• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.114-117
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• 2009

In this work, closing behavior of the voids generated in a casting process was investigated for various parameters such as reductions in height void size and billet rotation during hot open die forging process. The reduction in height and path schedule including the number of paths and billet rotation were chosen as key process variables to express the change of geometrical void shape and void closing behavior. On the other hand, values of die overlapping and die width ratio were set to be constant. Extend of void closure was observed and evaluated using tensile test and microscope. Based on the experimental result, it is ensured that void closure do not occur at 15% and 30% reduction in height as well as one or two rotations of a billet. The useful datum obtained from this study could be utilized to establish an optimum path schedule in the open die forging process.

• 산업경영시스템학회지
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• 제38권3호
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• pp.78-86
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• 2015

Up-to-date business environment for manufacturers is very complex and rapidly changing. In other words, companies are facing a variety of changes, such as diversifying customer requirements, shortening product life cycles, and switching to small quantity batch production. In this situation, the companies are introducing the concept of JIT (just-in-time) to solve the problem of on-time production and on-time delivery for survival. Though many companies have introduced ERP (enterprise resource planning) systems and MRP (material requirement planning) systems, the performance of these systems seems to fall short of expectations. In this paper, the case study on introducing an APS (advanced planning and scheduling) system based on dispatching rules to a machining company and on finding a method to establish an efficient production schedule is presented. The case company has trouble creating an effective production plan and schedule, even though it is equipped with an MRP-based ERP system. The APS system is applied to CNC (computer numerical control) machines, which are key machines of the case company. The overall progress of this research is as follows. First, we collect and analyze the master data on individual products and processes of the case company in order to build a production scheduling model. Second, we perform a pre-allocation simulation based on dispatching rules in order to calculate the priority of each order. Third, we perform a set of production simulations applying the priority value in order to evaluate production lead time and tardiness of pre-defined dispatching rules. Finally, we select the optimal dispatching rule suitable for work situation of the case company. As a result, an improved production schedule leads to an increase in production and reduced production lead time.

• 보건행정학회지
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• 제7권2호
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• pp.65-88
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• 1997

In Korea, telemedicine is still under the beginning stage, but we expect that the developing 'Information Highway' will make this technology more common place and more easily used in coming soon. Currently, three hospitals are providing telemedicine services with their subsidiary hospitals which are far away from their remote place. However, the fee schedule of telemedicine services are not well-settled down, of course not reimbursed through current health insurance system. This study aims to develop new payment system for medical services provided through telemedicaine system. To design appropriate fee schedule for telemedicine services, we, first, review the current insurance payment system and telemedicine system both in domestic and foreign countries focusing on its payment system. A framework of telemedicine payment system is proposed in following steps based on information we acquired from this stage. Second. We decide the span of cost items which should be covered by telemedicine payment scheme. In hear, we suggest payment method for telemedicine services should be designed as dual structure which are telemedicine fee that should be reimbursed through payment scheme and any costs related to capital investment that should not be covered by payment system. Which is, payment system for telemedicine services should cover only service-related costs and any costs related to capital investment should be generated through third party such as government, health insurance association, etc. Finally, we suggest new fee schedules for telemedicine services. The key issues on developing telemedicine fee schedules are related with the determination of appropriate additional rate($\alpha$). The reasonable additional rate($\alpha$) must determine through careful evaluation of any additional efforts(e. g. : additional work hours which are related to providing telemedicine services). This study shows the process of how to determine appropriate additional rate($\alpha$).

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.286-289
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• 2003

턴키공사는 설계를 도급자가 하기 때문에 설계오류로 인한 공사금액의 증액은 없다. 따라서 설계오류로 인한 공사비의 증가는 도급자의 원가율을 상승시키는 결과를 초래하고 그로인한 도급자의 채산성은 감소할 수 밖에 없는 실정이다. 또한 설계오류는 설계변경의 기간만큼 공정을 지연시키고 오류를 인식하지 못하는 경우 심각한 품질문제를 야기 시킬 수 있다. 본 연구에서는 턴키공사의 설계오류 원인을 조사하여 설계오류를 감소시킬 수 있는 방안을 제시함으로써 설계오류로 인한 원가율 상승과 공정지연, 품질저하의 문제점을 해소하고자 한다.

• 기록학연구
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• 제55호
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• pp.5-38
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• 2018

공공기관에 대한 신뢰는 책임성(accountability)과 밀접하게 관련된다. 공공기관의 책임성을 높이는 핵심 전략은 주요 업무와 정책의 과정과 결과를 기록증거로 충분히 남기는 것이다. 이는 곧 '공공업무의 철저한 기록화'라고 볼 수 있는데, 이를 위하여 가장 중심이 되는 기록관리업무는 기록평가다. 이 연구의 목적은 공공기관의 책임성 강화를 위한 기록평가정책의 재설계 방향을 제시하는 것이다. ISO 15489-1:2016에서 새롭게 도입된 평가의 개념에 입각하여 책임성과 평가의 관계를 정리하였고, 책임성 관점에서 기록관리평가제도의 문제점을 분석하였다. 이러한 분석을 토대로 기록평가정책의 재설계 원칙과 평가를 위한 핵심 도구로서 기록관리기준표의 전면 재설계, 기록처분동결제도의 도입을 제안하였다.

• 한국정보통신학회논문지
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• 제20권4호
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• pp.786-792
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• 2016

Camellia 암호는 NTT사 및 미쓰비시 전자회사에서 공동으로 2000년도에 개발되었다. Camellia는 128비트 메시지 블록 크기와 128비트, 192비트 및 256비트 키(Key)에 대한 암호화 방식을 규정하고 있다. 본 논문은 키 스케줄용 레지스터 설정과 기존의 라운드 연산 블록을 통합한 수정된 라운드 연산 블록을 제안하였다. 키 생성과 라운드 연산에 필요한 총 16개의 ROM을 단지 4개의 이중포트 ROM만을 사용하여 구현하였다. 또한 메시지 버퍼를 제공하여 키 생성을 위한 KA와 KB 값이 도출되면 대기 시간없이 즉시 암호화나 복호화가 수행될 수 있도록 하였다. 제안한 Camellia 블록 암호 알고리즘을 Verilgo-HDL을 사용하고 설계하고, Virtex4 디바이스상에 구현하였으며, 최대 동작 주파수는 184.898MHz이다. 128비트 키 모드에서 최대 처리율은 1.183Gbps이며, 192비트 및 256비트 키 모드에서 최대 처리율은 876.5Mbps이다. 본 논문에서 설계된 암호 프로세서는 스마트 카드, 인터넷뱅킹, 전자상거래 및 위성 방송 등과 같은 분야의 보안 모듈로 응용이 가능할 것으로 사료된다.

• 스마트미디어저널
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• 제4권4호
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• pp.39-46
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• 2015

본 논문은 사물인터넷 보안용 경량 암호 알고리듬 중, '128비트 블록 암호 LEA'의 암호화 블록 하드웨어 구현에 대해 기술한다. 라운드 함수 블록과 키 스케줄 블록은 높은 처리성능을 위하여 병렬회로로 설계되었다. 암호화 블록은 128비트의 비밀키를 지원하며, FSM 방식과 24/n단계(n = 1, 2, 3, 4, 8, 12) 파이프라인 방식으로 설계되었다. LEA-128 암호화 블록을 Verilog-HDL로 모델링하여 FPGA 상에서 구현하고, 합성결과로부터 최소면적 및 최대처리성능을 제시한다.

• The Journal of the Acoustical Society of Korea
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• 제21권4E호
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• pp.170-177
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• 2002

The goal of the present research is to improve a quality of life of the elderly with a dementia. In this paper, it is realized by developing the dialog system that is controlled by three kinds of modules such as speech recognition engine, graphical agent, or database classified by a nursing schedule. The system was evaluated in an actual environment of a nursing facility by introducing it to an older male patient with dementia. The comparison study between dialog system and professional caregivers was then carried out at nursing home for 5 days in each case. The evaluation results showed that the dialog system was more responsive in catering to needs of dementia patient than professional caregivers. Moreover, the proposed system led the patient to talk more than caregivers did.

• 소성∙가공
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• 제19권8호
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• pp.480-485
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• 2010

In this work, the closing behavior of cylindrical-shaped voids was experimentally investigated according to various parameters such as reduction ratio in height, initial void size and billet rotation during hot open die forging process. The reduction ratio in height, number of path, and billet rotation were chosen as key process parameters which influence the void closing behavior including the change of void shape and size. On the other hand, values of die overlapping and die width ratio were set to be constant. Void closing behavior was estimated by microscopic observation. Based on the observations, it was confirmed that application of billet rotation is more efficient to eliminate the void with less reduction ratio in height. The experimental results obtained from this study could be helpful to establish the optimum path schedule of open die forging process.

• 기술사
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• 제33권4호
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• pp.44-47
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• 2000

Recently number of reinstrumentation projects in the process plants has grown to meet the needs to modernize or upgrade the exsisting control systems in a bid to boost productivity and quality. Design, installation and start-up of these process automation systems can be successful and trouble-free only if decision points are addressed properly. The critical decision points are encountered from tile design through the start-up phases of implementing a modernization project and discussed extensively here on a practical basis. Key points are ;to assign a project manager out of the plant instrument engineers for him to organize and lead a project team. ;to follow three critical steps in designing and implementing. :to think ahead of the critical steps and to induce a positive cooperation from all level of participants in the effort to prevent possible schedule delays.