• Title/Summary/Keyword: Reduction Feasibility Check

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

  • 최재찬;김철;박상봉
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.8
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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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Hot Forging of an Engine Piston using Control Cooling (제어냉각 장치를 이용한 엔진피스톤 열간단조 공정에 관한 연구)

  • Lee, S. I.;Choi, D. H.;Lee, J. H.
    • Transactions of Materials Processing
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    • v.24 no.6
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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.

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

  • Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.6 no.2
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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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A Study on the Feasibility of Applying Solar Power Generation Systems to Merchant Ships for Energy Saving (에너지 절감을 위한 태양광 발전시스템의 선박 적용 타당성 연구)

  • Kim, Kyunghwan;Jeon, Hyeonmin;Kim, Seongwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.7
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    • pp.1067-1073
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    • 2021
  • Regulations to reduce greenhouse gas emissions from ships are gradually being strengthened. EEXI (Energy Efficiency Existing Index) has been introduced in existing ships, and various studies are aimed at achieving the greenhouse gas emission reduction target are currently underway. In this study, we proposed a method to reduce greenhouse gas emissions through reducing fuel oil consumption by applying a solar power generation system to a pure and truck carrier among existing ships engaged in international voyages. The proposed photovoltaic power generation system consists of a photovoltaic module, an energy storage system, and a power conversion device. To confirm applicability, the system was modeled through a power electronics program, and a simulation was performed. In addition, economic analysis was conducted to check the feasibility of application to real ships, and it was confirmed that significant results were derived in the economical aspect after about 11 years had elapsed.

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

  • Jeong, Seung-Ho;Ahn, Hee-June
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.9B
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    • pp.1082-1091
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    • 2011
  • Power-reduction techniques based on DVFS(Dynamic Voltage and Frequency Scaling) are crucial for lengthening operating times of battery powered mobile systems. This paper proposes an optimal DVFS scheduling algorithm for decoders with memory size limitation on display buffer, which is realistic constraints not properly touched in the previous works. Furthermore, we mathematically prove that the proposed algorithm is optimal in the limited display buffer and limited clock frequency model, and also can be used for feasibility check. Simulation results show the proposed algorithm outperformed the previous heuristic algorithms by 7% in average, and the performance of all algorithms using display buffers saturates at about 10 frame size.

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

  • Li Zhen-Zhe;Park Mee-Young;Byun Yung-Hwan;Lee Chang-Jin;Lee Jae-Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.6 s.249
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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.

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

  • RYU, HO-JUNG;JO, SUNG-HO;LEE, SEUNG-YONG;LEE, DOYEON;NAM, HYUNGSEOK;HWANG, BYUNG WOOK;KIM, HANA;KIM, JUNGHWAN;BAEK, JEOM-IN
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.2
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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.

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

  • 성태종
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.13 no.2
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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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A Study on the Validity of Rural Type Low Carbon Green Village Through Case Analysis (사례분석을 통한 농촌형 저탄소 녹색마을 타당성 검토)

  • Do, In-Hwan;Hwang, Eun-Jin;Hong, Soo-Youl;Phae, Chae-Gun
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.12
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    • pp.913-921
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    • 2011
  • This study examined the overall feasibility of low carbon green village formed in rural area. The check method is analyzing its environmental and economic feasibility and energy self-reliance. The biomass of the villages was set as 28 ton/day of livestock feces and 2 ton/day of cut fruit tree branches which make up the total of 30 ton/day. The facility consisted of a bio gasfication facility using wet (livestock feces) biomass and combined heat power generator, composting facility and wood boiler using dry (cut fruit tree branches) biomass. When operating the system, 540,540 kWh/yr of electricity and 1,762 Gcal/yr of heat energy was produced. The region's electricity energy and heat energy self-reliance rate will be 100%. The economic feasibility was found as a loss of 140 million won where the facility installation cost is 5.04 billion won, operation cost is 485.09 million won and profit is 337.12 million won. There will be a loss of about 2.2 billion won in 15 years but in the environmental analysis, it was found that crude replacement effect is about 178 million won, greenhouse gas reduction effect is about 92 million won making up the total environmental benefit of 270 million won. This means, there will be a yearly profit of about 130 million won. In terms of its environmental and economic feasibility and energy self-reliance, this project seemed to be a feasible project in overall even if it manages to get help from the government or local government.

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

  • Kim, Sang-Youp;Choi, Jai-Sung;Kim, Myung-Kyu;Sung, Hyun-Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.1
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    • pp.1-15
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    • 2011
  • The RLC systems is one of the intelligent transportation systems that has gained a nation-wide support for last decades and being installed to discourage motorists from running the red lights at signalized intersections. It is taken for granted that the RLC will provide motorists with increased safety, so that their installments are always justifiable. However, in order to acquire more efficiency and wider supports from the general public in future RLC installments, an improved methodology for analyzing the effects of the RLC systems is required. In order to satisfy this requirement, this research performed the following tasks. First, the number of signal violations after the RLC systems were investigated in order to check its resulting effects. Second, the number of crashes after the RLC systems were collected and compared with the number of signal violations. Third, a statistical analysis was carried out to develop the relationships between the signal violations and the crashes based on negative binomial distribution. The analysis revealed that the number of crashes has a close relationship with the RLC placement, traffic volume, vehicle speed, the number of phases, and the number of lanes for major approaches. Finally, based on the results found in this analysis, this research presents a methodology for analyzing the safety effects of placing the RLC that should be of service when investigating the economic consequences of the RLC systems.