deduced, analyzed and evaluated based on Value Engineering from planning to designing to executing to maintaining. Eventually, this study showed the foundation guaranteeing competitive power of public and private construction sectors.

• Journal of the Korean Society of Food Culture
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• v.12 no.1
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• pp.87-96
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• 1997

The purpose of this study is, to examine current foodservice management practices at free meal service organization for elderly people and, to evaluate the attitude of recipients about the service and their ecological background. 6 meal service center as well as randomly selected 120 recipients at Sungnam area were surveyed and interviewed and result were summarized as follow. The cost of each meal (lunch) was ranged from 1,300 won to 1,500 won and number of attendant at meal service were ranged from 50 to 200 persons. Meal time for lunch begins from 10:30 am to noon because greater portion of people (elderly) didn't take breakfast frequently. Most of the center adapted self-service system. Standard recipe was not developed and meal preparation was controlled under the experiences of volunteer’s. Recording system of, nutrition management, production control, storage and inventory control was not well adapted by most of the center. In order to measure the level of storage, sanitation etc., scorin system in survey was adapted in this study and result are as follow: The score of sanitation of kitchen was lower than dinning area and that of food storage was lowest score. It was suggested that not only financial but also systematical support on management by local government may be necessary to meet the goal of supply nutritionally balanced food at the center. The score given by the recipient on the satisfaction of meal service was rate as 4.8 at the 5-point maximum scale. Meeting friends and share social relationship was major reason (41.6% of the total) of visiting to the center. It is suggested that in order to meet the changes of the patterns of change of social and family structure, the service of the center should be extended in urban area and it is necessary to develop systematic management models for the center.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.674-680
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• 2013

This paper investigates the impact of liquidity constraints on investment expenditures of family and non-family firms. We analyze the ownership structure of family firms to determine whether family control alleviates or exacerbates investment-cash flow sensitivity in domestic firms. To examine the impact of liquidity constraints on investment expenditures of family and non-family firms, we used a financial data of 644 Korea Exchange traded companies over the 2000 - 2010 period. We estimated a time-series and cross-sectional regression model, using samples of family firms and non-family firms. The results show that cash flow is not associated with investment expenditure in family firms, whereas cash flow has a positive impact on investment in non-family firms. Our results show that lower or no investment-cash flow sensitivities in family-controlled firms are mainly attributable to lower agency costs through strong monitoring activities of family members. Higher investment-cash flow sensitivities are observed in non-family firms with more agency problems. This suggests that investment-cash flow sensitivities would be useful measures of liquidity constraints.

• Journal of Intelligence and Information Systems
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• v.5 no.1
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• pp.103-123
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• 1999

Input filtering as a preprocessing method is so much crucial to get good performance in time series forecasting. There are a few preprocessing methods (i.e. ARMA outputs as time domain filters, and Fourier transform or wavelet transform as time-frequency domain filters) for handling time series. Specially, the time-frequency domain filters describe the fractal structure of financial markets better than the time domain filters due to theoretically additional frequency information. Therefore, we, first of all, try to describe and analyze specially some issues on the effectiveness of different filtering methods from viewpoint of the performance of a neural network based forecasting. And then we discuss about neural network model architecture issues, for example, what type of neural network learning architecture is selected for our time series forecasting, and what input size should be applied to a model. In this study an input selection problem is limited to a size selection of the lagged input variables. To solve this problem, we simulate on analyzing and comparing a few neural networks having different model architecture and also use an embedding dimension measure as chaotic time series analysis or nonlinear dynamic analysis to reduce the dimensionality (i.e. the size of time delayed input variables) of the models. Throughout our study, experiments for integration methods of joint time-frequency analysis and neural network techniques are applied to a case study of daily Korean won / U. S dollar exchange returns and finally we suggest an integration framework for future research from our experimental results.

• Journal of Korean Society of Rural Planning
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• v.22 no.3
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• pp.71-80
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• 2016

Korea is becoming a model country for the developing countries' agricultural and rural development. Drawing implications for Vietnam from Korea's experiences can help make development strategies and policies for other developing countries including North Korea as well as for Vietnam itself. Vietnam is facing an inefficiency in agricultural production and the gap between urban and rural growth has been widening. Farm sizes per household are small and farmlands are scattered. Diversification in rural industry is very restricted. To attack these problems, investment is urgently needed for rural infrastructure building as well as agricultural structure adjustment. In the process of rural development, there have been also encountered such problems as financial procurement, community's spontaneous participation, manpower development for adjusting to industrial structural change. Korea's experiences may be helpful for establishing rural development strategies and policies in Vietnam. Benchmark scopes can go beyond Saemaul Undong in 1970s. Korea's pre- and post-Saemaul Undong era as well as the Saemaul Undong era can be referred. In the wake of globalization, Vietnam has not only experienced compressed rapid economic growth but also encountered policy tasks to eradicate poverty, to realize self-reliance and income increase, and to lessen urban-rural development gap, at the same time. Korea's experiences show that priority needs to be put on the establishment of national and rural development strategies based on Vietnam-specific conditions, utilization of village's resources including community tradition and social capital, fund raising for rural development, farmland development and mobilization, production and living infrastructure building, technology transfer for farmers and vocational training for new job seekers.