• 제목/요약/키워드: former researches

검색결과 149건 처리시간 0.031초

인터넷 검색추세를 활용한 빅데이터 기반의 주식투자전략에 대한 연구 (A Study on Big Data Based Investment Strategy Using Internet Search Trends)

  • 김민수;구평회
    • 한국경영과학회지
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    • 제38권4호
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    • pp.53-63
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    • 2013
  • Together with soaring interest on Big Data, now there are vigorous reports that unearth various social values lying underneath those data from a number of application areas. Among those reports many are using such data as Internet search histories from Google site, social relationships from Facebook, and transactional or locational traces collected from various ubiquitous devices. Many of those researches, however, are conducted based on the data sets that are accumulated over the North American and European areas, which means that direct interpretation and application of social values exhibited by those researches to the other areas like Korea can be a disturbing task. This research has started from a validation study against Korean environment of the former paper which says an investment strategy that exploits up and down of Google search volume on a carefully selected set of terms shows high market performance. A huge difference between North American and Korean environment can be eye witnessed via the distinction in profit rates that are exhibited by the corresponding set of search terms. Two sets of search terms actually presented low correlation in their profit rates over two financial markets. Even in an experiment which compares the profit rates with two different investment periods with the same set of search terms showed no such meaningful result that outperforms the market average. With all these results, we cautiously conclude that establishing an investment strategy that exploits Internet search volume over a specified word set needs more conscious approach.

경혈(經穴)의 의의(意義) 및 연구 방향에 관한 상수학적(象數學的) 고찰 (A Study on Consideration of the Concept and the Directions in Further Research of Meridian Points(經穴) Based on Symbolic Mathematical Study(象數學))

  • 계강윤;김병수
    • 대한한의학회지
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    • 제41권2호
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    • pp.9-22
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    • 2020
  • Objectives: The purpose of this study is to consider the concept of Meridian Points(經穴) and to establish the directions in further research. Methods: First, based on the latest results from the researches of Meridian and Collateral(經絡), it was to infer the original concept of Meridian Points(經穴). Second, the meaning of Meridian Points(經穴) has been investigated and its directions in further research was studied founded upon Symbolic Mathematical Study(象數學). Results & Conclusions : Firstly, Meridian Points(經穴) are considered to be the source of information that contains 365 numbers of human physiological information which includes physiological information of Viscera and Bowels(藏府) and Meridian and Collateral(經絡). Secondly, advanced researches are required further to clarify the meaning of Meridian Points(經穴) as Symbolic Mathematical Study(象數學) has established the systems of Meridian Points(經穴). In addition, the efficacy of each Meridian Points(經穴) needs to be revised through literature studies. Clinical studies are essential to practically verify the results from the former theoretical research. Thirdly, the contention to oppose the presence of Meridian and Collateral(經絡) and Meridian Points(經穴) was acknowledged to be incorrect. Lastly, for broadening the theoretical systems of Korean Medicine(韓醫學) with integration of Western scientific knowledge, a paradigm shift is necessary to revise the concepts of Viscera and Bowls(藏府), Meridian and Collateral (經絡) and Meridian Points(經穴) in Korean Medicine(韓醫學). In order to accomplish the shift, the ambiguity in theories of Korean Medicine(韓醫學) should be clarified through the study of Symbolic Mathematical Study(象數學).

키워드 네트워크 분석을 통한 지식구조 변화 연구 : 비즈니스 모델 연구를 중심으로 (A Study on the Change of Knowledge Structure through Keyword Network Analysis : Focus on Business Model Research)

  • 류재홍;최진호
    • 한국IT서비스학회지
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    • 제17권2호
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    • pp.143-163
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    • 2018
  • The business models has a great impact on the successful management of enterprises. Business environment has been shifting from industrial economy to knowledge-based economy. Enterprises go through numerous trials for successful management in the changing environment. Along with trial tests, research areas have been growing simultaneously. Although many researches have been conducted with regard to business models, it is very insufficient to systematically analyze the knowledge flow of research. Accordingly, successive researchers who want to study the business model may find it difficult to establish the orientation of future application research based on understanding the process of changing the knowledge structure that have accumulated so far. This study is intended to determine the current state of the business model research and to understand the process of knowledge structure changes in keywords that appear in 2,667 business model articles in the SCOPUS database. Identifying the knowledge structure has been completed through social network analysis, a methodology based on the 'relationship', and the changes in the knowledge structure were identified by classifying them into four different periods. The analysis showed that, first, the number of business model co-author increases over time with the need for academic diversity. Second, the 'innovation' keyword has the biggest center in the network, and over time, the lower-rank keyword which was in the former period has emerged as the top-rank keyword. Third, the cohesiveness group decreased from 12 before 2000 to 5 in 2015 and also the modularity decreased as well. Finally, examining characteristics of study area through a cognitive map showed that the relationships between domains increased gradually over time. The study has provided a systematic basis for understanding the current state of the business model research and the process of changing knowledge structure. In addition, considering that no research has ever systematically analyzed the knowledge structure accumulated by individual researches, it is considered as a significant study.

지식 맵을 위한 캐슁 기법 (A Caching Mechanism for Knowledge Maps)

  • 정준원;민경섭;김형주
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제10권3호
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    • pp.282-291
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    • 2004
  • 데이타를 효과적으로 다루기 위한 방법으로 데이타에 부가정보를 추가하는 TopicMap이나 RDF같은 지식맵에 대한 연구가 늘고 있다. 하지만 기존의 연구는 정보표현과 기술, 응용방안에 대한 연구가 주를 이루고 있으며 구현과 서비스에 대한 연구는 부족한 상태이다. 본 논문에서는 TopicMap 시스템에서의 캐쉬 관리 기능의 구현을 통해 실질적인 지식맵 서비스를 지원하기 위해 고려해야 할 부분 중에서 지식맵의 효과적인 접근을 지원하기 위한 방법을 제안하였다. 먼저 기존 탐색방법의 장점을 최대한 수용하는 탐색 기법을 제안하고 이러한 환경하에서 지식맵 전송 효율을 향상시키고자 지식맵이 가지는 정보를 이용하는 캐쉬기법을 제안하였다. 본 논문에서 제안한 캐쉬기법은 어플리케이션의 접근 형태에 따른 물리, 논리적 단위로 정보를 캐쉬하는 기존의 방식과 달리 사용자가 지식을 접근하는 관점에서 효율을 높이고자 하였다. 즉 지식맵이 이미 자신에 대한 부가 정보뿐만 아니라 다른 지식간의 연관관계와 같은 정보를 가지고 있으므로 이러한 정보를 클러스터링 요소로 이용, 실제 사용 자가 지식맵을 탐색하는데 있어 접근확률이 높도록 캐쉬집합을 생성하도록 하였다. 또한 캐쉬집합을 교체 하는 방법에 있어서도 지식맵의 그래프 관계와 같은 정보의 연관성을 이용, 필요한 부분만을 전송함으로써 효율을 높이는 방법을 제안하였다.

전환장벽의 귀인이 부정적 감정과 불평행동에 미치는 영향 (The Effect of Attributions to Switching Barrier on Negative Emotions and Complain Behaviors)

  • 정윤희
    • 경영과정보연구
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    • 제36권2호
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    • pp.223-237
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    • 2017
  • 전환장벽은 고객의 이탈을 막는다는 점에서 주로 긍정적인 측면이 강조되었으나, 최근에는 기업이 설정한 전환장벽이 장기적으로 해로울 수 있음이 논의되기 시작하였다(Jones et al. 2000; 정윤희, 2012). 전환장벽의 부정적 영향에 관한 기존연구에서는 전환장벽이 소비자의 전환의 자유를 방해한다는 점에서 부정적 심리반응을 이끌 수 있음은 보여주었으나, 당장 기업에 줄 수 있는 부정적인 영향에 대한 논의는 부족하였다. 따라서 본 연구에서는 전환장벽으로 인해 전환을 못하는 상황에 서비스 실패상황에 관한 연구를 적용하여 소비자들의 전환장벽에 대한 부정적 감정과 불평행동에 대한 연구를 진행하고자 하였다. 전환을 어렵게 하는 전환장벽의 귀인(내적 혹은 외적)에 따라 후회와 원망을 경험하게 되고 이는 수용, 불평행동, 부정적 구전으로 이어질 것으로 가정하였다. 구조방정식 모형을 이용해 가설 검증한 결과, 내적귀인은 후회에 긍정적 영향을 주고, 외적귀인은 원망에 긍정적 영향을 주는 것으로 나타났다. 그리고 후회는 수용과 불평행동에 영향을 주고, 원망은 불평행동과 부정적 구전에 긍정적 영향을 미침을 확인하였다. 이러한 결과는 전환장벽이 고객들의 부정적 감정과 불평행동을 이끌어 기업에 즉각적 피해를 줄 수 있음을 보여줌으로써 기존연구를 확장하고 있으며, 전환장벽에 대한 신중한 실무적 활용을 시사한다.

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Marine Terraces of the Eastern Coast of Korean Peninsula

  • Park, Seong-Gil
    • 한국제4기학회지
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    • 제17권2호
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    • pp.15-15
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    • 2003
  • In South Korea, marine terraces have been well developed along the eastern coastal zone, and previous researches on the marine terraces have also been focused on to this coastal zone. The marine terraces of the eastern coast of South Korea had been classified into three terrace groups, that is, the higher, middle, and lower surface ones, according to the heights of marine terraces by previous studies(Oh, 1981 ;Chang, 1987 ;Yoon et. al, 1999, 2003 ; Hwang and Yoon, 1996 etc.). Recently, however, it tends to classify the marine terraces based on the concept of geomorphic surface units(Lee, 1987 ; Kim, 1990 ; Choi, S. 2003; Choi S. et. al 2003a,b, etc). For example, it was proposed that the marine terrace surfaces of Eupcheon coast of the southeastern coastal area of Korea could be classified into 16 geomorphic surfaces, i.e., Eupcheon 1terrace(former shoreline height of 160m), 2(153m), 3(140m), 4(130m), 5(124m), 6(115m), 7(100m), 8(92m), 9(82m), 10(71m), 11(62m), 12(53m), 13(43m), 14(35m), 15(18m) and 16(10m) surfaces, in descending order, according to the former shoreline heights(Choi, S, 2003 ; Choi, S. et. al, 2003a,b). Among these terraces, Eupcheon 1, 2, 4, 5 and 7 surfaces had not been reported in previous works. Among the above mentioned marine terraces, Eupcheon 15 terrace, the most widely and continuously distributed marine terrace have been identified as marine terrace of the Last Interglacial culmination period(oxygen isotope stage 5e) which was based on amino acid dates(124∼125ka BP) and geomorphological features such as red soil, pollen analysis, fossil cryogenic structures and crossing terrace concept. Eupoheon 15 terrace surfaces have also been proposed as the key surface for the identification and correlation of the so-called '5e' marine terrace in the eastern coast of South Korea. This terrace was reconfirmed as the Last Interglacial culmination period, which was based on the identification of Ata tephra, one of the wide-spread marker tephra which indicates the Last Interglacial culmination period in Japan by Sasaki et. al(2002). It was thought that marine terraces of the eastern coast of South Korea had been formed by the steady-state uplifting during the Quaternary glacio-eustatic sea level changes(Choi, 1997). The uprift rate of 10cm/1,000years had been proposed in the eastern coast of South Korea based on the former shoreline altitude(18m) of the above Eupcheon 15 terrace. Therefore, it can be estimated that Eupcheon 1 terrace had been formed in the early Pleistocene from the above uprift rate. The OSL dating for the samples of Eupcheon 7, 9, 13, 15 and 16 terraces and identification of marker tephra in the terrace deposits are in progress. It is expected that more elaborate chronology on themarine terraces of the eastern coast of South Korea could be established by these absolute dates and marker-tephra.

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유압 호스에서의 주파수 계열 음속 계측법 개발 (A Method for Measuring the Frequency Series Wave Speed in Hydraulic Hose)

  • 강만곤;이일영
    • 유공압시스템학회논문집
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    • 제3권2호
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    • pp.21-26
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    • 2006
  • With the increasing concerns on noise and vibration in hydraulic fluid power systems, it is important to find better way to reduce noise and vibration. In this study, the authors survey former researches on hose(viscoelastic tube) modeling in advance. And a summary of several existing methods for measuring the speed of sound in the fluid in pipes is presented. Their basic principles, advantages and limitations are compared. And The authors suggest a far simple identification procedure to obtain wave speed in hose by just using an experimental pressure data for the object tube with hose. In the new procedure, flow in hose is basically modeled by transfer matrix method, and wave speed in hose is obtained as data in frequency series. The wave speed in hose as data in frequency series will be used to compute the pressure pulsation attenuation in hydraulic pipe systems. The computed results are compared with the experimental ones, and the validity of the new procedure to obtain wave speed in hose is confirmed

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A Research on the Establishment of New Korea-Russia Bilateral Cooperation Law for the Sustainable Arctic Development

  • Kim, Bongchul
    • Journal of Contemporary Eastern Asia
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    • 제19권1호
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    • pp.84-96
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    • 2020
  • The Republic of Korea (Korea) and the Russian Federation (Russia) are actualizing the cooperation in the Arctic area. As a result, Korean companies have begun to enjoy real economic benefits. However, since there are some troublesome aspects associated with this cooperation, measures that can lead to sustainable development through the supplementation of relevant norms are critical. Russia is also aware of these problems in obtaining economic benefits in the future; cooperation between the two countries should be extended to sufficiently cover this point. The laws related to the region are vague and do not encompass every field. In addition, when it comes to national interests, many situations arise from areas where international and national laws are not clearly harmonized. Therefore, efforts should be made to reflect the interests of both sides and to maintain economic benefits, in case Korea participates in Russia's development of the area, as well as for the legal foundation to reduce negative issues. The Korea-Russia Free Trade Agreement (FTA) negotiation is on the track for the purpose. The two governments should consider various tasks, such as harmonizing with the former FTAs and dealing with the domestic law in accordance with the new FTA. The two countries also have to conduct researches on the efficient use of the FTA and for the 'Sustainable Arctic Development'.

A Development of Forward Inference Engine and Expert Systems based on Relational Database and SQL

  • Kim, Jin-Sung
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 추계 학술대회 학술발표 논문집
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    • pp.49-52
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    • 2003
  • In this research, we propose a mechanism to develop an inference engine and expert systems based on relational database and SQL (structured query language). Generally, former researchers had tried to develop an expert systems based on text-oriented knowledge base and backward/forward (chaining) inference engine. In these researches, however, the speed of inference was remained as a tackling point in the development of agile expert systems. Especially, the forward inference needs more times than backward inference. In addition, the size of knowledge base, complicate knowledge expression method, expansibility of knowledge base, and hierarchies among rules are the critical limitations to develop an expert systems. To overcome the limitations in speed of inference and expansibility of knowledge base, we proposed a relational database-oriented knowledge base and forward inference engine. Therefore, our proposed mechanism could manipulate the huge size of knowledge base efficiently, and inference with the large scaled knowledge base in a short time. To this purpose, we designed and developed an SQL-based forward inference engine using relational database. In the implementation process, we also developed a prototype expert system and presented a real-world validation data set collected from medical diagnosis field.

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Probabilistic Safety Assessment for High Level Nuclear Waste Repository System

  • Kim, Taw-Woon;Woo, Kab-Koo;Lee, Kun-Jai
    • Journal of Radiation Protection and Research
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    • 제16권1호
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    • pp.53-72
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    • 1991
  • An integrated model is developed in this paper for the performance assessment of high level radioactive waste repository. This integrated model consists of two simple mathematical models. One is a multiple-barrier failure model of the repository system based on constant failure rates which provides source terms to biosphere. The other is a biosphere model which has multiple pathways for radionuclides to reach to human. For the parametric uncertainty and sensitivity analysis for the risk assessment of high level radioactive waste repository, Latin hypercube sampling and rank correlation techniques are applied to this model. The former is cost-effective for large computer programs because it gives smaller error in estimating output distribution even with smaller number of runs compared to crude Monte Carlo technique. The latter is good for generating dependence structure among samples of input parameters. It is also used to find out the most sensitive, or important, parameter groups among given input parameters. The methodology of the mathematical modelling with statistical analysis will provide useful insights to the decision-making of radioactive waste repository selection and future researches related to uncertain and sensitive input parameters.

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