• Journal of Korean Society of Transportation
• /
• v.25 no.3
• /
• pp.137-144
• /
• 2007

This study involves an analytical approach to determine transit dispatching schedules (headways) Determining a time schedule is an important process in transit system planning. In general, the transit headway should be shorter during the peak hour than at non-peak hours for demand-responsive service. It allows passengers to minimize their waiting time under inelastic, fixed demand conditions. The transit headway should be longer as operating costs increase, and shorter as demand and waiting time increase. Optimal headway depends on the amount of ridership. and each individual vehicle dispatching time depends on the distribution of the ridership. This study provides a theoretical foundation for the dispatching scheme consistent with common sense. Previous research suggested a dispatching scheme with even headway. However, according to this research, that is valid for a specific case when the demand pattern is uniform. This study is a general analysis expanding that previous research. This study suggests an easy method to set a time table without a complex and difficult calculation. Further. if the time axis is changed to the space axis instead, this study could be expanded to address the spacing problems of some facilities such as roads. stations, routes and others.

• Journal of Technology Innovation
• /
• v.18 no.2
• /
• pp.175-219
• /
• 2010

Since diversification can be a necessary means for company's survival and the conservation of its success, hundreds of studies have been done by three schools of industrial economics, strategic management, and Neo-Schumpeterian economics for over 30 years. However, any school has not presented a model comprehensively explaining diversification' success or failure. The study tried to suggest a theoretical framework integrating findings came from three schools. The framework considers both firm's technological capabilities and sector-specific characteristics as well as reflects a Neo-Schumpeterian view emphasizing technological aspects. The goal of the study is finding major reasons of success and failure during company's diversification through studying three diversification cases of Samsung. Our findings show that the diversification toward TFT-LCD was easier and more successful than the diversification toward microprocessor because DRAM is more similar to TFT-LCD than microprocessor. Samsung also tended to build only the types of capabilities which were originated from capabilities accumulated in DRAM business. Our findings give firm's strategists a lesson that they can increase the probability of success in diversification, if only they should simultaneously consider a new sector's characteristics, a firm's technological capabilities accumulated in old sectors, and the availability of old capabilities for being applied to a new sector.

• The Journal of Society for e-Business Studies
• /
• v.22 no.1
• /
• pp.15-35
• /
• 2017

The method of weighted sum of evaluation using AHP is widely used in feasibility analysis and alternative selection. Final scores are given in forms of weighted sums and the alternative with largest score is selected. With two alternatives, as in feasibility analysis, the final score greater than 0.5 gives the selection but there remains a question that how large is large enough. KDI suggested a concept of 'grey area' where scores are between 0.45 and 0.55 in which decisions are to be made with caution, but it lacks theoretical background. Statistical testing was introduced to answer the question in some studies. It was assumed some kinds of probability distribution, but did not give the validity on them. We examine the various cases of weighted sum of evaluation score and show why the statistical testing has to be introduced. We suggest a non-parametric testing procedure which does not assume a specific distribution. A case study is conducted to analyze the validity of our suggested testing procedure. We conclude our study with remarks on the implication of analysis and the future way of research development.

• Journal of Radiation Protection and Research
• /
• v.22 no.3
• /
• pp.161-170
• /
• 1997

Theoretical and experimental determination of the lower limits of detection (LLD) of C-300-A $CaSO_4$:Dy TL dosimeters which are currently used for the personnel monitoring in Korea Atomic Energy Research Institute(KAERI) are described with a critical level which is defined as the signal level above which a result has a probability of being due to a fluctuation of the background. The personnel monitoring processors can derived easily the LLD of their system using this method with the background readings of their service interval and the irradiation readings of the known doses. Experimental studies were also conducted for the fading rates of the dosimeters with the temperatures and humidities for 3 months. Finally sensitivity changes in repeat uses were measured for 40 times consecutive uses of the dosimeters. The applications of the experimental results of fading rates and sensitivity changes in real personnel monitoring services are discussed briefly.

• Composites Research
• /
• v.32 no.6
• /
• pp.327-334
• /
• 2019

The delamination is a special mode of failure occurring in composite laminates. Several numerical studies with finite element analysis have been carried out on the delamination behavior of unidirectional composite laminates. On the other hand, the fracture for the multi-directional composite laminates may occur not only along the resin-fiber interface between plies known as interply or interlaminar fracture but also within a ply known as interyarn or intralaminar fracture accompanied by matrix cracking and fiber bridging. In addition, interlaminar and intralaminar cracks appear at irregular proportions and intralaminar cracks proceeded at arbitrary angle. The probabilistic analysis method for the prediction of crack growth behavior within a layer is more advantageous than the deterministic analysis method. In this paper, we analyze the crack path when the mode I load is applied to the cross-ply carbon/epoxy composite laminates and collect and analyze the probability data to be used as the basis of the probabilistic analysis in the future. Two criteria for the theoretical analysis of the crack growth direction were proposed by analyzing the stress field at the crack tip of orthotropic materials. Using the proposed method, the crack growth directions of the cross-ply carbon/epoxy laminates were analyzed qualitatively and quantitatively and compared with experimental results.

• Korean Journal of Social Welfare
• /
• v.57 no.2
• /
• pp.375-403
• /
• 2005

This Study reviews theoretical argument about the effect of retirement earnings test on the labor supply of the aged which is controversial issue in OECD countries and analyze the effect on the incidence of re-employment, re-employment period of suspended officials and the possibility of re-retirement through Government Employment Pension Corporation data. It consists of 178,363 public officials who received pension benefit or disability pension in January 2005. The main result of this research shows that public officials re-employed were 8,086 which is 4.5% of total retired, and median survival time of suspended pension payments is 3.3 years. Also the median re-employment period of 100% suspended officials is about 20 month shorter than that of 1/2 suspended officials and it is shown in regression analysis that the possibility of re-retirement by 100% suspended officials is statistically significant higher than those of 50%. It specially expects greater influence if includes in case taking lump-sum or no making effect of re-employment because current system withhold pension payments even by earned income itself. Therefore, this analysis suggests suspension of pension payment properly applied according to the age and income together with "Delayed Retirement Credit" or "Partial Pension" for developmental alternatives of civil servant's suspension of pension payments. Furthermore, It is urgently needed that distinctive quality data about re-employment including earnings to perform deep-empirical research for effective policy. Lastly, it is extremely necessary to reinforce management system of Government Employment Pension Corporation.

• The Journal of the Korea Contents Association
• /
• v.20 no.2
• /
• pp.534-546
• /
• 2020

The purpose of this study is to prove the positive effect of mind and body healing through the modified meditation method of Southern Buddhism as a systematic practice to concentrate or empty consciousness of the Buddhist temple in Dhammakaya, Thailand. To investigate the effects of the program on the participants, the experimental measurement tools in this study include the Immeasurable scale, spirituality scale, simple mental test scale, and blood pressure scale, pulse meter, thermometer, and recorder. When the measured values were compared with the corresponding t-test, there were some differences before and after the measurements based on the significance probability p <0.05. As a result, there was a significant correlation between spiritual support scale and the Immeasurable scale. In addition, the results of analyzing the data through interviews showed that the body and physiologically effective concentration was well after the meditation experience, and the intention to actively utilize this meditation method was confirmed. In this study, it was confirmed that there was a positive effect of the Samata practice method of Concentration meditation(CM), and thus the theoretical and experimental effects of intensive meditation were presented. I hope that these studies will accumulate and follow-up studies will be conducted through intensive meditation as a healing effect.

• The KIPS Transactions:PartC
• /
• v.17C no.1
• /
• pp.119-128
• /
• 2010

In the shipbuilding industry, due to the global trends where the number of IT (Information Technology) devices of a smart ship have been increased rapidly, the need to develop a new shipboard backbone network has recently emerged for integrating and managing the IT devices of a smart ship efficiently. A shipboard backbone network requires high survivability because it is constructed in automatic and unmanned smart ships where a failure of the backbone network can cause critical problems. The purpose of this paper thus is to study SAN (Ship Area Network) as a efficient shipboard backbone network, considering particularity of shipboard environment and requirement of high survivability. In order to do so, we designed a dual network topology that all network nodes, including the IT devices installed in a smart ship, are connected each other through dual paths, and reuding tht IT devices pnstalles supporices network survivability as well as t Iffic efficiency for the dual network topology. And then, we verified the performance of the suggested SAN by theoretical and practical analysis including the graph theory, the probability theory, implemental specifications, and computer simulations.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.1
• /
• pp.1-7
• /
• 2004

Oriental Medicine has long been centered around Qi[vital force], hence adopting Qigong and the art of regimen for training the body and relaxing the mind so as to prevent and heal illness. It has not been such a long time since Qigong method had been performed and spot-lighted out of numerous methods in Oriental Medicine. In China and Korea alone, diverse cases and papers are published, only revealing so many steps toward the establishment of diachronic description, theoretical foundation, and clinical practice. Historical approach is an essential part of recognizing a subject. When you step along its path and comprehend what it were, you can also grasp what it is and what it will be. Establishment of Qigong history is also vital to research Qigong in theory and practice. Generally, Qigong was transmitted from China to Korea, whereas the opposite explanation, that it originated from Korean Taoism, is supported by the minority based on certain texts concerning ancient history. In this paper, I support the theory of Korean originality based on the following grounds: First, the location of Qi and Van, the motherland of Chinese Taoism provides a strong evidence that Korean tradition had been absorbed by them and formed the tradition of mystic hermits(shenxian). Second, Guangchengzi, the originator of mystic hermits, is from Dongyi tribe according to Cheonghakjib. Third, the myth of Dangun has pure form of unique Korean folklore possessing the distinctive feature of mystic hermits tradition, uninfluenced by Chinese Taoism. Fourth, in ideographical aspect, the character 'xian(仙)', was invented as the Korean concept of mystic hermits[xian] was flowed in to China. Moreover, There is high probability that it was based on the concept of mystic hermits shown in the myth of Dangun in Its original formation. Fifth, considering the relation between wild ginseng and the tradition of mystic hermits, that tradition can be formed very naturally in Korean area. Sixth, the analogical similarity between archetype of Korean tradition and Taoistic trilogy, the foundational idea of the tradition, gives genealogical basis to its origin. Seventh, the tradition of mystic hermits and Shamanism, which constitues the prototype of Korean mind as an original religious tradition, are undiscernible in their root In Conclusion, We can reach the idea that the origin of Qigong derives from Korean tradition, not that of China. The tradition of mystic hermits was transformed to ego-centric seclusionism when it faced the anarchy of Warring states period in China, whereas it was developed into humane proriety and worship of Heaven base on the programme of 'universal fraternity in pursuit of interst for man'. In prospect, it is highly required to develop and interpret traditional discipline methods in Korea so as to utilize them for clinical Qigong in practice.

• Korean Journal of Social Welfare
• /
• v.35
• /
• pp.51-83
• /
• 1998

This study is designed to find out the determinants of housewives' caregiving behavior to their elderly parents-in-law. For this purpose, a tentative path model, constructed with major socio-demographic variables in the caregiver's family as exogenous variables, is proposed to account for caregiver's behavior to elderly parents-in-law. The model is estimated with data collected from a probability sample of housewives in Kwangju, Korea. Estimation of the model, separately for caregiver's fathers-in-law and mothers-in-law, in terms of maximum likelihood(ML) procedures in LISREL8 reveals that housewives' educational attainment, father-in-law's age, father-in-law's health status, and family size have statistically significant causal. effects on care giving behavior to fathers-in-law, and that housewives' educational attainment, mother-in-law's age, family size, and caregiving attitude have significant causal effects on caregiving behavior to mothers-in-law. Comparison of the two estimated models indicates caregiver's educational attainment, caretaker's age, and family size are prominent determinants of caregiving behavior that can be commonly generalized to the two models. Except for these common determinants, however, a nonnegligible amount of differences is identified between the two models. The findings are discussed and interpreted with suggesting some salient theoretical and policy implications.