• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.544-551
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• 2011

This paper presents the circuit arrangement and effective control method of regenerative energy storage system for an electric vehicle using super-capacitors as the braking energy storage element. A bi-directional controlled current flow of the DC-DC converters with the capacitor bank is connected in parallel with battery, and is controlled so that the whole of the braking energy is effectively absorbed into the capacitors and released back to the electric motor upon acceleration. The converter needs the series-parallel switching circuit for making the best use of the series capacitors and for limiting the step-up ratio of the boost converter. The proposed methods are verified by computer simulation and experimental set-up. They are usefully applied to the electric vehicles such as green cars, electric motorcycles, bike, etc which are power- supplied by the electric batteries.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.273-279
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• 2000

Until recently performance requirements for automatic transmission fluids have continued to change to reflect the design changes of automatic transmission. The major purpose for these design changes is to improve the fuel economy and easy driving. To meet recent performance requirements fur automatic transmission the needs for special base oils Bike API Group III and IV base oils become larger. In this paper to evaluate the effects of base oils on performance of automatic transmission fluids formulated with API Group I,II,III and IV and Dexron III and Hereon Type additive package, Brookfield viscosity, oxidation test, SAE No.2 friction test and seal compatibility test were examined. From the test we knew that the use of Croup III and IV base oils in ATF has several benefits in low temperature viscosity, oxidation stability and SAE No.2 friction characteristics.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.149-162
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• 2015

This study was conducted on young children safety helmet to prevent risk of head injuries from external shock. Young children helmet shall be easy to wear and use comfortably. But the young children helmet market in domestic has imported dependently and widely variations in quality because the euro product of high priced and the east asia product of low priced are selling at the same time. Therefore, this study surveyed children under 13 years of age and Married people and studies their actual state of wearing. Furthermore, this study is going to propese the improving wearing of helmet and the major points of quality of helmet and the problem by comparing and reviewing regulations of domestic and foreign.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.773-775
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• 2013

본 논문은 USN 융합기술을 활용하여 u-city 또는 u-bike 등과 같은 시스템을 구축함에 있어서, 필수 구성요소인 USN 기반 센서 네트워크 게이트웨이를 설계하고 구현한다. 따라서 게이트웨이는 관리 대상인 사물에 대한 상황 인지 기능을 수행하기 위하여 상황 인지 처리 하드웨어를 포함하는 게이트웨이 제어부(MPU)와 상황인지 처리 Sink-Node간의 상호 연동 기능, IP 코어망을 통한 센서망 관리 운용 시스템 연동 기능 등을 포함한다. 개발된 게이트웨이는 현재 자전거 공용 시스템에 적용하여 운용되고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.754-756
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• 2013

건강, 운동에 관한 관심이 고조되고 레저를 즐기는 사용자층이 확대되어 감에 따라 다양한 종류의 레저형 시뮬레이터에 대한 개발이 이루어지고 있다. 그러나 단순 운동을 위한 스포츠 시뮬레이터는 흥미를 반감시켜 지속적인 운동에 대한 저해하는 요소가 된다. 본 논문에서는 이런 시뮬레이터의 한계를 극복하기 위해 다양한 콘텐츠를 접목시킨 스포테인먼트형 자전거를 제안한다. 이를 위해 개인 신체 정보를 입력을 통해 프로그램 추천 및 이력관리가 가능하고 흥미요소인 게임, 음악 등을 동시에 즐기면서 운동을 할 수 있는 자전거 시뮬레이터 UXBike 시스템 개발한다. 이는 보편화된 운동 레저 시뮬레이터와 콘텐츠의 융합을 통해 사용자의 몰입도 향상 및 지속적인 관심을 갖게 하는 계기가 될것이라 판단된다.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.27-34
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• 2023

This study conducted a study on a small-capacity PCS using lithium-ion batteries used in personal mobility. Most of the batteries in Personal Mobility only charge with external chargers and are used only as mobile energy sources. However, this paper aims to charge the battery of PM using PV and system power or to use the charged power as a stand-alone power supply. The developed PCS can be operated as a two-channel battery charger/discharger, a battery charger using solar power, and a stand-alone solar inverter depending on the operation method. The validity of the manufactured small-capacity PCS was verified through experiments.

• Review of KIISC
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• v.33 no.1
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• pp.51-58
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• 2023

차세대 컴퓨터인 양자 컴퓨터는 현재 정보화시스템에서 널리 사용되고 있는 공개키 암호 시스템인 RSA와 Elliptic Curve Cryptography (ECC)의 안전성을 위협하고 있다. 특히 양자 알고리즘인 Shor 알고리즘은 RSA와 ECC가 기반하고 있는 수학적 난제들을 다항 시간 내에 해결할 수 있기 때문에 NIST에서는 양자컴퓨터 상에서 내성을 가진 공개키 암호 표준화 공모전을 개최하였다. 2022년도에 NIST에서는 4개의 3라운드 최종 표준화 알고리즘을 발표하였다. 이와 동시에, 4라운드 표준화 알고리즘을 진행함으로써, 공개키 분야에서 코드 기반 또는 아이소제니 기반의 새로운 암호 알고리즘을 추가로 표준화할 예정이다. 이에 본 논문에서는 NIST 양자 내성 암호 표준화 공모전 4라운드의 후보 알고리즘인 코드 기반 암호 Classic McEliece, BIKE, HQC와 아이소제니 기반 암호 SIKE의 최신 동향에 대해 확인해본다. 추가적으로, 해당 암호 알고리즘에 대한 분석 기법과 공격 사례에 대해 살펴보고록 한다.

• Asia pacific journal of information systems
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• v.29 no.3
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• pp.407-413
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• 2019

This editorial on 'Smart Services and Internet of Things (IoT)' focuses on the topics related to the applications of IoT to consumer products and services, which have become 'smarter' thanks to IoT. This special issue explores, in different ways, the phenomena of smart services and the role of IoT in business innovation across different contexts such as product-service system, car auction, tourism industry, communicating platform, online travel agency, self-service retail, and bike sharing. We hope that this special issue will provide a significant step forward in enabling researchers and practitioners to understand smart services and IoT.

• Information Systems Review
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• v.18 no.1
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• pp.157-175
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• 2016

Under the market economy of capitalism, several limitations reveal the inequity and redistribution problem of wealth, inefficiency of over-manufacturing and over-consumption, pollution of the natural environment, and the constraint of human liberty and dignity. The new challenge of symbiotic relationships that encourage individual corporations coincides with the need to practice social responsibility and share values to overcome these limitations. Social economy and the social enterprises that simultaneously pursue the making of corporate private profits and the realization of social values have been suggested and disseminated as alternative social value creators. Furthermore, the concept of a sharing economy, which refers to the sharing of things rather than owning them, is growing traction as a new paradigm of capitalism. However, these efforts of social enterprises have fallen short against the conflicts between private profit and social values. This study deals with the case of a start-up social corporation, "Purun Bike Sharing Inc.," which is based on a regional sharing economy business model about bike rental services that use Information and Communication Technology (ICT). This corporation pursues harmonic management to achieve a balance between private profit and social value. Its corporate mission is to achieve sharing, coexistence, and contribution for public welfare. This mission is a possible idea for use in the local community network as a core key for sustainable social enterprises. The model can also be an alternative approach to overcome the structural friction in the social corporation. This study considers the case of Purun Bike Sharing as a sustainable way to practice a sharing economy business model based on a regional cooperation network, which can be combined with social value, and to apply ICT to a sharing economy system. It also examines the definition and current state of social enterprises and the sharing economy, and the cases of the sharing economy business model for the review of prior research.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.365-373
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• 2014

This study is to analyze the physical environment and conduct spatial data for bicycle road system in changwon. Index for evaluation index was developed based on literatures. Then the level of importance and weight have been modified through experts review. Finally, index with eight categories such as greenness(40% over), bicycle road connectivity(1.8, 9.8%), road type bike(bicycle lane, 24.4%), pave type(asphalt 72.5%), illegal parking(none, 93.9%), bike road surface visibility(exist, 46.8%), vehicle speed limits(30km, under), vehicle traffic(500/hr under, 44.3%) have been applied to empirical investigation. Collected data has been hierarchically classification by ArcGIS Program. The Highest grades(score 31-35, level 1) occupied 35% of target destination. High level of greenness and load type has contributed to high score. In addition, average level of greenness of those destination was 35% and higher, which provide high degree of security and freshness for bicycle riding. Meanwhile, lowest level(level 5, which earned 15 point or less) occupied 24.5%. illegal parking, low level of greenness, and no surface sign caused low score.