• 한국항만학회지
• /
• 제13권2호
• /
• pp.313-322
• /
• 1999

Pusan the principal port of South Korea, has opened its door since 1876. Currently, the four-stage port construction project is under way to handle ever-growing marine transportation volume. While the port unloading capabilities are increasing the infrastructure to deal with all the transportation volume failed to catch up with them. Accordingly the city had to suffer from worst traffic congestion on due to the increasing container traffic volume causing logistical costs to rise. This study was designed to inspect the enforcement of infrastructure construction plan and suggest systematical and effective ways to improve the plan. The study focused on :\circled1The decision-making procedure, \circled2Financial resource for the plan, \circled3Effectiveness of the project enforcement, and \circled4Who will be in charge of the project. As a result from the study, these followings were suggested to improve the plan. First, Pusan Port Infrastructure consisting of (Inter-city Free way, Belt Highway and Outer Highway) should be immediately legally-regulation project. Second, the method to finance the project should be deter-mined and investment consultation among the central government the city government and private sector should be also made. Measures to make the central government budget allocation for the project mandatory should be discussed. Third, Effectiveness of the project can be doubled by gradually or partialyl opening the routes based on long-term or short-term operating plans. Fourth, The organizer of the project should be appointed, or a special task-force team in charge of the plan can be formed.

• 한국환경보건학회지
• /
• 제40권5호
• /
• pp.425-434
• /
• 2014

Objectives: The purpose of this study is to introduce the establishment process and results of the Seoul Metropolitan Government's road map on environmental health policy. Methods: The process consisted of expert group meetings, civic participation, research, and questionnaire survey for priority environmental health policy agenda items in Seoul. Results: The announced vision for the environmental health policy was "a healthy environment, safety in Seoul". This policy was established in order to define environment health policy initiatives for a period of five years with an aim to protect Seoul citizens' health from hazardous environmental factors. The resulting Seoul environmental health policy consisted of four areas and 16 key agenda items. The four areas were "Protection for children against hazardous materials", "Enhancement of health and safety of all", "Carcinogen-free and endocrine-disrupting chemical-free Seoul (reducing environmental exposure to hazardous materials), and "Establish the foundation of environmental health policy". Sixteen key agenda items include the enhancement of management of spaces for children, certification of environmental health status at schools, establishment of a unit responsible for the environmental health of children, strengthening environmental health management for susceptible populations (children, the aged, and the socioeconomically vulnerable), management of hazardous materials, physical hazardous factors (noise, radiation, etc.), indoor air quality, and the enhancement of monitoring, research, and regulation of environment health. Conclusion: The Seoul Metropolitan Government established an environmental health policy road map for a five-year period (2013-2017). To implement this environmental health policy, budget allocation, and detailed execution plans are required.

• 한국정보통신학회논문지
• /
• 제15권6호
• /
• pp.1289-1300
• /
• 2011

최근 고성능 컴퓨터에서 메모리 사용량이 매우 큰 프로그램과 파일 접근을 많이 하는 프로그램을 동시에 실행하고 있다. 많은 메모리의 사용은 디스크의 스왑 공간에 대해 디스크 접근을 빈번히 발생시키고, 파일 접근은 디스크의 파일 시스템 파티션으로 디스크 접근을 야기한다. 이런 두 종류의 프로그램을 동시에 실행하면 스왑 공간과 파일 시스템 파티션 간에 디스크 탐색이 빈번히 발생할 수 있다. 이런 문제를 해결하기 위해 본 논문은 SAF 기법을 제안한다. 이 기법은 파일 시스템 파티션에 새롭게 여러 개의 스왑 공간을 배치하고, 이들 공간에 페이지-아웃되는 페이지들을 저장한다. 즉, 페이지들은 가장 최근에 접근한 파일의 디스크 위치에 근접한 스왑 공간에 저장된다. 이 스왑 공간이 기존의 스왑 공간에 비해 최근 접근된 파일의 위치로부터 가까운 거리에 있기 때문에 파일 접근 후 발생하는 디스크 탐색의 시간을 크게 줄일 수 있다. 성능 검증을 위해 BSD기반의 FreeBSD 6.2 운영체제에 SAF를 구현하였고, 5개의 벤치마크를 실행하여 성능을 측정하였다. 성능 측정 결과 SAF는 FreeBSD에 비해 벤치마크의 실행 시간을 약 14%∼42% 감소시켰다.

• 벤처혁신연구
• /
• 제3권1호
• /
• pp.165-182
• /
• 2020

본 연구는 간접세인 부가가치세가 지니고 있는 조세부담의 역진성 완화방안과 급격하게 증가하는 사회복지 재원 등 공공재원의 확보 문제를 검토하고, 각 대안에 대한 실질적인 도입 방안을 제시하고자 한다. 부가가치세는 간접세이며, 일반소비세로서 모든 재화와 용역의 공급에 대하여 최종소비자가 조세부담을 함으로서 소득을 세원으로 하는 조세와 비교할 때 경제적 효율성을 지니고 있다. 그러나 조세부담의 역진성으로 인해 공평과세에 있어서는 부적합한 조세라고 보고 있다. 우리나라의 경우 부가가치세율 인상의 경제적 효과는 매우 크기 때문에 부가가치세율의 인상은 쉽지 않다. 그러나 장기적으로는 경제, 사회, 환경 및 에너지, 노령화 등의 문제와 관련하여 부가가치세율의 인상 가능성이 높다고 판단된다. 그러므로 향후 부가가치세율 인상의 논의가 이루어지는 경우 반드시 조세부담의 역진성 문제에 대해 다각도의 정책대안들이 모색되어야만 한다. 이에 본 연구에서는 현행 부가가치세가 가지고 있는 조세부담의 역진성을 파악하고 이를 기초로 정책적 대안들을 제시하고자 하였다. 첫째, 역진성을 완화하기 위해 도입된 면세제도의 적절한 조정과 면세품목 확대와 함께 개별소비세 품목의 조정도 이루어져야 한다. 따라서 둘째, 소득수준 향상과 사회적 배려를 고려하여 면세품목에 대한 조정이 이루어져야할 것이다. 셋째, 실질적인 고소득층의 고가 재화 및 용역의 소비에 대해 세율을 인상 조정함으로써 역진성의 완화를 도모해야 한다. 마지막으로 부가가치세의 특징 중 조세전가의 원리를 심각하게 훼손하고 있는 간이과세제도의 정비가 이루어져야할 것이다.

• 한국컴퓨터정보학회논문지
• /
• 제21권5호
• /
• pp.1-10
• /
• 2016

Magnetic disks have been used for decades in auxiliary storage devices of computer systems. In recent years, the use of NAND flash memory, which is called SSD, is increased as auxiliary storage devices. However, NAND flash memory, unlike traditional magnetic disks, necessarily performs the erase operation before the write operation in order to overwrite data and this leads to degrade the system lifetime and performance of overall NAND flash memory system. Moreover, NAND flash memory has the lower endurance, compared to traditional magnetic disks. To overcome this problem, this paper proposes EPET (Enhanced Prediction and Elapsed Time) wear leveling technique, which is especially efficient to portable devices. EPET wear leveling uses the advantage of PET (Prediction of Elapsed Time) wear leveling and solves long-term system failure time problem. Moreover, EPET wear leveling further improves space efficiency. In our experiments, EPET wear leveling prolonged the first bad time up to 328.9% and prolonged the system lifetime up to 305.9%, compared to other techniques.

• 경영과학
• /
• 제32권1호
• /
• pp.15-33
• /
• 2015

Under complete information, introducing additional constraints to a portfolio will have a negative impact on performance. However, real-life investments inevitably involve use of error-prone estimations, such as expected stock returns. In addition to the reality of incomplete data, investments of most Korean domestic equity funds are regulated externally by the government, as well as internally, resulting in limited maximum investment allocation to single stocks and risk free assets. This paper presents an investment framework, which takes such real-life situations into account, based on a newly developed portfolio selection model considering realistic constraints under incomplete information. Additionally, we examined the effects of additional constraints on portfolio's performance under incomplete information, taking the well-known Samsung and SK group stocks as performance benchmarks during the period beginning from the launch of each commercial fund, 2005 and 2007 respectively, up to 2013. The empirical study shows that an investment model, built under incomplete information with additional constraints, outperformed a model built without any constraints, and benchmarks, in terms of rate of return, standard deviation of returns, and Sharpe ratio.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2005년도 추계학술대회 및 정기총회
• /
• pp.321-333
• /
• 2005

With the limited frequency spectrum and an increasing demand for cellular communication services, the problem of channel assignment becomes increasingly important. However, finding a conflict free channel assignment with the minimum channel span is NP hard. As demand for services has expanded in the cellular segment, sever innovations have been made in order to increase the utilization of bandwidth. The innovations are cellular concept, dynamic channel assignment and hierarchical network design. Hierarchical network design holds the public eye because of increasing demand and quality of service to mobile users. We consider the frequency assignment problem and the base station placement simultaneously. Our model takes the candidate locations emanating from this process and the cost of assigning a frequency, operating and maintaining equipment as an input. In addition, we know the avenue and demand as an assumption. We propose the network about the profit maximization. This study can apply to GSM(Global System for Mobile Communication) which has 70% portion in the world. Hierarchical network design using GA(Genetic Algorithm) is the first three-tier (Macro, Micro, Pico) model, We increase the reality through applying to EMC (Electromagnetic Compatibility Constraints). Computational experiments on 72 problem instances which have 15${\sim}$40 candidate locations demonstrate the computational viability of our procedure. The result of experiments increases the reality and covers more than 90% of the demand.

• 대한물리치료과학회지
• /
• 제16권2호
• /
• pp.45-55
• /
• 2009

Background: This thesis aims at suggesting the direction for the introduction of public free treatment support system according to the establishment of [Special Education Law] and the right settlement of therapeutic support service. Method: It introduced the characteristics and the contents of school based PT & OT, diagnosis and evaluation, and operation method. It set up question items and presented intervention plan, and substantial intervention, beginning from the request of whole process. The diagnostic evaluation was described from 4 aspects, which are consideration matters in the time of document drawing and diagnostic evaluation, chiefly centering around SOAP. The flow of overall treatment support service, the allocation of 16 handicapped children for 1 therapist, and the weekly treatment frequency according to the treatment support location and environment were suggested in the concrete operation method. Result: The concrete method should be explored in order to provide handicapped students with requisite services, which are offered by various experts in the amended 'Special Education Law'. In addition, work condition and social welfare, which are equal to school teachers, should be provided for all experts. Conclusion: Along with these things, special education support center should establish the road-map for the education rehabilitation of the handicapped children from the evaluation of early diagnosis of the handicapped children to treatment support and lifelong education.

• 제어로봇시스템학회논문지
• /
• 제13권7호
• /
• pp.677-682
• /
• 2007

Concurrent competition for finite resources by multiple parts in flexible manufacturing systems(FMS's) and inappropriate initial marking or net structure of Petri net with share resources results in deadlock. This is an important issue to be addressed in the operation of the systems. Deadlock is a system state so that some working processes can never be finished. Deadlock situation is due to a wrong resource allocation policy. In fact, behind a deadlock problem there is a circular wait situation for a set of resources. Deadlock can disable an entire system and make automated operation impossible. Particularly, an unmanned system cannot recover from such a status and a set of jobs waits indefinitely for never-to-be-released resources. In this paper, we proposed a deadlock prevention method using siphon and trap of Petri net. It is based on potential deadlock which are siphon that eventually became empty. This method prevents the deadlock by the control of transition fire and initial marking in the Petri net. An given example of FMS is shown to illustrate our results with deadlock-free.

• 노동경제논집
• /
• 제32권3호
• /
• pp.91-121
• /
• 2009

이 논문에서는 한국의 경우 개별 학군 내에서 사립학교와 공립학교 간에 학생 배분이 무작위로 이루어진다는 특수성을 이용하여, 사립학교가 공립학교에 비해 학생들의 성적향상 측면에서보다 효율적인지를 분석하기 위한 자연실험 분석을 실시하였다. 학군의 고정효과를 통제한 모델을 분석한 결과, 사립학교가 공립학교에 비해 학생들의 성적이 보다 향상된다는 통계적으로 유의미한 결과를 확인할 수 없었다. 단 상위 성적 계층의 여학생들의 경우, 사립학교 학생이 0.13 표준편차만큼 성적이 더 향상되는 것으로 나타났다.