• Title/Summary/Keyword: two-level tries

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Hydraulic Characteristic Analysis for Prevention of River Disaster at Estuary in the Eastern Coast of Korea (동해안 하천 하구부의 하천재해 방지를 위한 수리특성 분석)

  • Choi, Jong-Ho;Jun, Kye-Won;Yoon, Yong-Ho
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.2
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    • pp.83-89
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    • 2018
  • The significant sedimentation at the estuary in the eastern coast of Korea frequently causes river mouth occlusion where disconnection between the river and sea is observed. River mouth occlusion causing watershed retention raises the environmental risk of the area as it impairs water quality and threatens the area's safety in the event of floods. This study proposes a plan to maintain stability of river channel and flow of flood discharge at the estuary with loss of its function for disaster prevention. To this end, the study tries to change the location and width of stream path, focusing on the center line of stream near the sand bar of river mouth. This allows to identify a shape of stream path that leads the most stable flow. To review the result, this study uses the SRH-2D, a model for two-dimensional hydraulic analysis, and conduct numeric simulation. The simulation result showed that the most effective plan for maintaining the stable flow of running water without having the area sensitive to changes in hydraulic characteristics is to lower the overall river bed height of the sand bar near the center line of stream to a equal level.

Study on the Economic Co-operation action by analyzing the North Korea's Military Negotiations - Focusing on Inter-Korean Military Talks and working level talks about Gaeseong industrial complex - (북한 협상모델 분석을 통한 경제협력 실천방안 연구 - 남북 군사협상 및 개성공단 실무회담 사례를 중심으로-)

  • Lee, Sung-Choon
    • International Commerce and Information Review
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    • v.15 no.3
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    • pp.353-384
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    • 2013
  • When it comes to the current inter-Korean relationship, the two Koreas are in the step of core practical negotiation on exchanges and cooperation away from deadlock so far. It is expected that they will have more and frequent meetings in the future. Therefore, now is the time the South Korea needed to come up with systematic countermeasures because there is nothing more important and giving more impact on our society than the matter of North Korea. As the purpose of social science lies with the explanation and prediction of the social phenomena in the society, it is considered to be meaningful to analyze the representative military negotiations such as the defense ministry-level talks, general-level talks, and working-level talks between the two Koreas where the participants from South Korea consisting of the military representatives discussed with their counterparts of North Korea since the signing of the armistice in Korea on July 27, 1953. This study analyzes and evaluates the behaviors of North Korea's military negotiations with the South Korea in the Kim Jong-il era on the overall basis. In particular, the research tries to prove that the behaviors of military negotiations under Kim Jeong-il regime were made in the frame of the negotiation model by analyzing many negotiations presented in 'With Century', Kim Il Sung's Memoirs under his anti-Japan-guerilla era and suggesting the analysis frame of anti-Japan-guerilla style negotiation model. Based on the results of this proof, the study looks at carefully the specific characteristics of anti-Japan guerrilla-type negotiation.

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A Study on Airlines' Choice Behavior of Aircraft Size (항공사의 항공기 용량 선정 행위에 관한 연구)

  • Kim, Bong-Gyun;Yoo, Kwang-Eui
    • Journal of Advanced Navigation Technology
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    • v.4 no.2
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    • pp.114-131
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    • 2000
  • An airline should consider the number of seats or size of aircraft, when it composes fleet or selects a type of aircraft for some routes. There are two major factors considered for this choice problem under the assumption that the objectives of an airline is a profit maximization: the operating cost and revenue from the aircraft operated. This research tries to solve the problem of aircraft size selection by airline. The study applies four steps to get optimal choice of aircraft size: (1) cost analysis for the relationship between airline operation cost and aircraft size: (2) market share and revenue analysis: (3) flight segment-level analysis, based on the derived cost, demand and revenue functions: and (4) network-level analysis to see how airlines make choice of aircraft size systematically at a network level. An airline can accommodate the increasing air travel demand by either increasing operation frequency, or increasing aircraft size that is represented by seat capacity, or both. Airport runway capacity and productivity depend on the size of aircraft used at airport. This paper presents the understanding of how airlines make decisions on the size of aircraft to operate, how they will adjust their choices when airport capacity is constrained, and how public regulation such as policy for landing fees could influence airlines' aircraft choice.

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The Tactical review of the Battle of Tsushima - with focus on disposition & maneuver, and damage control - (쓰시마 해전의 전술적 재조명 - 배진과 기동, 손상통제를 중심으로 -)

  • Lee, Chang Hyun
    • Strategy21
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    • s.44
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    • pp.213-253
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    • 2018
  • The Russo-Japanese War(1904-1905) in the early 20th century greatly influenced the international politics in Northeast Asia and the destiny of both countries. There are many studies on the cause of the outbreak and its effect on the Korean peninsula. The victory and defeat of the battle of Tsushima also the subject of research by renowned scholars and navy officers. Many previous studies have analyzed the process of engagement. However, There was a lack of research that analyzed at the tactical level of naval commanders. Therefore, this study tries to review the battle of Tsushima in terms of tactical level, that is formation, maneuvering, damage control. Naval operations at sea with many variables are not always done as planned. The intuitive judgement and readiness have had a decisive impact on victory and defeat. The analysis of the naval warfare on the basis of formation, maneuvering, and damage control makes the cause of the win more clearly. The conclusion of the this study can be summarized in five ways. First, victory would be achieved through the suppression of the beginning. The destiny of the Tsushima battle was determined by an 1 hour after first firing. The Japanese fleet caught fire by paralyzing the command and control capabilities of the Russian fleet. Second, the Japanese fleet's power was superior to the Russian fleet. In general, Japan and Russia had similar powers, and Admiral Togo's "T crossing tactics" decisively contributed the victory. However, when compared to the weapon system level, formation and maneuvering, Japan was much more dominant. Third, people realized that one side to be annihilated in the battle between similar powers after the Tsushima battle. The common perception before the Battle of Tsushima was that the battle ship would not sunken, and that the result of wiping out was difficult. However, there is s time for one sided victory and defeat depending on the early suppression nad the destruction of the command and control ability. Fourth, it is the importance of damage control ability. The main cause of the Russian fleet's loss of command and control ability was thick smoke from fire, and maneuverability was greatly deteriorated due to coal overload. In this way, importance is still valid after more than 100 tears. Fifth, the area of uncertainty. In the navy battles, one or two shots of clear firing in the beginning and small misconception and minor mistakes decide win or loss. Ultimately, this area of fortune can be linked to mindset of the commander. I hope this research will be help to naval researchers and naval commanders at the sea.

Impact of National Culture on Service Quality Evaluations : Comparison of Korea and Anglo-Saxon Countries (국가문화가 서비스품질의 평가에 미치는 영향 : 한국과 영·미권 국가의 비교)

  • Nam, Sung-Jip
    • Journal of Distribution Science
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    • v.13 no.11
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    • pp.93-100
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    • 2015
  • Purpose - The objective of this research is to investigate whether national culture influences consumers' service evaluations. The services industry is receiving increasing attention from academia and practitioners as its position grows in global markets. Standardization or localization is a traditional managerial decision in global business. As the boundaries of services expand across national borders, firms are required to decide whether to standardize services or adjust to local needs. Though it is imperative to reflect global perspectives in marketing theories, these perspectives are mostly based on Western conceptualization of the world. Through a comparison of consumer groups from two culturally remote countries, service quality evaluation mechanisms are examined based on similar stimuli. The study tries to expand service marketing perspectives across national borders. Research design, data, and methodology - Eastern and Western countries are known to be culturally distinct. One Eastern and one Western country were chosen: an Anglo-Saxon country (the U.S., England, and Australia) and South Korea. In Hofstede's cultural dimensions, the differences between the two are pronounced. The Anglo-Saxon based countries share many similarities. Samples of the same sites are targeted. Questionnaires using a service quality scale (SERVQUAL) and a customer satisfaction scale were distributed. Utilizing Hofstede's typology of culture, the service evaluation mechanisms of the respondents from the two groups are evaluated. Three hypotheses are proposed from the review of the literature. These are service evaluation habits, importance of service quality dimensions for the individualistic/collectivistic countries, and strong/weak uncertainty avoidance cultures. Consumers from the individualistic countries are considered to care about themselves and demand a higher level of responsiveness and assurance. On the other hand, consumers from high uncertainty avoidance cultures are assumed to rely more on tangible questions of service quality, as these are the only predictable service quality indicators. A t-test and regression analysis are applied to validate the constructs. Results - The respondents from the Anglo-Saxon countries are more generous on service evaluations than Koreans. Researchers have indicated that Americans tend to give higher service evolution scores than European, Mexican, and Korean counterparts. The tendency is the same here. The sample from Anglo-Saxon countries demonstrated higher service evaluation scores on every dimension of SERVQUAL. For the second hypothesis, the respondents from the collectivistic culture rely less on core service dimensions (assurance and responsiveness) due to their tendency to place more value on group harmony than individual interest. However, the third hypothesis was not validated. Conclusions - The study attempted to expand the scope of service marketing to reflect cross-national perspectives. Service quality is known to have a strong influence on customer satisfaction and loyalty behavior. However, this research demonstrated that individuals from different cultural territories respond heterogeneously to the same stimuli. Scholars argue that national cultures are main factors in such deviated behavior. Scholars and global managers should be aware of differences in consumer value judgment mechanisms such as satisfaction, expectations, and perceptions.

Exchange Rate Changes Cause Conflicting Effects on Improving the Quality and Increasing Market Share of Eco-friendly Vehicles (환율 변화의 친환경 자동차 품질 향상과 시장점유율 확대에 대한 상충효과)

  • Seo, Cheong-Seog
    • Environmental and Resource Economics Review
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    • v.29 no.3
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    • pp.313-333
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    • 2020
  • This paper shows that when the exchange rate changes, there are conflicting effects on improving the quality and increasing market share of eco-friendly vehicles. In a vertically differentiated duopoly model consisting of high quality clean cars and low quality internal combustion engine cars, I set up a two-stage noncooperative game under perfect information that the quality levels and the prices of the cars are competitively determined. The vehicles are assumed to be produced in countries that use distinct currencies. When the exchange rate of the country that produces low quality cars rises, the producer prefers to intensify competition due to the relatively lowed cost, and the incentive for quality improvement arises from the intension of attempting to reduce the degree of differentiation of quality level. At this time, the clean car manufacturing firm tries to avoid competition due to weakened competitiveness, and increases the quality level to expand quality differentiation. However, in this case, the market share of eco-friendly vehicles shrinks. On the other hand, if the exchange rate changes in the opposite direction, the market share of eco-friendly vehicles is expected to increase, but the quality of both cars are deteriorated, causing a conflict effect.

A Conjoint Analysis of Online Information Privacy Concerns: A case in Korea (온라인 프라이버시 침해 우려에 관한 컨조인트 분석 : 한국에서의 사례)

  • Choi, Mi-Young;Lee, Sang-Yong Tom
    • Asia pacific journal of information systems
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    • v.18 no.3
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    • pp.45-65
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    • 2008
  • The rapid growth of the Internet has increased the amount of transmission of personally identifiable information. At the same time, with new Internet related technologies, organizations are trying to collect and access more personal information than before, which in turn makes individuals concern more about their information privacy. For their successful businesses, organizations have tried to alleviate these concerns in two ways: (1) by offering privacy policies that promise certain level of privacy protection; (2) by offering benefits such as financial gains or convenience. In this paper, we interpret these actions in the context of the information processing theory of motivation. This paper follows Hann et al.(2007)'s methods to analyze Internet users privacy concerns in Korea and tries to compare the findings. Our research objectives are as follows: First, we analyze privacy concern mitigation strategies in the framework of the expectancy theory of motivation. Subsequently, we show how the expectancy theory based framework is linked o the conjoint analysis. We empirically validate the predictions that the means to mitigate privacy concerns are associated with positive valences resulting in an increase in motivational score. In order to accommodate real-life contexts, we investigate these means in trade-off situation, where an organization may only be able to offer partially complete privacy protection and/or promotions and/or convenience, While privacy protection (secondary use, improper access) are associated with positive valences, we also find that financial gains can significantly increase the individuals' motivational score of a website in Korea. One important implication of this empirical analysis is that organizations may possess means to actively manage the privacy concerns of Internet users. Our findings show that privacy policies are valued by users in Korea just as in the US or Singapore. Hence, organizations can capitalize on this, by stating their privacy policy more prominently. Also organizations would better think of strategies or means that may increase online users' willingness to provide personal information. Since financial incentives also significantly increase the individuals' motivational score of website participation, we can quantify the value of website privacy protection in terms of monetary gains. We find that Korean Internet users value the total privacy protection (protection against errors, improper access, and secondary use of personal information) as worthy as KW 25,550, which is about US 28. Having done this conjoint analysis, we next adopt cluster analysis methodology. We identify two distinct segments of Korea's internet users-privacy guardians and information sellers, and convenience seekers. The immediate implication of our study is that firms with online presence must differentiate their services to serve these distinct segments to best meet the needs of segments with differing trade-offs between money and privacy concerns. Information sellers are distinguished from privacy guardians by prior experience of information provision, To the extent that businesses cannot observe an individual's prior experience, they must use indirect methods to induce segmentation by self-selection as suggested in classic economics literature of price discrimination, Businesses could use monetary rewards to attract information sellers to provide personal information. One step forward from the societal trends that emphasize the need of legal protection of information privacy, our study wants to encourage organizations and related authorities to have the viewpoints to consider both importance of privacy protection and the necessity of information trade for the growth of e-commerce.

A Study on Empirical Model for the Prevention and Protection of Technology Leakage through SME Profiling Analysis (중소기업 프로파일링 분석을 통한 기술유출 방지 및 보호 모형 연구)

  • Yoo, In-Jin;Park, Do-Hyung
    • The Journal of Information Systems
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    • v.27 no.1
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    • pp.171-191
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    • 2018
  • Purpose Corporate technology leakage is not only monetary loss, but also has a negative impact on the corporate image and further deteriorates sustainable growth. In particular, since SMEs are highly dependent on core technologies compared to large corporations, loss of technology leakage threatens corporate survival. Therefore, it is important for SMEs to "prevent and protect technology leakage". With the recent development of data analysis technology and the opening of public data, it has become possible to discover and proactively detect companies with a high probability of technology leakage based on actual company data. In this study, we try to construct profiles of enterprises with and without technology leakage experience through profiling analysis using data mining techniques. Furthermore, based on this, we propose a classification model that distinguishes companies that are likely to leak technology. Design/methodology/approach This study tries to develop the empirical model for prevention and protection of technology leakage through profiling method which analyzes each SME from the viewpoint of individual. Based on the previous research, we tried to classify many characteristics of SMEs into six categories and to identify the factors influencing the technology leakage of SMEs from the enterprise point of view. Specifically, we divided the 29 SME characteristics into the following six categories: 'firm characteristics', 'organizational characteristics', 'technical characteristics', 'relational characteristics', 'financial characteristics', and 'enterprise core competencies'. Each characteristic was extracted from the questionnaire data of 'Survey of Small and Medium Enterprises Technology' carried out annually by the Government of the Republic of Korea. Since the number of SMEs with experience of technology leakage in questionnaire data was significantly smaller than the other, we made a 1: 1 correspondence with each sample through mixed sampling. We conducted profiling of companies with and without technology leakage experience using decision-tree technique for research data, and derived meaningful variables that can distinguish the two. Then, empirical model for prevention and protection of technology leakage was developed through discriminant analysis and logistic regression analysis. Findings Profiling analysis shows that technology novelty, enterprise technology group, number of intellectual property registrations, product life cycle, technology development infrastructure level(absence of dedicated organization), enterprise core competency(design) and enterprise core competency(process design) help us find SME's technology leakage. We developed the two empirical model for prevention and protection of technology leakage in SMEs using discriminant analysis and logistic regression analysis, and each hit ratio is 65%(discriminant analysis) and 67%(logistic regression analysis).

The Impacts of Education and Non-Labor Income on Employment Among the Elderly: An Estimation with a Panel Logit Model to Address the Problem of Endogenous Predictors (교육수준과 비근로소득이 고령자 취업에 미치는 영향: 내생성을 고려한 패널로짓 모형 추정)

  • Kim, Cheoljoo
    • 한국사회정책
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    • v.23 no.1
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    • pp.95-123
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    • 2016
  • As Korean society grows rapidly older, a systematic analysis of the determinants of labor supply behavior among the elderly becomes a prerequisite for designing more effective senior employment policies and income security regime for the elderly. Literatures review shows that a majority of previous researches have been ignoring the problem of "endogenous predictor" especially when it comes to the estimation of the effects of the two key variables, education and non-labor income, on labor supply decisions among older people. They have failed to take into consideration the unobserved heterogeneities which might affect both labor supply decisions of the elderly and their levels of education and non-labor income, which means, according to some econometric literatures, that the estimated coefficients of the two predictors can be inconsistent. The paper tries to redress the endogeneity problem by employing a panel logit model with data from the 1st. to 4th. wave of the KLoSA(Korean Longitudinal Survey of Ageing) to estimate the effects of key predictors on the probability of getting jobs among older people(ages of 60 or older). Both a random effects and a fixed effects model reaffirms that non-labor income has a negative effect on the chances of being employed. And a random effects model shows that the effect of education is also negative, as has frequently been reported by previous studies. That means the effects of education and non-labor income on elderly employment remain negative after the effect of unobserved heterogeneities is controled for and the problem of endogenous predictors is redressed through an appropriate panel data analysis. These findings mean, in turn, that when Korean baby-boomers, who had acquired an unprecedentedly higher level of education and were expected to enjoy ever-larger amount of non-labor income than their preceding generations, retires in near future, their incentives to work will become much weaker and the lack of labor-force and the burden of financing increased public pension expenditure will become more troublesome. The paper concludes with recommending some policy initiatives helpful to solve these expected problems.

Dynamic Price-Based Call, Admission Control Algorithm for Multi-Class Communication Networks (다중클래스 통신망을 위한 동적 과금 기반의 호수락 제어 알고리즘)

  • Gong, Seong-Lyong;Lee, Jang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.8B
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    • pp.681-688
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    • 2008
  • In this paper, we propose a new price-based call admission control algorithm for multi-class communication networks. When a call arrives at the network, it informs the network of the number of requested circuits and the minimum amount of time that it will require. The network provides the optimal price for the arrived call with which it tries to maximize its expected revenue. The optimal price is dynamically adjusted based on the information of the arrived call, and the present and the estimated future congestion level of the network during the reservation time of the call. If the call accepts the price, it is admitted. Otherwise, it is rejected. We compare the performance of our dynamic pricing algorithm with that of the static pricing algorithm by Courcoubetis and Reiman [1], and Paschalidis and Tsitsiklis [2]. By the comparison, we show that our dynamic pricing algorithm has better performance aspects such as higher call admission ratio and lower price than the static pricing algorithm, although these two algorithms result in almost the same revenue as shown in [2]. This implies that, in the competitive situation, the dynamic pricing algorithm can attract more users than the static pricing algorithm, generating more revenue. Moreover, we show that if a certain fixed connection fee is introduced to the price for a call, our dynamic pricing algorithm yields more revenue.