• Title/Summary/Keyword: lean

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Effects of Intake and Exhaust Valve Timing on Combustion and Emission Characteristics of Lean-Burn Direct-Injection LPG Engine (직접분사식 희박연소 LPG엔진에서 흡배기 밸브시기가 연소 및 배기특성에 미치는 영향)

  • Park, Cheolwoong;Kim, Taeyoung;Cho, Seehyoen;Oh, Seungmook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.1
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    • pp.45-51
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    • 2015
  • In order to meet the enforced emission regulations and reduce fuel consumption, various new technologies are employed in engines. The problem of NOx emissions under a lean mixture condition should be solved, because a lean-burn direct-injection engine can realize stable lean combustion with a stratified mixture, which results in improvements in fuel economy and emissions. This study investigated the effects of intake and exhaust valve timing changes on the performance and emission characteristics of a lean-burn LPG direct-injection engine. Under a partial-load operating condition without throttling, an increase in the intake valve opening led to an increase in NOx emissions due to an increase in the amount of excess air. The fuel consumption deteriorated with an increase in the exhaust valve opening due to a decrease in the expansion work and an increase in the pumping loss.

Study of Combustion Characteristics with Compression Ratio Change in Ultra-Lean LPG Direct Injection Engine (압축비 변화에 따른 초희박 직접분사식 LPG엔진의 연소특성 연구)

  • Cho, See Hyeon;Yoon, Jun Kyu;Park, Cheol Woong;Oh, Seung Mook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.10
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    • pp.837-844
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    • 2014
  • Automotive manufacturers have recently developed various technologies for improving fuel economy and satisfying enhanced emission regulations. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of ignition. A conventional LPG engine has been redesigned to an ultra-lean-burn LPG direct injection engine in order to adopt combustion system of ultra-lean-burn. This study is aimed at investigating the effect of a change in the compression ratio on the performance and emission characteristics of a lean-burn LPG engine. The fuel consumption, heat release rate, combustion pressure, and emission characteristics are estimated depending on changing the effect of compression ratio. When the compression ratio is increased, it is difficult to improve the fuel consumption owing to an unstable combustion state, but the total hydrocarbon and nitrogen oxide emissions are reduced.

Positive Effects of Diphlorethohydroxycarmalol (DPHC) on the Stability of the Integument Structure in Diet-Induced Obese Female Mice

  • Kim, Chae-lim;Cha, Sun-yeong;Chun, Min Young;Kim, Bumsoo;Choi, Min Young;Cheon, Yong-Pil
    • Development and Reproduction
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    • v.19 no.3
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    • pp.145-152
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    • 2015
  • Diphlorethohydroxycarmalol (DPHC) is a known to modulate the expression of extracellular matrix (ECM) components in 3T3-L1. However, the possible role of DPHC in integument stability during obesity induction is not clear yet. We evaluated the effects of DPHC on collagen or elastic fiber quantity in integument during obesity induction with high-fat diet. The dorsal back integument sections were stained with hematoxylin-eosin, Masson trichrome, and Verhoff-Van Gieson. The intensities of collagen fibers and elastin fibers were analyzed with ImageJ. The number of fibroblasts was counted at ${\times}1,000$ fields. The number of fibroblast was increased by obesity induction, but DPHC suppressed it in a concentration-dependent manner both in lean and obese mice. On the other hand, the intensities of collagen fibers were increased by DPHC treatment in obese mice groups but not in lean mice groups. The intensities of collagen fibers of obese mice were lower than that of the lean mice in 0% group. However, the number became similar between lean and obese mice by the treatment of DPHC. The intensity of elastic fibers was increased in the lean mice with the concentration of DPHC. In the obese mice group, there were increasing patterns but only significant at 10% DPHC group. The intensity of elastic fibers of obese mice was higher than lean mice in 0%, 1%, and 10% groups. Histologically epithelial cells and follicle cells which were diffused nuclear staining forms were increased by DPHC treatment. The results suggest that the activity of integument cells during obesity induction can be modulated by DPHC.

Survey on Hanwoo Usage and Menu Development using Lean Cut Hanwoo for School Foodservice (학교급식의 한우 이용실태 조사 및 저지방 한우 부위를 이용한 학교급식 메뉴 개발)

  • Jeong, Hee Sun;Lee, Tae Nam;Yoon, Ji Young
    • The Korean Journal of Food And Nutrition
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    • v.26 no.4
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    • pp.620-632
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    • 2013
  • The purpose of this study is to analyze Hanwoo usage in school foodservices and to develop menus of lean cut Hanwoo. As a result, satisfaction of students, parents and teachers all increased regardless of school type after using Hanwoo. The high price compared to other meats (3.98) was the biggest difficulty for using lean cut Hanwoo followed by reduced taste preferences (2.84), lack of parent awareness (2.67) and lack of appropriate cooking facilities (2.13). According to the survey on how to increase the usage of lean cut Hanwoo, improvement of meat tenderness (3.80), development of various sauces (3.74) and development of seasoning for existing menu (3.61) were identified as major necessities. This analysis of Hanwoo utilization in school foodservice was used to develop menus of lean cut Hanwoo. The menu was particularly developed to overcome the supply-demand imbalance of different cuts. For the menu development process, potential Hanwoo utilization in school foodservice, cooking method, and diverse taste were considered. In order to evaluate the applicability in school foodservice, JARS was used and the final eight menus were selected. For the selected menu, a nutrition analysis was conducted. Further, systematic recipes with a mixing ratio;product process description and a simplified product process were also developed.

Effect of Estrone Treatment on Proteinuria in Maturing Lean and Obese Male SHR/Mcc-cp Rats (Estrone 투여가 SHR/Mcc-cp 계통의 정상체중과 비만한 성장기 숫쥐들에서 단백뇨 증상에 미치는 영향)

  • Park, Sonhee
    • Journal of Nutrition and Health
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    • v.23 no.6
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    • pp.451-458
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    • 1990
  • Lean and obese male spontaneously hypertensive(SHR/Mcc-cp) rats were fed a ground rat chow diet with or without 0.001% estrone added from 6 to 18 weeks of age. Urine samples were collected weekly with 24 hour fasting. Both control lean and obese rats showed significantly higher urinary protein than their estrone treated counterparts. Treatment with 0.001% estrone diet was found to reduced the proteinuria in the maturing lean and obese SHR/Mcc-cp rats. Peaks in urinary protein level were noted at 16 weeks of age in both lean and obese control rats. Both control and estrone treated lean rats showed higher proteinuria than the obese rats. Therefore, obesity does not appear to be a contributing factor to the proteinuria in young male SHR/Mcc-cp rats.

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The Level of Serum Cholesterol is Negatively Associated with Lean Body Mass in Korean non-Diabetic Cancer Patients

  • Han, Ji Eun;Lee, Jun Yeup;Bu, So Young
    • Clinical Nutrition Research
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    • v.5 no.2
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    • pp.126-136
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    • 2016
  • Due to poor nutrition and abnormal energy metabolism, cancer patients typically experience the loss of muscle mass. Although the diabetic conditions or dyslipidemia have been reported as a causal link of cancer but the consequence of such conditions in relation to gain or loss of skeletal muscle mass in cancer patients has not been well documented. The purpose of this study was to investigate the relationship of lean body mass and systemic parameters related to lipid metabolism in non-diabetic cancer patients using data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2011. As results the level of serum total cholesterol (total-C) was negatively associated with both total lean body mass and appendicular lean body mass in cancer patients after adjustment for sex, physical activity, energy intake and comorbidity. The associations between consumption of dietary factors (energy, carbohydrate, protein and fat) and lean body mass were disappeared after adjusting comorbidities of cancer patients. Multivariate-adjusted linear regression analysis by quartiles of serum total-C showed that higher quartile group of total-C had significantly lower percent of lean body mass than reference group in cancer patients. The data indicate that serum lipid status can be the potential estimate of loss of skeletal muscle mass in cancer patients and be referenced in nutrition care of cancer patients under the onset of cachexia or parenteral/enteral nutrition. This data need to be confirmed with large pool of subjects and should be specified by stage of cancer or the site of cancer in future studies.

Analysis of Body Composition according to Short Distance and Middle & Long Distance of Youth National Athletic Athletes (꿈나무 국가대표 육상선수들의 단거리, 중장거리 종목에 따른 신체 조성 분석)

  • Kim, Hyun-Chul;Park, Ki-Jun
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.1
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    • pp.33-39
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    • 2021
  • PURPOSE: This study compared the body composition according to the sport of short-distance and middle & long-distance athletes to identify the factors that affect the body composition. METHODS: Forty-eight athletes selected as youth national athletes in 2019 participated in the study. The study participants measured the length of the lower extremities, body composition, and anaerobic ability. An independent sample t-test was conducted to compare the body composition according to the event. In addition, the Pearson correlation was performed to identify the factors that influence the body composition. RESULTS: The leg length of the Short and Middle & long-distance athletes were similar (p = .584). On the other hand, there were differences in the body fat percentage (p = .001), lean percentage (p = .001), and BMI (p = .001). In addition, the body fat percentage was correlated with the lean body mass (r = .419) and BMI (r = .447). Furthermore, the lean body mass was correlated with the BMI (r = .849) and the peak power (r = .662) and mean power (r = .686) of the anaerobic capacity. Moreover, the BMI was correlated with the peak power (r = .490) and mean power (r = .543) of the anaerobic capacity. The peak power of the anaerobic ability was correlated with the mean power (r = .931). CONCLUSION: The body composition differed according to the sport. The body fat percentage correlated with the lean body mass and the BMI. The lean body mass correlated with the BMI, peak power of anaerobic ability, and mean power. The BMI correlated with the anaerobic capacity.

A Case Study on the Lean Management Activity in Business-Services Industry (사무.서비스 산업의 린 경영 활동에 관한 사례 연구)

  • Lee, Kang-In;Lee, Soon-San
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.1
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    • pp.189-206
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    • 2012
  • It is urgently requested to innovate the management process of business-service areas in all industry such as financial business, services and manufacturing because of recent business trend - de-manufacturing trend and the weight increment of service in all industries. Many enterprises introduce various management - innovation methodologies in order to meet the rapidly changing business environment. Especially in Korea, it is a vogue to introduce the innovation methodology of the advanced company's. According to this style, the six sigma has been introduced over 10 years since late 1990's and it has become a synonym of innovation indeed. But the result of six sigma introduction has not reached to the level of expectation in its beginning. And the "Lean" have been introduced in Korea in the situation of global financial crisis, economic slump and the pursuit of developing country such as China. Many Korea companies pay attention to the "Lean" innovation activity because the TPS(Toyota Production System) is the matrix of Lean and is the motive power of Toyota growth. In this study, it was analyzed for the evolution course, distinctive features and effects of Lean management and was examined for the difference of Lean management between manufacturing industry and business-service areas. From this results, the characteristics of Lean management in business-service was analyzed. After survey of innovation agent in Korea company, the Lean model of business-service Industry was developed and applied. This study will be worthy to show the right direction to the enterprises which are to apply lean methodologies, or the enterprises which examine lean management for competitive advantages or the peoples who research the same topics.

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Effects of Oenanthe javanica, Coicis lachryma-jobi L. var., and Plantaginis asiatica L. Water Extracts on Activities of Key Enzymes on Lipid Metabolism (미나리 줄기(Oenanthe javanica), 율무(Coicis lachryma-jobi L. var.), 차전자(Plantaginis asiatica L.) 물 추출물이 지질대사)

  • Lee, Hyeon-Ju;Chung, Mi-Ja;Kim, Dae-Jung;Choe, Myeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.11
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    • pp.1516-1521
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    • 2009
  • This study was carried out to estimate beneficial effects of medicinal plant [Oenanthe javanica (MNR), Coicis lachryma-jobi L. var. (YM), Plantaginis asiatica L. (CJJ)] water extracts on activities of key enzymes such as lipoprotein lipase (LPL), acyl-CoA synthetase (ACS) and carnitine acetyltransferase (CAT) on lipid metabolism. LPL and ACS were extracted from the epididymal adipose tissue and liver of Zucker lean rats (lean) and Zucker fatty rats (fa/fa). MNR or YM water extract treatment significantly reduced the activity of lean and fa/fa LPL. When 10000 ppm of MNR, YM, and CJJ water extracts were tested, they decreased fa/fa LPL activity by 32.5%, 30.1% and 22.8%, respectively. The lean ACS activity was significantly higher in YM water extract treatment compared to the control and the MNR water extract treatment significantly increased the activity of fa/fa ACS, compared to the activity in the control (p<0.05). MNR water extract activated fa/fa ACS activity by 12-fold compared with control at 10000 ppm concentration. CAT activity was significantly higher in 10000 ppm and 20000 ppm CJJ water extract treatment than in the control. Thus, the MNR, YM and CJJ water extracts may have beneficial effects due to activities of enzymes related with fat metabolism in obese humans.

An Empirical Study on the Alternative Work Organization and Workers' Outcome - Focus on Lean Production - (대안적 작업조직 유형과 노동자 성과에 관한 실증적 고찰 - 제조업의 린 방식을 중심으로 -)

  • Son, Dong-Hui
    • Korean Journal of Labor Studies
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    • v.17 no.1
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    • pp.1-36
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    • 2011
  • The purpose of this study is to analyze the effect to financial outcome and workers' outcome, using the manufacturing industry database of Human Capital corporate Panel from Korea Research Institute for Vocational Education & Training. Especially, this study used the typology of Lean production and Autonomous team production, that are the typical form of alternative work organization, to analyze. In the case of domestic manufacturing industry, individual participation practices, that have the main characteristics such as QC or suggestion system, is expanded. Therefore, with the reference of Lean production, Autonomous Team Production and the Taylor system are compared and analyzed, considering the characteristics of Socio-technical System. As a result, it is showed that the Lean production and Autonomous Team Production as a alternative work organization are more positive about the organizational performance and workers' outcome than the taylor system. However, when Lean production and Autonomous Team Production are compared, it is showed unsignificant distinction to the effect of organizational performance. Meanwhile, Lean production showed more negative effect on the every dependent variables such as working hours, income, job satisfaction, and organizational commitment as workers' performance than the Autonomous Team Production. Although the common ideas and belief is that the Lean Production is superior for the quality and organizational performance improvement, it is implied the possibility that there is some damaged workers' performance on the hidden side of that mechanism.