• Title/Summary/Keyword: 작업사건

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Data-Driven Exploration for Transient Association Rules (한시적 연관규칙을 위한 데이타 주도 탐사 기법)

  • Cho, Ll-Rae;Kim, Jong-Deok;Lee, Do-Heon
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.4
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    • pp.895-907
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    • 1997
  • The mining of assciation rules disovers the trndency of events ocuring simultaneously in large databases. Previous announced research on association rules deals with associations with associations with respect to the whole transaction. However, xome association rules could have very high confidence in a sub-range of the time domain, even though they do not have quite high confidence in the whole time domain. Such kind of association rules are ecpected to be very usdful in various decion making problems.In this paper, we define transient association rule, as an association with high cimfidence worthy of special attention in a partial time interval, and propose an dfficeint algorithm wich finds out the time intervals appropriate to transient association rules from large-databases.We propose the data-driven retrival method excluding unecessary interval search, and design an effective data structure manageable in main memory obtined by one scanning of database, which offers the necessary information to next retrieval phase. In addition, our simulation shows that the suggested algorithm has reliable performance at the time cost acceptable in application areas.

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Trend-based Sequential Pattern Discovery from Time-Series Data (시계열 데이터로부터의 경향성 기반 순차패턴 탐색)

  • 오용생;이동하;남도원;이전영
    • Journal of Intelligence and Information Systems
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    • v.7 no.1
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    • pp.27-45
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    • 2001
  • Sequential discovery from time series data has mainly concerned about events or item sets. Recently, the research has stated to applied to the numerical data. An example is sensor information generated by checking a machine state. The numerical data hardly have the same valuers while making patterns. So, it is important to extract suitable number of pattern features, which can be transformed to events or item sets and be applied to sequential pattern mining tasks. The popular methods to extract the patterns are sliding window and clustering. The results of these methods are sensitive to window sine or clustering parameters; that makes users to apply data mining task repeatedly and to interpret the results. This paper suggests the method to retrieve pattern features making numerical data into vector of an angle and a magnitude. The retrieved pattern features using this method make the result easy to understand and sequential patterns finding fast. We define an inclusion relation among pattern features using angles and magnitudes of vectors. Using this relation, we can fad sequential patterns faster than other methods, which use all data by reducing the data size.

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Developing Automatic Lens Module Assembly System Using 3D Simulation (3D 시뮬레이션을 활용한 렌즈모듈 자동화조립시스템 개발)

  • Moon, Dug-Hee;Lee, Jun-Seok;Baek, Seung-Geun;Zhang, Bing-Lin;Kim, Yeong-Gyoo
    • Journal of the Korea Society for Simulation
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    • v.16 no.2
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    • pp.65-74
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    • 2007
  • Virtual manufacturing (VM) is a powerful technology for developing a new product, new equipment and new manufacturing system, and three-dimensional (3D) simulation is a core technology in VM. 3D simulation involves both mechanical simulation and discrete event simulation. This paper introduces a case study of implementing 3D simulation for developing an automatic assembly line in a Korean optical factory. This factory produces a lens module that is the part of a phone-camera. 3D simulation technology is applied from the early stage of development. In the conceptual design and the initial design phases for individual equipment, 3D mechanical simulation using $CATIA^{(R)}$ and $IGRIP^{(R)}$ is conducted. 3D discrete event simulation with $QUEST^{(R)}$ is applied to the detailed design of the equipment and of the whole system. The focus of the simulation is to verify the technical and economical feasibility of the new automatic system. As a result, the takt time is reduced to the quarter of the manual system, and the number of workers in a line is reduced tremendously.

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Supporting Geo-Workflow Management through Object Activity Model (객체행위모델을 통한 지형정보 프로세스 관리)

  • Liou, Jaeik;Ryu, Keun Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.4 no.2
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    • pp.1-16
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    • 2001
  • Management of geo-workflow's changes is one of growing issues and requires more advanced ways and methods to deal with heterogeneous modifications and interactions of process, activity and event over time. A few dominant workflow models have coped with these subjects. There is, however, little consensus for explanation of six dimensions with regard to actor, activity, space, time, reason and effect. This study begins with examining environments of six dimensions and the Hexad model is proposed to elucidate the causes and results of a wide variety of geo-processes and activities. In this paper, we will introduce Hexad Object Activity Model making it possible to interpret manifest motivations, conditions and actions. Full descriptions of six dimensions are often useful for applying to the handling of diverse activities particularly requiring to clarify actor's goal and role at a specific time and space.

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DEVS Modeling with Hierarchical Planning: HRG-DEVS (계층적 계획을 이용한 이산 사건 시뮬레이션 모델링: HRG-DEVS)

  • Yi, Mi-Ra
    • Journal of the Korea Society for Simulation
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    • v.15 no.2
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    • pp.1-12
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    • 2006
  • As the needs of intelligent systems increase, there have been diverse approaches that combine artificial intelligence (AI) and simulation in the last decade. RG-DEVS, which is the basis for this paper, embedded AI planning techniques into the simulation modeling methodology of DEVS, in order to specify dynamically a simulation model. However, a hierarchy concept, which is used for various types of problem solving systems. is not included in the planning of RG-DEVS. The hierarchy concept reduces the computational cost of planning by reducing the search space, and also makes it easy to apply the hierarchical process flow of a target system to planning. This paper proposes Hierarchical RG-DEVS (HRG-DEVS) in an attempt to insert hierarchical planning capability into RG-DEVS. For the verification of the proposed modeling methodology, HRG-DEVS is applied to model the block's world problem of ABSTRIPS, which is a classical planning problem.

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A Simulation Study for Evaluation of Alternative Plans and Making the Upper-limit for Improvement in Productivity of Flow-shop with Considering a Work-wait Time (흐름생산 공정에서의 작업 대기시간을 고려한 공정 개선 상한선 도출 : H사의 공정 개선 계획안 시뮬레이션 사례를 중심으로)

  • Song, Young-Joo;Woo, Jong-Hun;Lee, Don-Kun;Shin, Jong-Gye
    • Journal of the Korea Society for Simulation
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    • v.17 no.2
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    • pp.63-74
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    • 2008
  • The design of best efficient production process is common requirements of the production strategy department and the process planning department to maximize the revenue and accomplish target production volumes in the production periods. And they use several general methods for that-line-balancing, removing of the bottle-neck process, facility ramp-up, increasing of the worker's utilization, etc. But, those methods have depended on analytic, static and arithmetic calculations, yet. So, irregular work-waiting time causing the delay time isn't include in extracting production capacity, especially in the line production process. The work-waiting time is changed irregularly along the variation of each machine and very important for calculate real product lead-time and forecasting target production volumes. At this thesis, i'm going to mention the importance of the delay time of conveyor system which can be extracted by discrete-event simulation. And suggest it as a new main variable that must be considered at designing new production system. Then experimented and tested that's effects in the H-company case, conveyor based line production process.

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Analysis of the Sea Condition on the Patrol Ship Cheonan Sinking Waters (천안호 침몰해역의 해상조건 분석)

  • Kim, Kang-Min;Lee, Joong-Woo;Kim, Kyu-Kwang;Kwon, So-Hyung;Lee, Hyung-Ha
    • Journal of Navigation and Port Research
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    • v.34 no.5
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    • pp.349-354
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    • 2010
  • Cheonan, Republic of Korea Navy patrol ship sank had happened by an unknown incident in the vicinity of Baekryeongdo southwest 1.6km(1 mile) sea at 21:45 on March 26, 2010. In terms of coastal researcher's point of view, it is meaningful to provide the sea condition of basic data necessary for search and rescue, more detailed predictions and inference data through the numerical simulations. Thus, in this study, we investigated the weather, wave, tide, tidal current, bottom soil conditions, and suspended sediment are investigated at the coast of Baekryeong-Daechung islands. And based on these data, the characteristics of sea conditions were analyzed. The tidal period at the time of incident corresponds between neap tide to mean tide. Until April 3-4 after March 26, the date of incident, the strongest velocity was progressed towards the spring tide. Thus, it was considered to be difficult to search and rescue operations. Also, because the ebb tide was in progress during 21:00 to 22:00, mass transport seems to be prevailed to the southeast. In particular, as the sudden turbulence due to the irregular topography existed was anticipated, we had carried out particle tracking experiment. From this experiment, depending on the situation of flow, the initial movement of the particles were directed to the southeast but it turned out moving towards the offshore based on the long term prediction. Through this result, it is considered that the scope of the search operation should be expanded towards the open sea.

Explaining Variance in Children's Recall of a Stressful Experience: Influence of Cognitive and Emotional Individual Differences (스트레스적 경험에 대한 아동 기억의 신뢰성과 인지 및 정서적 개인차 특성들과의 관계)

  • Seungjin Lee
    • Korean Journal of Culture and Social Issue
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    • v.19 no.3
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    • pp.343-365
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    • 2013
  • This study examined the effects of various individual differences on children's memory of a stressful experience. The participants for the current study were children (N=85) aged 4-9 years those who experienced a naturally occurring stressful experience from a dental procedure. There was overall negative relation between the level of stress and children's memory performance. However, more interestingly, the results of this study provided some further evidence that several cognitive (i.e., receptive language ability and working memory capacity) and emotional (i.e., children's general anxiety condition, children's self-report of pain and anxiety about the event) individual difference factors were associated with variations in children's remembering across ages. The results suggest that the relation between stress and children's memory might be impacted in part by children's various individual characteristics. Furthermore, the findings are discussed in the applied context that based on the results clinical and legal professionals can tailor interviews to best meet children's needs and capabilities, and create developmentally and individually sensitive guidelines for interviewing children in the legal system.

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A Crisis in Public Broadcasting of South Korea A Perspective from the Case of the So-called "Paik Jong-moon's Taped Conversation" at MBC with a Focus on the Press Control by Political Power (MBC '백종문 녹취록' 사건으로 본 공영방송의 위기 정치권력의 언론 통제 기제를 중심으로)

  • Kim, Sang Gyoon
    • Korean journal of communication and information
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    • v.81
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    • pp.189-224
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    • 2017
  • The case of 'Paik Jong-moon's Taped Conversation,' has presented "an important and serious challenge to the freedom of the press and democracy" in South Korea. Nevertheless, this case has not been reported by the mainstream news media. It has also been forgotten without a proper fact-finding or investigation by regulatory agencies, like The Foundation for Broadcast Culture, The Korea Communications Commission, or The National Assembly. This study aims to examine why the above has happened through in-depth interviews of reporters and TV producers, senior journalists, former and incumbent commissioners of the broadcasting regulatory agencies, and experts of the industry, as well as literature research. Here, I present three answers. First, I found two reasons the mainstream press has ignored this incident. 1) It serves for political interests instead of reporting truth. 2) Public broadcasters' watchdog role has been neutralized. Second, regulatory agencies like The Foundation for Broadcast Culture, The Korea Communications Commission and The National Assembly are ruled by political tribalism. The ruling party's members of the National Assembly and these agencies were reluctant to investigate allegations surrounding Paik Jong-moon, such as illegal dismissals, illegal intervention in programming or production, illegal recruitment and illegal business deals. That's because they considered CEO Paik an ally. Using their majority power, they have rejected the request from opposition-affiliated commissioners or from opposition lawmakers to investigate the allegations. Third, there were no alternative forces within the public broadcasters to unveil the truth. In conclusion, the legal and institutional shake-up of corporate governance is urgently needed for public broadcasters and broadcasting regulatory agencies.

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Analysis of Leaf Node Ranking Methods for Spatial Event Prediction (의사결정트리에서 공간사건 예측을 위한 리프노드 등급 결정 방법 분석)

  • Yeon, Young-Kwang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.4
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    • pp.101-111
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    • 2014
  • Spatial events are predictable using data mining classification algorithms. Decision trees have been used as one of representative classification algorithms. And they were normally used in the classification tasks that have label class values. However since using rule ranking methods, spatial prediction have been applied in the spatial prediction problems. This paper compared rule ranking methods for the spatial prediction application using a decision tree. For the comparison experiment, C4.5 decision tree algorithm, and rule ranking methods such as Laplace, M-estimate and m-branch were implemented. As a spatial prediction case study, landslide which is one of representative spatial event occurs in the natural environment was applied. Among the rule ranking methods, in the results of accuracy evaluation, m-branch showed the better accuracy than other methods. However in case of m-brach and M-estimate required additional time-consuming procedure for searching optimal parameter values. Thus according to the application areas, the methods can be selectively used. The spatial prediction using a decision tree can be used not only for spatial predictions, but also for causal analysis in the specific event occurrence location.