• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권12호
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• pp.5442-5463
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• 2016

Designing efficient routing protocols for a wireless sensor network with mobile sinks (mWSN) is a challenging task since the network topology and data paths change frequently as sink nodes move. In this paper, we design a novel lightweight reactive ring based routing protocol called R3, which removes the need of proactively maintaining data paths to mobile sinks as they move in the network. To achieve high packet delivery ratio and low transmission cost, R3 combines ring based forwarding and trail based forwarding together. To support efficient ring based forwarding, we build a ring based structure for a network in a way such that each node in the network can easily obtain its ring ID and virtual angle information. For this purpose, we artificially create a virtual hole in the central area of the network and accordingly find a shortest cycled path enclosing the hole, which serves as base ring and is used for generating the remaining ring based structure. We accordingly present the detailed design description for R3, which only requires each node to keep very limited routing information. We derive the communication overhead by ring based forwarding. Extensive simulation results show that R3 can achieve high routing performance as compared with existing work.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.973-979
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• 2001

Sliding mode control guarantees robustness in the presence of modeling uncertainties and external disturbances. However, this can be obtained at the cost of high control activity that may lead to chattering As one way to alleviate this problem a boundary layer around sliding surface is typically used. In this case the selection of controller gain, control ban width and boundary layer thickness is a crucial problem for the trade-off between tracking error and chattering. The parameter tuning is usually done by trail-and-error in practice causing significant effort and time. An auto tuning method based on fuzzy rules is proposed in the paper in this method tracking error and chattering are monitored by performance indices and the controller tunes the design parameters intelligently in order to compromise both indices. To demonstrate the efficiency of the propose method a mass-spring translation system and a roboic control system are simulated and tested It is shown that the proposed algorithm is effective to facilitae the parameter tuning for sliding mode controllers.

• 한국정밀공학회지
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• 제15권11호
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• pp.39-45
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• 1998

Gas springs have been widely used in motor vehicles as well as in most areas of industry. Instead of coil springs, these gas springs are easily opreated to open(extension process) or close (compression process) the doors because $N_2$ gas with high pressure and oil are charged in tube. Most of manufacturers are using the trial ＆ error method in order to decide its specification(reaction force, damping force), which tends to waste time and money. Therefore, gas springs have been improved by properly changing the control pressure of $N_2$ Gas with its mounting location and weight to maximize its effect and to minimize its space. Although it has been researched on damping structure to minimize impact which is applied to vehicle when its back door is fully opened, the characteristics of damping structure are not known clearly. There(ore, this paper will not only clearly define the effect of important factors(open ＆ close force)for gas springs through theoretical analysis but also provide optimum design specification through development of program to avoid traditional method of specification determination such as the trail It error method which is widely used in whole industries including automotive industry.

• Educational Technology International
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• 제9권2호
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• pp.97-121
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• 2008

The purposes of the present study are to describe the design of mobile learning scenarios based on learning sciences theories, and to discuss implications for the future research in this area. To move beyond mere speculations about the abundant possibilities of mobile learning and to make real impact in K-12 school settings, it is critical to conduct school-based research grounded on the learning sciences theories. Towards this end, this paper describes school-based mobile learning projects conducted by a research team at the Learning Sciences Lab in Singapore, and then discusses the possibilities and challenges of mobile learning to further inform future research. Specifically, this paper explores the affordances of mobile technology, such as portability, connectivity and context-sensitivity, to design seamless learning scenarios that bridge formal and informal learning experiences. The authors present a framework for re-conceptualizing different types of learning based on physical settings and intentionality, and then describe two seamless learning scenarios, namely 3Rs and Chinatown Trail, which were implemented in one primary school in Singapore. In conclusion, the authors discuss the affordances of seamless mobile learning for enhancing one's lived experiences to build a living ecological relationship between the person and the environment, and how mobile technology can play a critical role for enabling such lived experiences.

• 한국실내디자인학회논문집
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• 제22권5호
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• pp.11-21
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• 2013

The development of modern industry and the production of new materials of architecture have recognized as an important aspect. This study intended to discuss about the meaning of main elements of the architecture materials, its implications for properties, and, highlighted meaning of the properties of modern interior design. The purpose of this study is to analyze the case studies of Place and Physical materials of synaesthesia of modern architecture as well as modern architecture is not only concentrated in the visual aspect but also the larger ramifications of sensory. Synesthesia in architectural space can be called experiential existence that built in the space of human perception and based on the human emotion that targeted by physical architectural space. Accordingly, these case studies are to consider about how the materials being passed by any effect in a modern interior space presented, In order to find the essential meaning in modern interior space, this studies focused on Swiss architect Peter Zumthor's cases. Following analyze of Peter Zumthor's place of architectural space and materials, this study structured by the six kinds of synesthesia characters. First, time and remember to infer changes, Second, traditional and regional ingredients involve the substitution of one empirical space, Third, non-materiality through the neutralization, Fourth, auditory memory through the embodiment of everydayness, Fifth, trail through the sense of smell for the presence, Sixth, the relationship of natural and industrial products. Peter Zumthor's characteristics of these works are result of factors on the synesthetic relationship with the human response to architecture, the five senses, memories, experiences, and temperature. Also it is a synesthetic result of all human emotion to clarify of the architecture materials and non-material mediums by which light by a compound.

• 복식문화연구
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• 제30권3호
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• pp.366-380
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• 2022

This study aims to develop the designs and patterns of yoga tops that are better adjusted to suit females in their 30s and 40s. After conducting a comparative analysis of three different popular yoga garments, one yoga top currently on the market was selected. Subsequently, a fit evaluation was conducted on Trail 1-garment α, which was developed body analysis performed based on selected yoga top C, followed by the production of the Trial 2 garment after making adjustments according to the comparative observation results. Based on these results, garment C with the longest top length was evaluated as the best. The results of the evaluation of appearance and fit conducted of Trial 1-garment α compared to those of C showed that Trial 1-garment α was superior in both evaluations. Trial 2-garment β was produced after making improvements on Trial 1-garment α and then placed under identical comparative evaluation condition as Trial 1-garment α. Results showed a significant improvement compared to Trial 1-garment α, and the Trial 2 garment with an additional arm pattern was shown to be superior in shoulder strap width stability, shoulder strap pressure, chest stability, degree of waist pressure, waist comfort, general fitting, and supportiveness.

• 한국농촌건축학회논문집
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• 제20권1호
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• pp.1-10
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• 2018

In order to give back-to-farm residents the stable settlement environment in the rural area, the 'community village' is desirable as the village type and its village planning guideline should be supported as well. The purpose of this study was to develop a guideline for the planning of back-to-farm community village in the living and social environmental aspects, based on the comprehensive comparative analysis about items that field survey and literature suggested. The guideline for the living environment was developed for 6 items; village structure(adequate size, lot, outer space for household), village landscape(allocation, space composition), road system and transportation(parking lot in village, placement of bus stops, village trail, public transportation, road and pedestrian system), common living facilities and common space(number, size, location & placement, plan type, planning type of common facilities), transfer space, individual housing(type, size, planning type). The guideline for the social environment was developed for 3 items; village making and establishment(resident participation type, resident participation tool, residents' construction participation) and resident education in the course of planning, resident participation(gathering resident opinion, decision making, composition of construction committee, community newsletter).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1594-1597
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• 2005

A rapid development and a wide use of the Internet have expanded a network environment. Further, the network environment has become more complex due to a simple and convenient network connection and various services of the Internet. However, the Internet has been constantly exposed to the danger of various network attacks such as a virus, a hacking, a system intrusion, a system manager authority acquisition, an intrusion cover-up and the like. As a result, a network security technology such as a virus vaccine, a firewall, an integrated security management, an intrusion detection system, and the like are required in order to handle the security problems of Internet. Accordingly, a router, which is a key component of the Internet, controls a data packet flow in a network and determines an optimal path thereof so as to reach an appropriate destination. An error of the router or an attack against the router can damage an entire network. This paper relates to a method for RSMS (router security management system) for secure networking based on a security policy. Security router provides functions of a packet filtering, an authentication, an access control, an intrusion analysis and an audit trail in a kernel region. Security policy has the definition of security function against a network intrusion.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1351-1354
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• 2005

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. Korean High Speed Train has been developed by KRRI for last 7 years to satisfy the need. Korean High Speed Train (350km/h), composed of 2 power cars, 2 motorized car and 3 trailer cars, has been developed and is under trial test. To verify the design requirements for the functions and traction performances of the train, KRRI (Korea Railroad Research Institute) decided to evaluate traction performances of the train during trial test. For this purpose, torque, velocity, voltage and current must be measured. KRRI has developed a measurement system that can measure vast and various signals effectively. In this paper, we introduce traction performances of Korean High Speed Train. The traction measurement items are focused on the verification of motor block performances. Motor block consists of 2 motors. By this test, we verified traction performances of Korean High Speed Train

• 한국환경생태학회지
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• 제19권2호
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• pp.106-111
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• 2005

월악산국립 공원지역의 탐방로 주연부식생 구조를 파악하기 위하여 주요 탐방로 5개 구간에 조사구 39개를 설치하여 식생 구조를 조사하였다. 탐방로별 교목층의 우점종은 신갈나무와 소나무, 굴참나무가 조사되었으며, 관목층의 주요 수종으로는 입지환경 요인이나 이용강도에 상관없이 동창구간을 제외한 모든 구간에서 조록싸리로 나타났다. 5개 탐방로 구간 간 유사도지수는 $41.65\%\~66.50\%$로 나타났다. 입지환경별 탐방로 주연부 수종의 차이는 크게 나타나지 않는 것으로 판단된다.