• Title/Summary/Keyword: 공간 복잡도

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Optimal Berth and Crane Scheduling Using Constraint Satisfaction Search and Heuristic Repair (제약만족 탐색과 휴리스틱 교정기법을 이용한 최적 선석 및 크레인 일정계획)

  • 류광렬;김갑환;백영수;황준하;박영만
    • Journal of Intelligence and Information Systems
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    • v.6 no.2
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    • pp.1-14
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    • 2000
  • The berth and crane scheduling problem in a container terminal encompasses the whole process of assigning berth to each ship, determining the duration of berthing, assigning container cranes to each ship, and determining the specific start and end time of each crane service, for all the ships scheduled to be arriving at the terminal during a certain scheduling horizon. This problem is basically a constraint satisfaction problem in which cranes and berths should be assigned in such a way that all the spatial and temporal constraints are satisfied without any interference. However, it is also an optimization problem because the requested arrival and departure time should be met for as many of the scheduled ships as possible, while the operation cost of the terminal should be minimized. In this paper, we present an effective and efficient approach to solving this type of problem, which combines constrain satisfaction search and heuristic repair. We first employ a constraint satisfaction search to find a feasib1e solution. Then, the feasible solution is modified to a more optimal one by iteratively applying our heuristic repair operations within the framework of constraint satisfaction search. Experimental results with a real data from Pusan East Container Terminal showed that our approach can derive a schedule of satisfactory quality in a very short time.

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An IoT Tag and Social Message-based Device Control System (IoT 태그 및 소셜 메시지 기반 사물 제어 시스템)

  • Baek, Seung Min;Jin, Yeon Ju;Ha, Kwon Woo;Han, Sang Wook;Jeong, Jin-Woo
    • KIISE Transactions on Computing Practices
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    • v.23 no.9
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    • pp.550-556
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    • 2017
  • Due to the rapid growth and development of Internet of Things (IoT), various devices are now accessible and controllable anytime from anywhere. However, the current IoT system requires a series of complex steps (e.g., launch an application, choose a space and thing, control the thing, etc.) to control the IoT devices; therefore, IoT suffers from a lack of efficient and intuitive methods of interacting with users. To address this problem, we propose a novel IoT control framework based on IoT tags and social messages. The proposed system provides an intuitive and efficient way to control the device based on the device ownership: 1) users can easily control the device by IoT tagging, or 2) users can send an IoT social message to the device owner to request control of the tagged device. Through the development of the prototype system, we show that the proposed system provides an efficient and intuitive way to control devices in the IoT environment.

Study on Designing and Implementing Online Customer Analysis System based on Relational and Multi-dimensional Model (관계형 다차원모델에 기반한 온라인 고객리뷰 분석시스템의 설계 및 구현)

  • Kim, Keun-Hyung;Song, Wang-Chul
    • The Journal of the Korea Contents Association
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    • v.12 no.4
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    • pp.76-85
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    • 2012
  • Through opinion mining, we can analyze the degree of positive or negative sentiments that customers feel about important entities or attributes in online customer reviews. But, the limit of the opinion mining techniques is to provide only simple functions in analyzing the reviews. In this paper, we proposed novel techniques that can analyze the online customer reviews multi-dimensionally. The novel technique is to modify the existing OLAP techniques so that they can be applied to text data. The novel technique, that is, multi-dimensional analytic model consists of noun, adjective and document axes which are converted into four relational tables in relational database. The multi-dimensional analysis model would be new framework which can converge the existing opinion mining, information summarization and clustering algorithms. In this paper, we implemented the multi-dimensional analysis model and algorithms. we recognized that the system would enable us to analyze the online customer reviews more complexly.

Discussion to Spatial Characteristics on a Sub-tidal Benthic Community Composed to the Complicated Coastal Lines Around Tongyeong, Korea (복잡한 해안선 구조를 가진 통영 해역에서 조하대 저서생물 군집의 공간특성 비교)

  • Yoon, Kon-Tak;Jung, Yun-Hwan;Kang, Rae-Seon
    • Ocean and Polar Research
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    • v.32 no.2
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    • pp.123-135
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    • 2010
  • Around Tongyeong coasts which located in southern coast of Korea composed to the complex coastal line and scattered by small islands. It also has been distributed to a complicated bathymetric structure by several types of channels. This study carried to analyze the spatial characteristics of macrobenthic community and benthic environmental variance on sub-tidal area based on multivariate statistics tools. Sediment composition varied from muddy sand to mud, and along the channels, it composed to a heterogeneous bottoms mixed by shell fragment, cobbles and mud. Organic contents on the surface sediment varied 1.1-3.9%. Total of 272 species, $33,349\;ind./m^2$ of macrobenthos identified in all of sample area. Polychaetes also prevailed among the specimen. L. longifolia, P. pinnata dominated based on density. Considering on the biomass, echinoderm S. lacunosa, A. tricoides listed. Closer to the coastal area, the density and diversity were higher. Community structure based on cluster analysis was discriminated into three groups. Each group was also characterized by geographical state such as depth, sediment composition. In addition, when applied to the bathymetric data, the channel, which composed to the mixed sediment, made a role of limited factor which characterized to benthic community. Because the specimen around the channel have been affected on the diverse sediment mixture. Most of benthic studies in the southern coast of Korea focused to the condition of benthic organic pollution spatially, because along the coast, it also developed a aquaculture ground and industrial complex. But, as results, most of the area, it turn out the less polluted areas nevertheless similar environment situation. It supposed that benthic community affect to the bottom sediment composition by physical characteristics.

Electrical Resistivity Survey for Hydrologic Monitoring in the Gwang-neung Experimental Forest - Preliminary Results (광릉 소유역의 수문 관측을 위한 전기비저항탐사 - 예비결과)

  • Choi In-Hyuk;Moon Sang-Ki;Woo Nam-Chil;Kim Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.1
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    • pp.98-106
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    • 2005
  • Groundwater plays an important role in water and carbon cycles in Gwangneung forest watershed located in a complex landscape. Because groundwater affects electrical resistivity (ER) of underground materials, the depth to water table and water content in subsurface can be investigated through measuring ER. Accordingly, the ER survey has been employed more frequently in recent hydrological investigations. Quantitative applications of the results of ER survey will contribute significantly to the examination of water budget closure at various spatiotemporal scales. This paper presents the preliminary results of the ER survey conducted at Gwangneung forest watershed to determine proper locations and depths of monitoring wells. Such use of ER survey, in conjunction with an integrated geophysical investigation and geographic information system, can provide more effective examination of underground structure and optimal locations of monitoring wells to further our understanding of the role of groundwater.

A Study of Intention to Use Wrist-worn Wearable Devices Based on Innovation Resistance Model - Focusing on the Relationship between Innovation Characteristics, Consumer Characteristics, and Innovation Resistance (혁신저항 모형에 기반한 손목형 웨어러블 디바이스의 수용의도 연구 - 혁신특성, 소비자 특성, 혁신저항을 중심으로)

  • Shin, Jae-Gwon;Lee, Sang-Woo
    • The Journal of the Korea Contents Association
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    • v.16 no.6
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    • pp.123-134
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    • 2016
  • As the internet of things has come into the spotlight, wearable devices have been emerging as a new and growing market and the next hot thing in the world. However, wearable device growth in the market has not met expectations. For continued growth and diffusion of wearable devices, it is important to investigate user resistance factors to them. This study gives attention to people who have resistance to wearable devices' tendency towards innovative uses. Specifically, this study is intended to find out which factors influence consumers' resistance and intention to use wrist-worn wearable devices, which are in high demand among wearable device. Results of the study show that the relative advantage, innovation expectation, complexity, financial risk and physical risk are the predictors of innovation resistance on wrist-worn wearable devices. And consumers' resistance affects the intention of positive acceptance. These findings confirm the importance of consumer resistance to the wrist-worn wearable device.

An Efficient Buffer Cache Management Algorithm based on Prefetching (선반입을 이용한 효율적인 버퍼 캐쉬 관리 알고리즘)

  • Jeon, Heung-Seok;Noh, Sam-Hyeok
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.5
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    • pp.529-539
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    • 2000
  • This paper proposes a prefetch-based disk buffer management algorithm, which we call W2R (Veighingjwaiting Room). Instead of using elaborate prefetching schemes to decide which blockto prefetch and when, we simply follow the LRU-OBL (One Block Lookahead) approach and prefetchthe logical next block along with the block that is being referenced. The basic difference is that theW2R algorithm logically partitions the buffer into two rooms, namely, the Weighing Room and theWaiting Room. The referenced, hence fetched block is placed in the Weighing Room, while theprefetched logical next block is placed in the Waiting Room. By so doing, we alleviate some inherentdeficiencies of blindly prefetching the logical next block of a referenced block. Specifically, a prefetchedblock that is never used may replace a possibly valuable block and a prefetched block, thoughreferenced in the future, may replace a block that is used earlier than itself. We show through tracedriven simulation that for the workloads and the environments considered the W2R algorithm improvesthe hit rate by a maximum of 23.19 percentage points compared to the 2Q algorithm and a maximumof 10,25 percentage feints compared to the LRU-OBL algorithm.

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An Experimental Study of Supersonic Underexpanded Jet Impinging on an Inclined Plate (경사 평판에 충돌하는 초음속 과소팽창 제트에 관한 실험적 연구)

  • 이택상;신완순;이정민;박종호;윤현걸;김윤곤
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.4
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    • pp.67-74
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    • 1999
  • Problems created by supersonic jet impinging on solid objects or ground arise in a variety of situations. For example multi-stage rocket separation, deep-space docking, V/STOL aircraft, jet-engine exhaust, gas-turbine blade, terrestrial rocket launch, and so on. These impinging jet flows generally contain a complex structures. (mixed subsonic and supersonic regions, interacting shocks and expansion waves, regions of turbulent shear layer) This paper describes experimental works on the phenomena (surface pressure distribution, flow visualization) when underexpanded supersonic jets impinge on the perpendicular, inclined plate using a supersonic cold-(low system. The used supersonic nozzle is convergent-divergent type, exit Mach number 2, The maximum on the plate when it was inclined was much larger than perpendicular plate, owing to high pressure recoveries through multiple shocks. Surface pressure distribution as to underexpanded ratio showed similar patterns together.

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Anatomy, Biomechanics and Physical Examination of Foot and Ankle (족부 및 족관절의 해부학, 생역학 및 신체 검사)

  • Hur, Chang-Yong;Kim, Hak Jun
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.3 no.1
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    • pp.32-37
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    • 2010
  • Ultrasonographic diagnosis and treatment in Orthopaedic fields had been widely used. Sonographic diagnosis and treatment of foot and ankle is convenient because of anatomical characteristics. The knowledge of the anatomy and biomechanics in foot and ankle area can help to diagnose and treat the disease around foot and ankle. 28 bone and many tendons, ligaments and muscles are consist of ankle and foot joint and the coordinative relation among these structures can allow the dual function, weight bearing and locomotion of ankle and foot during gait cycle. Foot and ankle have small room for many structures, so systemically physical examination is essential for diagnosis. Accurate understanding of foot and ankle anatomy and biomechanics could be helpful to using ultrasonograph.

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Automatically Registering Schedules from SMS Messages on Handheld Devices (휴대전화에서 단문 메시지로부터 일정 자동 등록)

  • Kim, Jae-Hoon;Kim, Hyung-Chul
    • Korean Journal of Cognitive Science
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    • v.22 no.1
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    • pp.1-18
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    • 2011
  • With rapid spread of handheld devices like cellular or smart phones, a short message service (SMS) comes on the public as a communication means. SMS is very cheap and can be easily written down on the storage in order not to forget it, hence it is widely used to inform schedules (time and place). In this paper, we develop a system for automatically registering schedules extracted from SMS text messages. SMS text messages are very short and concise, but include a lot of Internet words like slangs and abbreviations. These have made it difficult to extract information on schedules from them. Also handheld devices have some limitations on computing power and storage and then applying general natural language processing modules like morphological analysis to the devices are somewhat hard. To relax these burdens, we extract schedule informations from SMS messages using machine learning methods like condition random field (CRF) without using any language processing modules and register the informations on the schedule management system of handheld devices. Our proposed automatic schedule registration system has implemented on Samsung Omnia phone for experiments.

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