• 제목/요약/키워드: 산학서(算學書)

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A Hybrid Heuristic Approach for Supply Chain Planningwith n Multi-Level Multi-Item Capacitated Lot Sizing Model (자원제약하의 다단계 다품목 공급사슬망 생산계획을 위한 휴리스틱 알고리즘)

  • Shin Hyun-Joon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.1
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    • pp.89-95
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    • 2006
  • Planning distributed manufacturing logistics is one of main issues in supply chain management. This paper proposes a hybrid heuristic approach for the Multi-Level, multi-item Capacitated Lot Sizing Problem (MLCLSP) in supply chain network. MLCLSP corresponds to a mixed integer programming (MIP) problem. With integer variable solutions determined by heuristic search, this MIP problem becomes linear program (LP). By repeatedly solving the relaxed MIP problems with a heuristic search method in a hybrid manner, this proposed approach allocates finite manufacturing resources fur each distributed facilities and generates feasible production plans. Meta heuristic search algorithm is presented to solve the MIP problems. The experimental test evaluates the computational performance under a variety of problem scenarios.

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Selective Dispersion of Carbon Nanotubes by Octadecylainine (옥타데실아민(octadecylamine)을 이용한 탄소나노튜브의 선택적 분산)

  • Lee Kwang-Hoon;Park Hoon;Chae Hee-Baik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.1
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    • pp.27-32
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    • 2006
  • We separated semiconducting single-walled carbon nanotubes(sem-SWCNT) from the HiPco-SWCNTS by dispersion with octadecylamine(ODA). The mixture of acid-treated SWCWTS and ODA was heated at $120^{\circ}C$ for 120hours. ODA physisorbs selectively on the side-wall of sem-SWCNTS. The ODA-treated CNTs were dispersed in tetrahydrofuran(THF) via sonication. The ODA-physisorbed sem-SWCNT can be retained in the supernatant of THF, but met-SWCNT and unabsorbed sem-SWCNT were precipitated in THF. Raman spectra with 514 nm and 1074 nm were investigated. The amount of sem-SWCNT in the supernatant and precipitant was about 94 % and 50 %, respectively.

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Properties of Sol-Gel PZT Thin films with Thickness for Micro Piezoelectric Actuators (마이크로 압전 엑츄에이터용 Sol-Gel PZT 박막의 두께 변화에 따른 특성)

  • 장연태;박준식;김대식;박효덕;최승철
    • Proceedings of the KAIS Fall Conference
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    • 2001.05a
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    • pp.220-223
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    • 2001
  • Pb가 10% 과잉되고 Zr : Ti = 52 : 48 조성을 갖는 PZT sol이 Pt(3500Å)/Ti(400Å)/SiO₂(3000Å)Si(525㎛)기판 위에 스핀 코팅법으로 반복 코팅된 후, 450℃에서 10분, 650℃에서 2분간 반복 열처리되었다. 이와 같이 다양한 두께로 적층된 박막은 각 시편에 대해 최종적으로 650℃ 30분 동안 어닐링 처리되었다. 제조된 PZT 박막의 두께는 4100Å에서 1.75㎛사이의 4종이었다. 이어서 스퍼터링법으로 Pt전극이 PZT 막 위에 증착되었다. 제조된 PZT 박막의 결정 구조 조사를 위해 XRD, 그리고 미세 구조 및 전기적 특성을 알아보기 위해 FESEM과 P-E 이력 곡선이 각각 관찰되었다. 4100Å에서 1.75㎛까지 두께 증가에 따른 장비상의 포화 이력 한계로 잔류 분극(Pr)값이 25μC/㎠에서 다소 감소되었다. 측정된 X선 회절 결과에서 최초 4회 코팅시 perovskite 결정 구조로 성장한 결정립은 (111)배향이 우세하었으나, 두께가 증가됨에 따라 (111)/(110)값이 감소되었으며, 이를 통해 두께 증가에 따른 (111)배향성이 다소 감소됨을 알 수 있었다. 이상의 결과로부터 제조된 PZT 박막은 큰 힘과 높은 내전압 특성을 갖는 마이크로 압전 액츄에이터에 적용될 수 있을 것으로 생각되었다.

The Study on Skin 1st Patch Test of Fermented Hydrolysate from Abalone(Haliotis discus hannai Ino) (발효 전복 추출물의 피부자극에 관한 연구)

  • Lee, Chung-Woo;Hong, Kyung-Hee;Chun, Yong-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.421-424
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    • 2016
  • This study evaluated the efficacy and the skin safety and stability of a cosmetic that is an applied water extract and fermented hydrolysate of abalone (Haliotis discus hannai Ino), which was produced at the south coast of Korea. In the patch test, purified water, 1,3-butylene glycol and liquid crystal lotion were used as the reference group, and water extract and fermented hydrolysate of abalone and lotion formulation of water extract and fermented hydrolysate of abalone were used as the sample group. The results of patch test showed no irritation on skin among in any of the test groups. Therefore, the water extract and fermented hydrolysate of abalone (Haliotis discus hannai Ino) are safe for human skin.

Optimum design and performance of marine sea water pump with impeller using CFRP (CFRP 임펠러를 사용한 선박용 해수펌프의 최적설계와 성능특성)

  • Jeong, Seon Yong;Rhi, Seok Ho;Seo, Hyoung Seock;Lee, Kye Bock
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7878-7884
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    • 2015
  • Marine sea water pump with impeller using carbon fiber block was developed to prevent the impeller corrosion by the salinity. A numerical analysis was carried out in order to optimize the impeller and volute design for marine sea water pump and to investigate the sensitivity of the related parameters(impeller thickness, surface roughness) using CFD commercial code. The impeller thickness is limited because of the weight. Since the impeller using the carbon fiber lights, the thickness which has a maximum efficiency can be used. The results show that the surface roughness leads to an 7% reduction in pump efficiency.

A Study on Characteristics of column fails in DDI DRAM (DDI DRAM에서의 Column 불량 특성에 관한 연구)

  • Chang, Sung-Keun;Kim, Youn-Jang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1581-1584
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    • 2008
  • In dual-polycide-gate structure with butting contact, net doping concentration of polysilicon was decreased due to overlap between $n^+$ and $p^+$ and lateral dopant diffusion in silicide/polysilicon layers. The generation of parasitic Schottky diode in butting contact region is attributed both to the $CoSi_2$-loss due to $CoSi_2$ agglomeration and to the decrease in net doping concentration of polysilicon layer. Parasitic Schottky diode reduces noise margin of sense amplifier in DDI DRAM, which causes column fail. The column fail could be reduced by physical isolation of $n^+/p^+$ polysilicon junction or suppressing $CoSi_2$ agglomeration by using nitrogen implantation into $p^+$ polysilicon before $CoSi_2$ formation.

A study on the intelligent USN middleware platform based on the group concept (그룹 개념 기반 지능형 USN 미들웨어 플랫폼 연구)

  • Lee, Chang-Yeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1666-1672
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    • 2008
  • USN Middleware plays roles of broker between sensors and applications. It collects sensor data, decides the situation and sends the result to the applications. It is not good to decide the situation from one sensor data, because it may error data or reflect small part of all. In this paper, we propose sensor 'group' concept. Group is the primary unit to decide the situation. It consists of several sensors which were installed in the same place and had the same pre-defined condition to act. For example, all fire sensors in the room simultaneously trigger the ring when the same pre-defined temperature is recorded. Then, the all fire sensors are included to the same one sensor group. All operations of the intelligent USN middleware are based on the 'group' unit. We studied the intelligent rules of USN middleware based on the group.

A Method of Conclusion of Traffic Control Signal Proposal using Fuzzy Analytic Hierachy Process (퍼지AHP를 이용한 교통신호제어기의 교통대안확정방법)

  • Jin, Hyun-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1592-1598
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    • 2008
  • Fixed cycle traffic signal controller is pattern type controller. This method is that one concluding traffic proposal affect fixed cycle controller to deciding cycle time during 24 hours. Traffic intersection jam is caused traffic controller supervisor input wrong traffic proposal. The available to traffic controller is traffic proposal is not selected by an outward look but propriety traffic proposal is compared with each other. This paper presents that property traffic proposal adopted to fixed cycle controller by fuzzy analytic hierachy process and new proposal adopted fixed cycle controller is compared with others.

A Study on Tertiarization in Korea: Test of Baumol's Hypothesis (한국의 서비스화에 대한 연구: Baumol 가설을 중심으로)

  • Seo, Hwan-Joo;Lee, Young-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.143-150
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    • 2007
  • Using a panel data of Korea for $1979{\sim}2002$, this study investigates the determinants of the service sector employment share in Korea. In order to analyze the impact of macroeconomic factors on the service sector's employment share we estimate a simple panel model which is in line with Baumol's model. The panel GMM estimation results show that: 1) The increase in the share of service-related jobs in total employment tends to rise with GDP per capita, which confirms demand-bias hypothesis proposed by Clark. 2) We find that a crucial role in this process has been played by the productivity gap. As Baumol's hypothesis or Baumolis disease, the expansion of the employment share in services relative to industry is the direct consequence of services' lower productivity performances.

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Diagnostic Classification Based on Nonlinear Representation and Filtering of Process Measurement Data (공정측정데이터의 비선형표현과 전처리를 활용한 분류기반 진단)

  • Cho, Hyun-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3000-3005
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    • 2015
  • Reliable monitoring and diagnosis of industrial processes is quite important for in terms of quality and safety. The goal of fault diagnosis is to find process variables responsible for causing specific abnormalities of the process. This work presents a classification-based diagnostic scheme based on nonlinear representation of process data. The use of a nonlinear kernel technique is able to reduce the size of the data considered and provides efficient and reliable representation of the measurement data. As a filtering stage a preprocessing is performed to eliminate unwanted parts of the data with enhanced performance. The case study of an industrial batch process has shown that the performance of the scheme outperformed other methods. In addition, the use of a nonlinear representation technique and filtering improved the diagnosis performance in the case study.