• Journal of Institute of Control, Robotics and Systems
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• v.11 no.3
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• pp.254-261
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• 2005

Time-optimal performances are analyzed in the sense of inner loop. A varying-time sharing thrusting logic is suggested as a new sequential paired thrusting logic for fast maneuvers of satellites with coupled thruster configuration. Its time-optimal maneuvering performance is compared with two conventional thrusting logics: separate thrusting logic and constant-time sharing sequential paired thrusting logic. It is found that the newly suggested varying-time sharing thrusting logic can be easily implemented by adjusting the conventional constant-time logic with its thrust on-time, while it can reduce the maneuvering time enormously as much as the separate thrusting logic. The performance of the logic is simulated on the agile maneuvering spacecraft model KOMPSAT-II.

• Journal of Family Resource Management and Policy Review
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• v.15 no.2
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• pp.103-128
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• 2011

The purpose of this study is to analyze the family sharing time of housework and to examine the sharing time with family is influenced by socio-demographic variables. The Time Use Survey data collected by Korean National Statistical Office in 2009 is used. Among the total sample of 21,000 individuals, 9,179 samples who are married, aged from 20 to 59 years old and non-farmers are selected for analysis. The statistical methods are frequency, percentage, crosstabulation, t-test, and regression analysis. The following is a summary of the major findings. First, comparison of men and women shows women spend more time on housework than men do. But sharing housework time with family for men increase on Sunday. Performer average is almost same in men and women. Secondly, the family sharing time on housework is longer on Sunday. It is due to increase of men's family sharing time. It means that men's time substitute for women's housework. Thirdly, the influencing factors on family sharing housework are gender, age, education, presence of spouses, monthly income, dual earner status, weekly working hours, gender role atittude and presence of preschoolers. Family sharing housework is not only household labor but also family pleasure time. It means family policy should focus on making family time for workers fundamentally. And family policy needs to make a system of educational program for work-family balance.

• Journal of Computing Science and Engineering
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• v.6 no.4
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• pp.287-293
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• 2012

We introduce a methodology for the study of the application-level performance of time-sharing parallel jobs on a set of compute nodes in high performance clusters and report our findings. We assume that parallel jobs arriving at a cluster need to share a set of nodes with the jobs of other users, in that they must compete for processor time in a time-sharing manner and other limited resources such as memory and I/O in a space-sharing manner. Under the assumption, we developed a methodology to simulate job arrivals to a set of compute nodes, and gather and process performance data to calculate the percentage slowdown of parallel jobs. Our goal through this study is to identify a better combination of jobs that minimize performance degradations due to resource sharing and contention. Through our experiments, we found a couple of interesting behaviors for overlapped parallel jobs, which may be used to suggest alternative job allocation schemes aiming to reduce slowdowns that will inevitably result due to resource sharing on a high performance computing cluster. We suggest three job allocation strategies based on our empirical results and propose further studies of the results using a supercomputing facility at the San Diego Supercomputing Center.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.179-185
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• 2005

This paper presents a novel circuit topology of a high efficiency single-phase power conditioner. This power conditioner is composed of time-sharing sinewave absolute pulse width modulated boost chopper with a bypass diode in the first power processing stage and time-sharing sinewave pulse width modulated full-bridge inverter in the second power processing stage operated by time-sharing dual mode pulse pattern control scheme. The unique operating principle of the two power processing stage with time-sharing dual mode sinewave modulation scheme is described with a design example. This paper proposes also a sinewave tracking voltage controlled soft switching PWM boost chopper with a passive auxiliary edge-resonant snubber. The new conceptual operating principle of this novel power conditioner related to new energy utilization system is presented and discussed through the experimental results.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.5 no.1
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• pp.04-10
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• 1987

We consider a time sharing computer system with a single processor where tasks ofK different types arrive at the system according to independent time homogeneous Poisson processes from outside. A task, after given a quantum for processing, leaves the system, or changes the type and rejoins the system according to specified probabilitycs. While many existing priority time sharing models determine the priorities of tasks strictly by their service time requirements, this paper develops a new scheduling rule wherein the importances or urgencies in addition to the service time requirements of tasks are counted, by inposing an appropriate reward structure on the system. Also presented is the algorithm through which to determine the rankings of K types according to this new scheduling rule.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.193-198
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• 2004

We propose and analyse a flexible secure file sharing scheme which can be used for data sharing among members in P2P environment. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient memory management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.1-11
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• 2021

Development of ICT technologies leads exponential growth of various sharing economy over the last couple of years. The intuitive advantage of the sharing economy is efficient utilization of idle goods and services, but there are safety and security concerns. In this paper, we propose a onetime password based access control system to support secure accommodation sharing service and show the implementation results. To provide a secure service to both the provider and the user, the proposed system issues a onetime access password that is valid only during the sharing period reserved by the user, thereafter access returns to the accommodation owner. Especially, our system provides secure user access by merging the two elements of speaker recognition using voice and a one-time password to open and close the door lock. In this paper, we propose a secure system for accommodation sharing services as a use-case, but the proposed system can be applicable to various sharing services utilizing security-sensitive facilities.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.342-345
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• 2003

Due to the rapid development of manufacturing and information technology, traditional supply chain scheme has been changed dramatically Most companies have been forced to relocate or redesign their logistics network in different countries. A supply chain partnership is a relationship formed between two independent members in supply chain through information sharing to achieve specific objectives and benefits in terms of reductions in total costs and inventories. This study illustrates the benefits of supply chain partnerships based on information sharing and lead-time patterns. We consider three level of information sharing: (1) immediate order information; (2) demand information; (3) inventory information. Given a fixed total lead-time, how lead-time distribution will affect the bullwhip effect and inventory cost under information sharing strategies. The results can help improving supply chain performance and selecting suitable direction for the re-configuration of supply chain network.

• Journal of Families and Better Life
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• v.21 no.1
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• pp.61-72
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• 2003

This study examines the problematic fact that most housewives are excluded from receiving the benefits of the National Pension Plan in South Korea. The National Pension Plan assigns no value to housework or household production, which in turn discourages full-time housewives from participating voluntarily in the Plan. In this article, I propose to utilize Credit Splitting and Pension Sharing in order to take into account full-time housewives' economic contribution in the National Pension Plan. In this article, I also discuss the ranges and application methods of the Credit Splitting and Pension Sharing. For this study, I have analyzed the data of 11,967 unemployed married women living with spouses published in“Research Data on Everyday Life Time Usage”by the Korea National Statistical Office in 1999. The value of the full-time housewives' labor varies depending on the methods of estimation. However, all estimated values exceed the average value assigned to the housewives by the National Pension Corporation. It is clear that full-time housewives' unpaid labor contributes a great deal to the formation of household property and wealth, which is a valid reason for Pension Sharing and Credit Splitting. This article also provides logical factors to consider in the process of Pension Sharing and Credit Splitting, which can be used for developing computerized software to determine a full-time housewives' labor value at the time of divorce or for any other purpose.

• Journal of Korea Multimedia Society
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• v.23 no.3
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• pp.499-507
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• 2020

This paper is one of the types of 'sharing economy', a social economic model that borrows and shares things, spaces, and services from the development of the 4th Industrial Revolution. Through sharing of empty space and time in the city, I would like to suggest a way to reduce the closure of small business owners in order to create jobs, which is one of urban problems in the community. We also build a platform that utilizes the free time and space of buildings through space sharing, one of the types of sharing economy, and provides education programs for start-up education, promotion, marketing, and consulting by matching small business owners with building owners. Therefore, in this paper, by sharing the space and time, the landlord and the small business can share the profits of the small business by reducing the business owner's closure and the job creation plan. Coaching urban regeneration was proposed.