• 제목/요약/키워드: Reduction Feasibility Check

검색결과 12건 처리시간 0.027초

불규칙형상 박판제품의 블랭킹 및 피어싱용 CAD/CAM 시스템 (A CAD/CAM System for Blanking or Piercing of Irregular Shaped-Sheet Metal Products)

  • 최재찬;김철;박상봉
    • 한국정밀공학회지
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    • 제15권8호
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    • pp.174-182
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    • 1998
  • This paper describes a research work of developing a computer-aided design and machining of irregular shaped-sheet metal product for blanking or piercing operation. An approach to the CAD/CAM system is based on the knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data conversion, modelling, and post-processor module. Based on knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product, complexities of blank geometry and punch profile, diameter and material of a wire, and availability of press. This system is capable of generating NC data automatically according to drawings of die-layout module. Results which are carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing die in this field.

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제어냉각 장치를 이용한 엔진피스톤 열간단조 공정에 관한 연구 (Hot Forging of an Engine Piston using Control Cooling)

  • 이상익;최동환;이정환
    • 소성∙가공
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    • 제24권6호
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    • pp.411-417
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    • 2015
  • The piston engine is an essential component in automobiles. Since the piston is used in a high temperature and high pressure environment, the piston needs to be manufactured to achieve high strength and high durability. In addition, cost reduction is also an important consideration. In conventional forging, an additional heat treatment after hot forging is necessary to ensure proper mechanical properties for heavy-duty engine pistons. The newly developed manufacturing method lowers production costs by saving manufacturing time and reduces energy consumption. The current paper describes the hot forging of an engine piston made from 38MnSiVS5 micro-alloyed steel using controlled cooling. The finite element analysis was used to check for possible problems and suitable press capacity. Hot forging experiments were then conducted on a 2500tons crank press to evaluate feasibility of the proposed material and process. To check the mechanical properties after hot forging, the forged specimens were tensile tested, and the microstructures were examined in order to compare the results with the conventionally forged material. The skirt region of the as-forged 38MnSiVS5 piston showed better material properties compared to the conventional material. In addition, the total production time was reduced by about 80% as compared to conventional forging.

산성비 원인물질인 이산화황 저감모형 구축과 평가에 관한 연구: Global 2100 모형을 중심으로 (Development and Evaluation on a Model for Reducing SO2: Case Study on Global 2100 Model)

  • 이동근
    • 환경영향평가
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    • 제6권2호
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    • pp.93-102
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    • 1997
  • Acid rain below pH 5.6 is responsible for 40% of annual precipitation in Korea and it is more serious especially in major cites. Because of that, it is urgent to make measures to reduce the emission of $SO_2$, one of the major air pollutants causing acid rain. The national total emission of $SO_2$ in 1994 was estimated as 1.6 million tons. The $SO_2$ emission in 2020, is expected to increase up to 3.2 million tons, about 2 times that of 1994 under Business-As-Usual scenario. We could take various $SO_2$ reduction measures such as installing desulfurization facilities, the supply of low-sulfur oil and clean fuel(LNG), energy savings, upgrading of production process. However, it is necessary to check the economic feasibility and the attainability to reduction target with a dynamic optimization mode, "Global 2100 Model". The cost-benefit analyses for the measures using the revised "Global 2100 Model" clearly revealed that the desulfurization facilities should be introduced to reduce the $SO_2$ concentration to 0.01 ppm with fuel substitution. If the introduction of desulfurization facilities is delayed, We can not attain the goal of Ministry of Environment before the year of 2012, even in the case that almost all the fuels would be substituted with LNG.

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에너지 절감을 위한 태양광 발전시스템의 선박 적용 타당성 연구 (A Study on the Feasibility of Applying Solar Power Generation Systems to Merchant Ships for Energy Saving)

  • 김경환;전현민;김성완
    • 해양환경안전학회지
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    • 제27권7호
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    • pp.1067-1073
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    • 2021
  • 선박으로부터 발생하는 온실가스 배출을 저감하기 위한 규제가 점차 강화되고 있다. 현존선에서도 EEXI(Energy Efficiency Existing Index)가 도입되었으며 이와 같은 온실가스 배출 감축목표를 달성하기 위해 다양한 연구가 진행되고 있다. 본 연구에서는 국제항해에 종사하는 현존선 중 자동차운반선에 태양광 발전시스템을 적용하여 연료유 사용량을 줄임으로써 온실가스 배출이 저감될 수 있는 시스템을 제안하였다. 제안된 태양광 발전시스템은 태양광 모듈, 에너지저장시스템, 전력변환장치 등으로 구성되었으며, 본 시스템의 적용 가능성을 확인하기 위해 전력전자프로그램을 통해 시스템을 모델링하였으며, 시뮬레이션을 실시하였다. 또한, 실제 선박에 적용하기 위한 타당성 검증을 위해 경제성 분석을 실시하였으며, 약 11년 이후 경제성 부분에서도 유의미한 결과가 도출됨을 확인할 수 있었다.

영상 디코더의 제한된 버퍼를 고려한 전력 최소화 DVFS 방식 (Power-Minimizing DVFS Algorithm for a Video Decoder with Buffer Constraints)

  • 정승호;안희준
    • 한국통신학회논문지
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    • 제36권9B호
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    • pp.1082-1091
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    • 2011
  • DVFS (Dynamic Voltage and Frequency Scaling) 에 기초한 저전력 기법은 배터리를 사용하는 모바일 장치에서 동작시간 향상을 위하여 매우 중요하다. 본 연구에서는 DVFS기법에 기반을 둔 영상디코더의 에너지 소비를 최소화핸 스케줄링 알고리즘을 제안 한다 특히, 기존연구에서 간과된 디코더와 디스플레이 사이에 위치한 버퍼의 크기 제약을 모델에 포함하여 버퍼 넘침을 방지 하도록하며, 이 모델에서 수학적으로 에너지를 최소화하는 알고리즘을 제안하고 증명하였다. 실제 영상을 통한 시뮬레이션 결과 버퍼의 크기가 10 프레임정도에서 이득이 포화상태가 되며, 제안된 알고리즘이 기존의 직관적인 알고리즘들에 비하여 평균 10% 정도의 전력소모 절약을 얻을 수 있음을 확인하였다.

전산 열해석 DB를 이용한 초고온 진공로 최적설계 (Optimal Design of High Temperature Vacuum Furnace Using Thermal Analysis Database)

  • 리진철;박미영;변영환;이창진;이재우
    • 대한기계학회논문집B
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    • 제30권6호
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    • pp.594-601
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    • 2006
  • Optimization study has been carried out to design an energy efficient, high temperature vacuum furnace which satisfies users' design requirements. First of all, the transient temperature distribution and the uniform temperature zone results have been compared with the steady state results to validate the feasibility of using steady state solution when constructing the thermal analysis DB. In order to check the accuracy, the interpolated results using thermal analysis DB have been compared with the computational and the experimental results. In this study, total heat flux is selected as the objective function, and the geometry parameters of vacuum furnace including the thickness of insulator, the heat zone sizes and the interval between heater and insulator are the design variables. The Uniform temperature zone sizes and the wall temperature are imposed as the design constraints. With negligible computational cost a high temperature vacuum furnace which has $40\sim60%$ reduction in total heat flux is designed using thermal analysis DB.

0.5 MWth 급 케미컬루핑 연소시스템에서 대량생산 입자의 고체순환 특성 및 반응 특성 (Solid Circulation and Reaction Characteristics of Mass Produced Particle in a 0.5 MWth Chemical Looping Combustion System)

  • 류호정;조성호;이승용;이도연;남형석;황병욱;김하나;김정환;백점인
    • 한국수소및신에너지학회논문집
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    • 제30권2호
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    • pp.170-177
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    • 2019
  • Continuous solid circulation test at high temperature and high pressure conditions and batch type reduction-oxidation tests were performed to check feasibility of a 0.5 MWth chemical looping combustion system. Pressure drop profiles were maintained stable during continuous solid circulation up to 16 hours. Therefore, we could conclude that the solid circulation between an air reactor and a fuel reactor could be smooth and stable. The measured fuel conversion and $CO_2$ selectivity were high enough even at high capacity and even after cyclic tests. Therefore, we could expect high reactivity of oxygen carrier at real operation condition.

식재료 아웃소싱이 경제적 주방에 미치는 영향에 관한 연구 - 특1급호텔 양식조리를 중심으로 - (Study on economic effects of outsourcing of food materials on the hotel kitchen - Focus on cooking Western food in the first class hotel -)

  • 성태종
    • 한국관광식음료학회지:관광식음료경영연구
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    • 제13권2호
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    • pp.45-69
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    • 2002
  • This study is designed to examine feasibility and limitation of outsourcing in cooking Western food in a hotel, to interpret importance of outsourcing(eg. outside order, outside procurement, outside supply) in a broad sense in order to reinforce the core capacity in the cooking department, and to know whether the cooking human power is efficiently used and how much the chefs recognize outsourcing of food materials. As many companies conduct restructuring to cut down its size, the reduction of human power led the Western food cooking in the hotel to lower core capacities, lower quality, and lower efficiency. In addition, the sagging morale of chefs undermined creativity. To change from the traditional kitchen to an economic kitchen needs to look into importance of outsourcing, cognitive attitude of chefs, relation with outside suppliers. Here suggests performance of positive changes in the structure The study examined feasibility and limitation of outsourcing in the hotel kitchen as well as chefs' cognitive attitude toward outsourcing of food materials to reinforce core capabilities of the hotel kitchen. 1. Companies of outsourcing are selected according to variability of price conditions, flexibility of contract conditions, popularity of the outsourcing company, and reputation of the outsourcing company. 2. The importance of outsourcing in the Western food cooking is divided into 4 factors such as standard of selecting outsourcing companies, policies of cooking manu, quality of cooking, and quantity of cooking. 3. The most feasible section in outsourcing of food materials is a process of kneading flour for bread, which shows that many Western-food chefs expect to put higher possibility of outsourcing on the kneading. In other words, when it comes to confectionery and bakery, there are many outside expert processing companies supplying high quality products. In the order of outsourcing feasibility, sauce is followed by processed vegetable, garnish of main dish, and soup. The least feasible section in outsourcing of food materials is appetize. Appetize includes a concept of a improvised dish and needs speed. Due to its color, freshness, and sensibility of taste, the appetize plays a key role in the Western food cooking. 4. When outsourcing is taken in place, the highest risk is to lower the inner cooking skills. Therefore chefs in charge of the Western food sequently recognize both internal problems including storage of cooking skills, unstability of layoffs, and loss of cooperation between departments, and external problems including inferior goods, difficulty of differentiating manu, delay of delivery, and expiration date. It shows that most of the Western food chefs consider risks of the internal problems at first. 5. A effective outsourcing needs appropriate selection of outsourcing companies, maintenance of credibility, active communication, check and management of hygiene. However regardless of their position or career, chefs in charge of the Western food have the same cognitive attitude toward selecting successful outsourcing companies after the outsourcing system is enforced. The core of cooking, or a final stage in the full process of so-called artistic cooking, should be treated with insourcing. Reduction of several cooking processes resulted in shortened cooking time, increased efficiency, faster cooking, cutting the waiting-lines, and finally more room for customers. The outsourcing system can reduce or eliminate the following processes in cooking: buying various food materials, checking, storing, preparing, and processing. Especially in the Western food cooking department of a hotel, the outsourcing system should be enforced to make an economic kitchen and to efficiently manage it. Wow it's time to change from the traditional kitchen to an economic kitchen in the hotel cooking department. For that, the cooking department should become a small but strong organization by outsourcing except its core work.

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사례분석을 통한 농촌형 저탄소 녹색마을 타당성 검토 (A Study on the Validity of Rural Type Low Carbon Green Village Through Case Analysis)

  • 도인환;황은진;홍수열;배재근
    • 대한환경공학회지
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    • 제33권12호
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    • pp.913-921
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    • 2011
  • 본 연구는 저탄소 녹색마을을 Y군의 협조를 얻어 A, B, C마을에 설치한다는 전제에서 환경성, 경제성, 에너지자립도 등을 분석하여 종합적인 타당성을 검토하였다. 대상 바이오매스의 종류 및 양은 가축분뇨 28톤/일, 과수전정지 2톤/일로 하루 30톤 규모로 시설용량을 설정, 시설은 습식계(가축분뇨) 바이오매스를 이용한 바이오가스화 시설과 건식계(전정가지) 바이오매스를 이용한 화목보일러 시설, 열병합발전기, 퇴비화시설 등으로 구성하였다. 구성된 시스템을 운전하였을 때, 전기생산량은 540,540 kWh/년, 열에너지 생산량은 1,762 Gcal/년으로 분석되었다. 대상마을 가구(129가구)에서 기존에 사용하고 있는 전기에너지는 309,600 kWh/년으로 시설에서 생산된 전기에너지를 공급하면 대상지역의 전기에너지 자립률은 100%가 되며, 잉여전력은 230,940 kWh/년이었다. 또한 열에너지는 대상마을의 비닐하우스에서 소요되는 양을 산정하였으며, 기존 사용량 1,415 Gcal/년으로 열에너지 자립률 역시 100%가 되며, 잉여량은 347 Gcal/년이 되었다. 경제성은 시설설치비용 504,000만원, 운영비 48,509만원, 수익 33,712만원으로 연간 약 1억 4천만원 적자, 15년 동안 약 22억원의 적자이나, 환경성 분석에서 원유대체효과 약 178백만원, 온실가스감축효과 약 92백만원으로 연간 총 2억 7천만원의 환경적 편익이 발생되어, 종합적으로는 연간 약 1억 3천만원 정도의 편익이 발생되었다. 정부 및 지자체의 예산지원을 통하여 진행되더라도 경제성, 환경성, 에너지자립도를 종합하여 볼 때, 충분한 타당성이 있는 사업이라고 판단되었다.

신호위반 단속시스템 설치에 따른 교통사고 감소 효과와 편익산정 기법 연구 (Analysis of the Crash Reduction Effects of the Red Light Camera Systems and Determination of the User Benefits)

  • 김상엽;최재성;김명규;성현진
    • 한국ITS학회 논문지
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    • 제10권1호
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    • pp.1-15
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    • 2011
  • 신호위반 단속시스템은 신호교차로에서 운전자들이 신호를 위반해서 통과하는 것을 방지하기 위해 설치하는 지능 형교통체계 사업의 한 형태로서 지난 십여년간 우리나라에서 큰 호응을 얻어 설치되는 중이다. 그 동안 사람들은 대개 신호위반 단속시스템을 설치하면 당연히 운전자 안전이 제고될 것으로 받아들였기 때문에 신호위반 단속시스템을 설치하는데 문제가 없었다. 그러나 향후 신호위반 단속시스템을 설치할 때 보다 효율성을 더 높이고 일반인들로부터 보다 큰 호응을 끌어내기 위해서는 신호위반 단속시스템 설치 효과를 좀 더 정확히 분석할 수 있는 방법이 요구된다. 이 요구를 만족시키기 위해, 이 연구는 다음과 같은 연구를 수행했다. 첫째, 신호위반 단속시스템의 효과를 밝히기 위해 신호위반 단속시스템 설치 이후 나타난 운전자들의 신호위반 건수를 분석했다. 둘째, 신호위반 단속시스템 설치 이후 나타난 교통사고 발생건수를 수집해서 신호위반 건수와 비교했다. 셋째, 신호위반 건수와 교통사고 발생건수 간 관계식을 규명하기 위해 음이항분포를 적용한 통계분석을 수행했으며, 교통사고 건수는 신호위반 단속시스템 설치여부, 교통량, 차량속도, 신호현시 수, 주도로 직진 차로 수와 밀접한 관계가 있는 것으로 밝혀졌다. 끝으로, 이 연구에서 산출한 분석결과를 토대로 하여 신호위반 단속시스템 설치 이후 나타나는 안전성 효과를 분석할 수 있는 기법을 제시했는데, 이 기법은 신호위반 단속시스템이 나타낼 경제적 효과를 분석하는데 기여할 것이다.