• 한국시뮬레이션학회논문지
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• 제12권4호
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• pp.73-81
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• 2003

An Ad Hoc network is a dynamic multi-hop wireless network that is established by a group of mobile hosts on a shared wireless channel by virtue of their proximity to each other. Since wireless transmissions are locally broadcast in the region of the transmitting host, hosts that are in close proximity can hear each other and are said to be neighbors. The transitive closure of the neighborhood of all the hosts in the set of mobile hosts under consideration forms an Ad Hoc network. Thus, each host is potentially a router and it is possible to dynamically establish routes by chaining together a sequence of neighboring hosts from a source to a destination in the Ad Hoc network. In a network, various real-time services require the network to guarantee the Quality of Services provided to the receiver. End-to-end QoS can be provided most efficiently when each layer of the protocol stack translates the requirements of the application into layer classified requirements and satisfies them. In this study, a mechanism to guarantee the QoS in Ad Hoc networks with buffer nodes is proposed. They effectively prevent traffic congestion and yield better transmission rate. In this way QoS is enhanced.

• Journal of Information Technology Applications and Management
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• 제20권3_spc호
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• pp.219-230
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• 2013

Real time accessiblity and agility in Ubiquitous-commerce is required under ubiquitous computing environment. The Research has been actively processed in e-commerce so as to improve the accuracy of recommendation. Existing Collaborative filtering (CF) can not reflect contents of the items and has the problem of the process of selection in the neighborhood user group and the problems of sparsity and scalability as well. Although a system has been practically used to improve these defects, it still does not reflect attributes of the item. In this paper, to solve this problem, We can use a implicit method which is used by customer's data and purchase history data. We propose a new clustering method of weighted preference for customer using k-means clustering and Bayesian network in order to improve the accuracy of recommendation. To verify improved performance of the proposed system, we make experiments with dataset collected in a cosmetic internet shopping mall.

• 한국지능시스템학회논문지
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• 제7권4호
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• pp.29-39
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• 1997

A discrete model reference control scheme for a vehicle four wheel steering system(4WS) is proposed and evaluated for a class of discrete time nonlinar dynamics. The schmen employs a neural network to identify the plan systems, wher the neural network estimates the nonlinear dynamics of the plant. The algorithm is proven to be globally stable, with tracking errors converging to the neighborhood of zero. The merits of this scheme is that the global system stability is guaranteed. Whith thd resulting identification model which contains the neural networks, the parameters of controller are adjusted. The proposed scheme is applied to the vehicle active four wheel system and shows the validity and effectiveness through simulation. The three-degree-of freedom vehicle handling model is used to investigate vehicle handing performances. In simulation of the J-turn maneuver, the yaw rate overshoot reduction of a typical mid-size car is improved by 30% compared to a two wheel steering system(2WS) case, resulting that the proposed scheme gives faster yaw rate response andl smaller side slip angle than the 2WS case.

• 제어로봇시스템학회논문지
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• 제7권8호
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• pp.647-655
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• 2001

In adaptive neuro-control, neural networks are used to approximate unknown plant nonlinearities. Until now, most of the studies in the field of controller design for nonlinear system using neural network considers the affine system with fixed number of neurons. This paper considers nonaffine nonlinear systems and on-line variation of the number of neurons. A control law and adaptive laws for neural network weights are established so that the whole system is stable in the sense of Lyapunov. In addition, at the expense of th input, tracking error converges to the arbitrary small neighborhood of the origin. The efficiency of the proposed scheme is shown through simulations ofa simple nonaffine nonlinear system.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.218-226
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• 2019

The use of Information and Communication Technologies (ICT) is the key to operate a change from the traditional manual reading of water meters and sensors to an automated system where high frequency data is remotely collected and analyzed in real time, one of the main components of a Smart Water Grid. The recent boom of ICT offers a wide range of both wired and wireless technologies to achieve this objective. We review and present in this article the most widely recognized technologies and protocols along with their respective advantages, drawbacks and applicability range which can be Home Area Network (HAN), Building Area Network (BAN) or Local/Neighborhood Area Network (LAN/NAN). We also present our findings and we give recommendations on the application of ICT in Smart Water Grids and future work needed.

• 한국항해항만학회지
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• 제43권5호
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• pp.273-280
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• 2019

This study developed an optimization model, defined as the IPS (Itinerary for Passenger Satisfaction), for a cruise ship to identify an itinerary that maximizes passenger satisfaction. A 0-1 integer programming model was developed to provide an optimal sequence of ports of call, assigning a destination to each day of the cruise. The concepts of the destination access network and the neighborhood of a destination were designed and manipulated to organize the complex network of destinations so that each next destination is selected within a practical overnight sail. The developed model can also be viewed as a reduced variant of the traveling salesperson problem with less constraints. A set of example tests shows that practical scenarios of the IPS with moderate cruise duration can be easily solved with light computation loads. Considering cruise ship passengers usually make their decisions not relying on only one destination but on an itinerary in its entirety, the purpose of this study was to identify itinerary alternatives to attract potential cruise passengers for attaining maximum occupancy level.

• 한국경제지리학회지
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• 제24권4호
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• pp.425-445
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• 2021

본 연구는 지역별로 주민 삶의 만족도에 영향을 주는 요인들을 도출하여 향후 도시재생사업의 활성화 방안에 대한 정책적 시사점을 제시하는 것이 목적이다. 이를 위해 서울시 근린재생 일반형 도시재생사업을 실시하는 창신·숭인동, 해방촌, 가리봉동 지역을 사례로 하여 설문조사를 진행하고 다중회귀분석을 하였다. 분석 결과 창신·숭인동에서는 로컬 거버넌스 요소 중 자율성, 가리봉동에서는 자율성과 네트워크가 증가할 때 주민 삶의 만족도가 상승하는 것으로 나타났다. 각 지역별로 지역재생역량의 요인을 살펴보면, 지역정체성은 세 지역 모두 경관적 특성이 주민 삶의 만족도에 미치는 영향이 크게 나타났다. 지역공동체는 창신·숭인동의 경우 개인역량, 가리봉동의 경우 참여역량, 관계역량이 증가할 때 주민 삶의 만족도가 상승하는 것으로 나타났다. 지역자산은 세 지역 모두 자연적 자산과 사회적 자산이 주민 삶의 만족도에 미치는 영향이 크게 나타났다. 따라서 근린재생 일반형 도시재생사업에서 주민 삶의 만족도의 영향관계는 도시재생사업을 추진하는 데 있어서 의미 있는 자료가 될 것으로 판단된다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권3호
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• pp.163-172
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• 2016

Electric load forecasting is essential for effective power system planning and operation. Complex and nonlinear relationships exist between the electric loads and their exogenous factors. In addition, time-series load data has non-stationary characteristics, such as trend, seasonality and anomalous day effects, making it difficult to predict the future loads. This paper proposes a locally-weighted polynomial neural network (LWPNN), which is a combination of a polynomial neural network (PNN) and locally-weighted regression (LWR) for daily shortterm peak load forecasting. Model over-fitting problems can be prevented effectively because PNN has an automatic structure identification mechanism for nonlinear system modeling. LWR applied to optimize the regression coefficients of LWPNN only uses the locally-weighted learning data points located in the neighborhood of the current query point instead of using all data points. LWPNN is very effective and suitable for predicting an electric load series with nonlinear and non-stationary characteristics. To confirm the effectiveness, the proposed LWPNN, standard PNN, support vector regression and artificial neural network are applied to a real world daily peak load dataset in Korea. The proposed LWPNN shows significantly good prediction accuracy compared to the other methods.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 춘계학술발표대회
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• pp.1294-1296
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• 2007

The IEEE 802.11 DCF forces neighboring nodes of an active transmitter to switch into inactive state. This conservative nature brings frame latency at transmitter neighborhood. This work exploits the IEEE 802.11n Frame Aggregation scheme to allow simultaneous transmissions from nodes that are neighbors to each-other. This is accomplished by the synchronization of control and data transmissions in slots of fixed length. Proposed scheme reduces the frame latency and improves aggregated network throughput.

• 한국조경학회지
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• 제32권2호
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• pp.36-54
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• 2004

The disposition of public parks pursue proper distribution and hierarchy formations on the basis of the neighborhood units theory. However, problems like price of land has brought about a large gap between theories and real conditions. This paper examines the problems of the practical disposition and disposition standards of public parks to solve these contradictions with reference to examples in Japan metro-cities. Study results are as follows; 1) The existing disposition theories are based on the district-boundary of men’s acting and settling down. Therefore, the disposition standards of large-scale parks or special parks beyond the humane scale have not been explained exactly. 2) As city sizes have expanded, these large-scale parks have developed greatly, however, they are located out of urban areas on the ground of nature’s geographical features. As a result, many small parks developed in urban areas. This extreme phenomenon of location would break up proper distribution and hierarchy. 3) Large parks over 4 ha not only take an important role in forming greenbelts but their location is also mainly based on their natural geographical features so that they are absorbed into the network -structure of greenbelts. 4) It is suggested that in planning parks, location and size of large parks over 4 ha should be selected and decided in the relation not with parks but with greenbelts. Parks of 4 ha or below are properly disposed. Also, these parks take a great role in forming the district boundary for settling down. Accordingly, proper distribution and hierarchy formation needs to be based on established neighborhood as they were previously.