• Title/Summary/Keyword: Investigation Practice

Search Result 576, Processing Time 0.027 seconds

Analysis of Oil Supply System of a R134a Rotary Vane Compressor (R134a 로타리 베인 압축기 급유 계통 해석)

  • Kim, Ho-Young;Kim, Hyun-Jin
    • Proceedings of the SAREK Conference
    • /
    • 2008.11a
    • /
    • pp.113-118
    • /
    • 2008
  • For a R134a rotary vane compressor used for car air conditioners, characteristics of gas compression and oil supply have been studied. The compressor model under investigation has the low volume ratio of suction to discharge volumes so that there occur flow reversal from discharge port to compression chamber as the leading vane passes over the discharge port. As a result, the volumetric and adiabatic efficiencies turn out to be relatively low compared to other types of displacement compressors. Oil supply mechanism has been comprehended for mathematical modeling and oil flow rate has been calculated for the individual oil passages. This study on the gas compression and oil supply of a rotary vane compressor can be applied to a future design practice on a similar type of compressor.

  • PDF

A Study on the Plan of an Educational Curriculum for Reinforcement of Practical Education of Business Management (전문대학 경영학과의 실무교육강화를 위한 교육과정 개선방안)

  • 배수진
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.7 no.10
    • /
    • pp.35-45
    • /
    • 1984
  • 1. The purpose of the study. The purpose of this study is to suggest the direction of educational curriculum for reinforcement of practical education of business management department in technical college. 2. The method of the study (1) The consciousness investigation of an undergraduate (2) The demand and supply program of human power in enterprise (3) An opinion of enterprise (4) An opinion of professor and school career (specialist) (5) On-the-spot practice (6) An educational curriculum 3. The suggestion and conclusion (1) An enterprise should collect graduate of technical college at the rate of fixed as a foreign (2) An opportunity of a going education and of proceeding to higher school at the rate of fixed should be provided (3) Buss management department in technical college should be subdivided and specialized (4) Industrial - educational cooperation complex should be realized and promoted stroghly.

  • PDF

On the Abnormal Wear of Cylinder Liners and Piston Rings of the Marine Diesel Engine (박용(舶用) 디이젤기관(機關)의 실린더 라이너 및 피스턴 링의 이상마모(異常摩耗)에 관(關)하여)

  • Tae-Choon,Chung
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.8 no.1
    • /
    • pp.95-102
    • /
    • 1971
  • Since the fuel oil of the bunker C grade, which is commonly burnt in the large marine diesel engine, causes the corrosive wear of cylinder liners and piston rings, a cylinder oil of high alkality is frequently used to prevent the wear. This practice, however, brings us an another problem to cause the abnormal wear. In this study the author made an investigation of the mechanism of the abnormal wear by the experiments surveying the influences of the alkality of a cylinder oil and the temperature of cylinder wall on the wear. The major results obtained from this study are as follows; A cylinder oil of low alkality is clearly effective for the preventation of the abnormal wear. Therefore, it is recommended that, prio to using a cylinder oil of high alkality, a cylinder oil of low alkality should be used until bringing an end to the initial wear. It is also observed that the abnormal wear depends largely on the temperature of the cylinder wall, that is, the higher the temperature goes up the severer the wear grows.

  • PDF

Vehicle Load Effects on Slab of Parking Garage Structure (주차장 구조물 슬래브의 차량하중영향에 관한 연구)

  • 곽효경;송종영
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1997.04a
    • /
    • pp.131-138
    • /
    • 1997
  • The equivalent vehicle load factors which can consider the concentrated wheel load effect in slab design of parking garage structure are proposed. Based on the standard vehicle with total weight of 2.4 ton which is designed through the investigation of small to medium vehicle produced in Korea and the review of numerous foreign design codes for parking garage structure, the effects of moving vehicle loads on slab are analyzed using the finite element method. Besides. the relationships between the equivalent load factors and the sectional dimensions are established by regression analysis. The calculation of design forces can be easily accomplished without taking sophisticated numerical analysis for the moving vehicle load as the results obtained to the distributed load are multiplied by the proposed load factors in practice.

  • PDF

Why did the medical missionaries study traditional Chinese drugs in 19th century in China? (19세기 중국에서 활동한 의료선교사(醫療宣敎師)는 왜 중약(中藥)을 연구하였을까)

  • Jo, Jeong-Eun
    • The Journal of Korean Medical History
    • /
    • v.27 no.1
    • /
    • pp.77-86
    • /
    • 2014
  • The paper describes the practice and purpose of the medical missionaries research on the traditional Chinese drugs(中藥). Searches were made using the journal of the China Medical Missionary Association. The China Medical Missionary Association established the committee of the Chinese Materia Medica in 1890. This committee aimed to research on the traditional Chinese drugs. Then why did the medical missionaries study traditional Chinese drugs? This is because the western drugs(西洋藥)was not easy to acquire, especially in land areas. Also, some western drugs have poor quality and expensive. Therefore they need to understand that Chinese drugs will help in the production of the western drugs. But from around 1920, the main purpose of the research was changed. The scientific and systematic investigation on the Chinese medicine itself became more important. And this change partly influenced that medical missionaries' views on traditional Chinese drugs.

Drug Interaction Between Phenytoin and Diltiazem in Rabbit (딜티아젬과 페니토인과의 약물상호작용)

  • Choi, Jun-Shik;Chang, Il-Hyo
    • Journal of Pharmaceutical Investigation
    • /
    • v.23 no.1
    • /
    • pp.27-32
    • /
    • 1993
  • Pharmacokinetic drug interaction between phenytoin and diltiazem was investigated following i.v. administration concomitantly to rabbits. Diltiazem was coadministered at doses of 1, 2 and 3 mg/kg, respectively, with phenytoin (5 mg/kg) to rabbits. Plasma concentration and AUC of phenytoin were increased significantly, but volume of distribution and total body clearance were decreased significantly (p<0.05) at doses of 2 mg and 3 mg/kg of diltiazem. From the results of this experiment, it is desirable that dosage regimen of phenytoin should be adjusted and that therapeutic drug monitoring should be practiced for reduction of side or toxic effect when phenytoin should be administered with diltiazem in clinical practice.

  • PDF

Product Specification Management in Collaborative NPD: An Investigation of Problems and Good Practices in Electronics Industry

  • Lam, Ping-Kit;Chin, Kwai-Sang;Cheung, Wai-Ying
    • International Journal of Quality Innovation
    • /
    • v.7 no.1
    • /
    • pp.35-47
    • /
    • 2006
  • Client-supplier collaboration has been an imperative approach to new product development (NPD), in which a good product specification management system and practice is crucial to the assurance of product quality. This study investigates product specification management in client-supplier collaborative NPD. Based on the interviews and survey study, 12 problems and 13 good practices of product specification management are identified. It also compares the importance and degree of the implementation of the product specification practices in Hong Kong electronics industry. The results suggest that more intensive practices should be implemented for better product specification management.

Hypofractionated whole breast irradiation: new standard in early breast cancer after breast-conserving surgery

  • Kim, Kyung Su;Shin, Kyung Hwan;Choi, Noorie;Lee, Sea-Won
    • Radiation Oncology Journal
    • /
    • v.34 no.2
    • /
    • pp.81-87
    • /
    • 2016
  • Hypofractionated whole breast irradiation (HF-WBI) has been proved effective and safe and even better for late or acute radiation toxicity for early breast cancer. Moreover, it improves patient convenience, quality of life and is expected to be advantageous in the medical care system by reducing overall cost. In this review, we examined key randomized trials of HF-WBI, focusing on adequate patient selection as suggested by the American Society of Therapeutic Radiology and Oncology (ASTRO) guideline and the radiobiologic aspects of HF-WBI in relation to its adoption into clinical settings. Further investigation to identify the current practice pattern or cost effectiveness is warranted under the national health insurance service system in Korea.

Optimal Design of Dimension of Extrusion Die with Multi Stress Rings (다중보강링을 갖는 압출금형의 치수최적설계)

  • An, Sung-Chan;Im, Yong-Taek
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.10
    • /
    • pp.2211-2218
    • /
    • 2002
  • In this study, an optimal design study has been made to determine dimensions of die and multi stress rings for extrusion process. For this purpose, a thermo-rigid-viscoplastic finite element program, CAMPform, was used fur forming analysis of extrusion process and a developed elastic finite element program fur elastic stress analysis of the die set including stress rings. And an optimization program, DOT, was employed for the optimization analysis. From this investigation, it was found out that the amount of shrink fitting incurred by the order of assembly of the die set should be taken into account for optimization when the multi stress rings are used in practice. In addition, it is construed that the proposed design method can be beneficial fur improving the tool life of cold extrusion die set.

Investigation Problem-Solving in Virtual Spaces: The Knowledge Network of Experts (온라인 공간에서의 문제해결: 전문가 지식 네트워크에 관한 사례연구)

  • Koh, Joon;Jeon, Sungil
    • Knowledge Management Research
    • /
    • v.6 no.2
    • /
    • pp.149-168
    • /
    • 2005
  • Owing to the limits of IT System-driven knowledge management(KM) for innovation processes, alternative KM methods has been suggested such as: (1) the knowledge network of experts or (2) communities-of-practice. This study analyzes two cases in terms of on-line expert knowledge networks for problem-solving, with the dimensions of analysis based on a theoretical framework. By analyzing the cases of S company's expert network and Naver's Ji-sik-iN, we found that system quality(e.g., ease of use, accessibility, and searching function), information/knowledge quality(e.g., usefulness, accuracy, and timeliness), knowledge-sharing culture, social capital and relevant reward systems are important for stimulating a Q&A-based problem-solving knowledge network. Implications of the findings and future research directions are discussed.

  • PDF