• Journal of Korea Multimedia Society
• /
• v.9 no.7
• /
• pp.827-834
• /
• 2006

In distributed virtual environment, system response time to users' interactions is an importance factor to determine the degree of contentment with the system. Generally, response time is affected by the efficiency of event message processing algorithm, and most of previous systems use FCFS algorithm, which processes message traffic sequentially based only on the event occurrence time. Since this method totally depends on the order of occurrence without considering the priorities of events, it has a problem that might drop the degree of system response time by causing to delay processing message traffic when a bottleneck phenomenon happens in the server side. To overcome this limitation of FCFS algorithm, this paper proposes a concurrent event scheduling algorithm, which is able to process event messages concurrently by assigning the priorities to the events. It is also able to satisfy the two goals of system together, consistency and responsiveness through the combination of occurrence time with priority concept of events.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.400-404
• /
• 2008

댐 군 연계운영을 위한 기존의 많은 최적화 모형은 경제성에 기반을 둔 단일 목적 함수를 가정함으로써 현실과는 동떨어진 결과를 도출하곤 하였다. 따라서 보다 현실적인 최적화 모형이 되기 위해서는 실제 운영과정을 모사할 수 있도록 적절한 초기 가중치를 부여하여 모형을 구축하고, 상충되는 목적간의 절충안으로 파레토 프런티어(Pareto-frontier)를 제시할 수 있는 다중목적 의사결정 기법이 요구된다. 본 연구의 목적은 댐 군 연계 운영을 위한 최적화 모형으로 소개된 CoMOM(Coordinated Multi-reservoir Operating Model)의 다중목적함수에 적합한 초기 가중치를 도출할 수 있는 시스템을 제안하는 것이다. 본 연구에서는 최적화 모형에 적합한 가중치를 결정함에 있어 댐의 초기저수량과 미래의 예상 유입량과 같은 수문 조건을 감안할 필요가 있음에 주목하였다. 이것은 초기저수량과 미래에 예상되는 유입량이 작을 경우 가급적 저수에 중점을 두고, 그 반대일 경우는 발전방류에 주안점을 두는 것이 바람직하다는 사실에서 추정해 볼 수 있는 가정이다. 따라서 댐의 초기 저수량 조건과 유입량 시나리오의 다양한 수문 조건별로 가장 적합한 가중치를 찾아본 후, 수문 조건을 입력요소로, 최적 가중치를 출력요소로 갖는 신경망 모형을 활용해서 수문 조건에 적합한 가중치를 예측할 수 있는 절차를 제안한다. 이 과정에서 최적 가중치를 도출하는 것이 관건이 될 수 있는데, 이를 위해 전승목 (2008)등이 제안한 DEA기반 순위결정 절차를 활용해서 최선의 파레토 최적해와 이에 대응되는 가중치를 찾아 이를 신경망 모형의 출력요소 값으로 활용하였다. 본 연구에서 제안하는 신경망 모형은 임의의 수문 상황에 대해 이에 적합한 CoMOM의 초기 가중치를 결정해 줌으로써 CoMOM과 같은 최적화 모형의 가중치 선정에 따르는 어려움을 극복하는 데 도움이 될 수 있을 것으로 기대된다.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.232-237
• /
• 2008

In the Commonwealth of Independent States (CIS), the international organization, or alliance, consisting of eleven former Soviet Republics, their own regulation and standard, codes of the building are based on SNiP issued from the Russia. The SNiP for the seismicity is based on Kazakhstan codes where earthquake is very strong. After their independence, Seismic codes for Former Soviet Republics have been developed in their own accord. The building subjected by more than certain magnitude should be followed by TU as well as SNiP. In this paper, the residential complex project where seismic stability is considered from schematic design will be introduced. In this project, Local analysis program and method for arrangement of bar was applied. In the structural drawings, Korean and Local methods was compromised.

• The Journal of the Korea Contents Association
• /
• v.12 no.9
• /
• pp.202-210
• /
• 2012

Since Civil Law recognizes the freedom of a testament, it recognizes the freedom allowing the decedent to dispose his/her own property at his/her own intention. However, in order to prevent various abuses which may occur when the principle of freedom of testament is carried out unlimited, secured portion system is stipulated. So, absolute freedom of property disposed by the deceased is limited. Likewise, the secured portion system is introduced as the system to resolve the contradiction that exists between principle of freedom of testament and legal inheritance. Since Supreme Court Decision 2010DA50809 delivered on May 24, 2012 includes major legal issues such as how to exercise of claim of return for secured portions, transfer of the secured proportion or the claim of return for secured portions, and exercise of claim of return for secured portions against a third party. So, it has a very important meaning. In this paper, legal issues regarding the exercise of claim of return for secured portions have been reviewed with this decision.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.2C
• /
• pp.217-225
• /
• 2009

Tone injection scheme has been known as one of peak to average power ratio (PAPR) reduction methods deployable to multi-carrier system like orthogonal frequency division multiplexing (OFDM). The basic idea in tone injection scheme is to enforce the constellation size larger so that each of original constellation points is mapped into the preassigned distinct locations. According to the tone injection scheme, it increases symbol power highly induced inherently by expanding constellation to get optimal PAPR reduction. In the other hand, to get optimal power increase, the PAPR would be reduced insufficiently with limited tone injection signal. To withstand these problems, this paper consider the reduction of the PAPR and power increase problem simultaneously, Toward this, the tone injection scheme accomplished by employing the weighted sum genetic algorithm which has been utilized to solve multi-objective optimization problem (MOOP). The simulation results verifies that the proposed scheme can control the effective PAPR performance and alleviation of power increase flexibly by the weight value at the expense of relatively low complexity.

• Journal of Digital Convergence
• /
• v.12 no.5
• /
• pp.125-130
• /
• 2014

The competitiveness in today's global market forces many companies to develop families of products to provide enough variety for the marketplace. The challenge when designing a product family is in resolving the tradeoff between product commonality and distinctiveness. Simultaneously it is necessary to consider environmental performance to design a product family as well as to shorten lead-times, improve quality and reduce costs. This paper proposes a metaheuristic algorithm based redesign methodology for green product family considering environmental performance. The proposed method uses a genetic algorithm as metaheuristic algorithm and green product family index (GPFI) to support green product family design. In addition, it provides the redesign methodology such as product family level and component level. A case study used table lamps as an product family's example shows the verification and effectiveness of the proposed method.

• Journal of Korean Society of Forest Science
• /
• v.89 no.3
• /
• pp.335-341
• /
• 2000

In this study, the multiobjective linear programming (MOLP) formulation was built to solve for the optimal forest management planning considering carbon sequestration and timber production simultaneously. The formulation was applied to a case study problem to investigate the trends of the optimal forest harvest schedules as the function of preference of forest management for carbon sequestration and timber production. The study site was Mt. Kari area in Hongchun. The formulation includes several site-specific constraints for non-declining yields, upper and lower bounds of cut volume and area for timber, ending inventory conditions, etc.. According to the changes of weight combinations for timber production and carbon sequestration, the joint production possibilities curve was proposed as the option for management choice.

• Journal of Korea Water Resources Association
• /
• v.40 no.1 s.174
• /
• pp.1-10
• /
• 2007

Reallocation procedure of multipurpose reservoir storage capacity between flood control and conservation is presented as an alternative to secure more water resources. Storage reallocation is an adaptive management mechanism for converting existing normal pool level of reservoirs to more beneficial uses without requirement for physical alteration. This study is intended to develop a reservoir storage reallocation methodology that allows increased water supply storage without minimizing adverse impacts on flood control. The methodology consists of flood control reservoir simulation for inflows with various return periods, flow routing from reservoir to a potential damage site, analyzing river carrying capacity, and reservoir yields estimation for reallocated storages. For the flood control model, a simulation model called Rigid ROM(Reservoir Operation Method) and HEC-5 are used. The approach is illustrated by applying it to two reservoirs system in Geum River basin. Especially with and without new project conditions are considered to analyze trade-offs between competing objectives.

• Journal of Digital Convergence
• /
• v.19 no.12
• /
• pp.523-530
• /
• 2021

The study is purposed to investigate the current status of assistive technology devices(ATDs) and to explore ways to improve the ATDs support system for work. As a method, domestic and foreign systems were investigated to derive implications can be applied in Korea based on the analysis framework that compromised Gilbert and Terrell's policy analysis model and research purpose. Next, a survey was conducted on 202 disabled supported ATDs for Work. They were looking for a job or working. We would like to suggest a plan as follows. First, it is necessary to improve the support process centered on consumers. Second, the expansion of items and supplementation of the quality management system should be considered. Third, it is urgent to expand the application qualifications. Finally, the foundation for improvement should be continuously laid. We expected the direction of improvement of the support system will be established.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.6
• /
• pp.113-119
• /
• 2018

This paper relates the AM-NM-MMA algorithm which possible to adaptive equalization performance improvement using the adaptive modulus instead of fixed modulus in the NM-MMA algorithm. The NM-MMA emerged for the tradeoff the MMA and SE-MMA algorithm characteristics, the MMA provides the less residual values in the steady state and have a slow convergence rate, the SE-MMA provides the fast convergence rate and increae the risidual values in the steady state. But the fixed modulus can not give the zero residual values in the perfect equalization state and eqaulization performance were degrade, the adaptive modulus was applied in order to reducing the residual values, and its improved performance were confirmed by simulation. For this, the equalizer output constellation, residual isi, MD, MSE, SER were used for performance index. As a result of computer simulation, the AM-NM-MMA has more good performance in equalizer output signal constellation, residual isi, MD, MSE than the NM-MMA, but not in SER performance.