• 한국분무공학회지
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• 제14권4호
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• pp.171-177
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• 2009

This study proposes a new stratified charge system for low emission and ultra lean burn. In order to examine combustion characteristics of the new system, sparkplug with a hole at positive pole and a common CNG injector for injecting fuel were used in this study as injector-type spark plug. The new stratified charge system injects fuel of extremely small quantities and ignites mixture around sparkplug gap. Also, the system was fitted in a visualized constant volume chamber. Then, for analysis of the combustion characteristics, we examined combustion pressure, lean inflammable limit, and visualized combustion flame according to equivalence ratio by comparison with homogeneous charge (HC) method and the new stratified charge (SC) method. As results of this study, in the case of using this system, the propagation speed of initial flame was increased and total combustion period was reduced in the ultra lean burn in the same equivalence ratio. These phenomena occurred clearly under the conditions of lean equivalence ratio. Furthermore, the lean inflammable limit of mixture was extended by using the injector-type spark plug.

• 대한안전경영과학회지
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• 제14권2호
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• pp.147-158
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• 2012

This paper aims to develop a new chain metrics for obtaining lean Overall Equipment Effectiveness(OEE) and present implementation strategy which considers the properties for Total Productive Maintenance(TPM) to reduce machine losses, Performance Analysis and Control(PAC) to reduce labor losses, Lean Production System(LPS) to reduce floor wastes, and Theory of Constraints(TOC) to minimize the problem of Capacity Constrained Resource(CCR). The study reviews the related literatures and reformulates the structure of machine losses, labor losses and field wastes. The research also develops the integrated productivity metrics according to time, units, reliability and maintainability. It is found that the study develops the actual productivity measure in terms of efficiency, effectiveness and standard productivity. In addition to that, it outlines and develops by using the integrated LPS and TPM, lean OEE measures such as Time Based Productivity(TBP), Unit Based Productivity(UBP), and Reliability & Maintainability Based Availability(RMBA). Implication examples are proposed to make it easier and available for practioners to understand the implementation strategies about TPM OEE, lean OEE and TOC OEE. Futhermore related to other studies, the research contributes to create a new chain productivity measures to clear the interrelationship concepts of productivity, efficiency and effectiveness. Moreover the paper develops the enhanced OEE measures by integration of TPM, PAC, LPS and TOC with the perspective of schedule, throughput, reliability, maintainability and availability.

• 한국전문물리치료학회지
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• 제30권1호
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• pp.8-14
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• 2023

Background: Excessive hamstring (HS) activation due to the weakness of the gluteus maximus (GM) causes pain in the hip joint. A single-leg deadlift is a hip extensor exercise, especially GM, that includes functional movements in daily life and complex multi-joint training. In single-leg deadlift, the muscle activity depends on the forward trunk lean angle, and it's necessary to study which muscles are used dominantly depending on the angle. Objects: The purpose of this study was to compare the effect on the muscle activity of the GM and HS during single-leg deadlift according to different forward trunk lean angles and the ratio of the GM vs HS (GM/HS). Methods: Twenty-one healthy female participants were recruited. The muscles activities of the GM, HS and the GM/HS ratio were measured through electromyography during single-leg deadlift according to three condition of forward trunk lean angles (30°, 60°, and 90°). Results: The GM and HS activities significantly differed among three conditions (p < 0.05). GM/HS ratio was significantly higher at 30° and 60° of forward trunk lean compared to 90°. Moreover, the GM activity was significantly higher at 60° of forward trunk lean than at 30° (p < 0.05). Conclusion: The single-leg deadlift at 60° of forward trunk lean is a proper GM muscle strengthening exercise.

• 대한의용생체공학회:의공학회지
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• 제28권5호
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• pp.628-635
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• 2007

We studied the effect of vibratory stimulations of different leg muscles, tibialis anterior(TA) and triceps surae(TS), and plantar zones in ten healthy subjects during 1) quiet standing, 2) forward lean of body, 3) backward lean of body, 4) right lean of body, and 5) left lean of body. The experiments were performed on the force platform. The effect of vibration were measured by monitoring the area of COP(Center of pressure) sway. The subjects wore a vibratory stimulation system on foot and ankles and were given the instruction not to resist against the applied perturbations. The results show that all vibratory stimulations to lower limb muscles and plantar zones reduced the COP sway area. This reduction of the COP sway area occurred also in partial vibratory stimulations during quiet standing. In forward lean of body, vibratory stimulations to TA reduced the COP sway area. During backward lean of body, vibratory stimulations to TS reduced the COP sway area. When the subject was tilted right, vibratory stimulations to left plantar zone reduced the COP sway area. During left lean of body, vibratory stimulations to right plantar zone reduced the COP sway area. Thus, the influence of vibratory stimulations to leg muscle and plantar zones differed significantly depending on the lean of body. We suggest that the vibration stimuli from leg muscles and plantar zones could be selectively used to help maintaining postural balance stable.

• 융합보안논문지
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• 제8권1호
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• pp.101-108
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• 2008

본 연구에서는 항만 물류 프로세스의 현황과 장애요인을 분석하고, Lean이론을 적용한 프로세스의 재설계를 통해 이를 개선하기 위한 방안을 도출하는 한편, 개선된 프로세스를 통한 항만물류시스템을 구축하기 이전 과정을 철강기업 내에 특화된 부두 운영 업무 중 슬라브 관리업무에서 항만물류프로세스의 관련 주체를 선별하고 각 주체간의 관계를 파악하여 부두, 조업, 출하, 공정, 품질, 구매에 이르는 관리업무를 정의하고 각각 개체사이의 정보와 슬라브의 흐름에서 Lean 도구를 사용하여 기존 프로세스 상에 Value added와 Non-Value added를 분석하여 Cycle Time의 감소, 재고감소, 업무전환시간의 감소, 재작업감소, 서비스개선, 낭비 감소 등을 목표로 업무프로세스를 정형화시키고, 항만현장이 항만물류프로세스를 최적의 상황으로 실행 할 수 있도록 환경의 재설계를 통한 항만물류프로세스의 개선된 모델을 제시한다.

• 한국식품영양학회지
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• 제27권4호
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• pp.650-659
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• 2014

The purpose of this study was to analyze Hanwoo usage in restaurants and to develop menus of lean cut Hanwoo. Restaurant served customers Hanwoo menus, with the exception of broiled or roasted meat, mainly to provide various menus to customers (4.14), due to customer needs (3.87) and utilizing stocks (3.59). On the other hand, the reason for not providing Hanwoo menus, with the exception of broiled or roasted meat was manpower shortage (3.63), lack of popularity (3.58), low profit (3.29), preservation of Hanwoos' original flavors (3.28) and complex cooking methods (3.22). Concomitantly, the restaurant owners' intentions to apply new menus with lean cut Hanwoo was 73.4%, showing an interest in developing new menus and recipes using lean cut Hanwoo suitable to the changing owner awareness of customer health and trends. This study has established a standard for developing cooking methods and developed menus according to classified recipes for lean cut Hanwoo, based on the survey of restaurants' current status of using Hanwoo and the owners' opinions. 20 menus using lean cut Hanwoo (rump or shank) were developed by $1^{st}$ and $2^{nd}$ cooking experiments, and in-depth interview of experts-groups. Of these, 12 menus suitable for the restaurant were finally selected based on the results of consumer's evaluation using JARS. Structured recipe flow diagram and recipe instructions were developed for future semi-processed or processing foods. Diverse recipe methods using lean cut Hanwoo were obtained from the study, however aggressive public relations work is required for promoting the developed menus.

• 벤처창업연구
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• 제10권5호
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• pp.63-71
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• 2015

린 6시그마 또한 6시그마처럼 도입하고자 하는 조직의 특성에 맞게 불합리한 사항과 미비사항을 사전의 파악하여 보완하지 않고, 조직의 특성과 기본 여건을 고려하지 않은 상태에서 추진되어진다면 아마도 추진 사무국 및 전담자의 과중한 업무가 하나 더 늘어나는 결과를 초래할 수 있으므로 린 6시그마 문헌연구와 적용구축 사례 분석과 현재까지 지속적으로 6시그마 활동을 10년 이상 추진 중인 15개 업체에 소속된 벨트(MBB, BB) 96명으로부터 접수된 설문지 내용을 조사하여 얻어진 자료를 통계분석 프로그램인 SPSS 16.0을 사용하여 설문자료의 신뢰성과 타당성을 분석하였고, 6시그마 추진 시행성과, 6시그마 프로젝트 개선안 실행력 제고방안, 6시그마 추진 시 발생하는 당면한 문제점과 개선 및 보완사항을 파악하여 기존 6시그마에 린 생산방식을 합리적으로 통합시켜 린 6시그마 도입 시 경영혁신을 위한 린 6시그마 활동의 효과적인 전개 방법을 제안하였다.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.179-189
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• 2008

The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/$\gamma-Al_2O_3$ with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of $NO_2$ to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to $N_2$, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring $350^{\circ}C$ and with a maximum breakthrough time occurring $400^{\circ}C$ at all GHSVs investigated in this study. Also, maximum ratio of $NO_2$ to NO is obtained at $400^{\circ}C$ with a GHSV of $75,000\;hr^{-1}$ Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of $H_2$ and 4% of CO in the rich phase is found to be optimum at operating temperature of $350^{\circ}C$ and a GHSV of $50,000\;hr^{-1}$.

• Journal of Animal Science and Technology
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• 제63권2호
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• pp.332-338
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• 2021

The objective of this study was to predict body compositions of live pigs using bioelectrical impedance procedures. In experiment 1, 32 crossbred (Duroc × Landrace × Yorkshire) finishing pigs with an average weight at 84.06 kg were used. In experiment 2, 96 crossbred (Duroc × Landrace × Yorkshire) finishing pigs with an average weight at 88.8 kg were used. A four-terminal body composition analyser was utilized to determine fat percentage. Lean meat percentage and backfat thickness were measured with a lean meat measuring meter. In experiment 1, fat percentage was not significantly correlated with lean meat percentage, although a tendency (p < 0.1) of a negative correlation was found. Backfat thickness was significantly correlated with fat percentage and lean meat percentage (r = 0.745 and r = -0.961, respectively). Coefficients of determination for fat percentage with lean meat percentage, fat percentage with backfat thickness, and backfat thickness with lean meat percentage were 0.503, 0.566, and 0.923, respectively. In experiment 2, fat percentage was significantly correlated with lean meat percentage (r = -0.972). Backfat thickness was also significantly correlated with fat percentage and lean meat percentage (r = 0.935 and r = -0.957, respectively). Results of this study indicate that bioelectrical impedance analysis might be useful for predicting body compositions of live finishing pigs.

• International Journal of Automotive Technology
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• 제2권4호
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• pp.147-155
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• 2001

Analysis of the thermodynamic cycle of IC engine from the point of view of economy and emissions was carried out. From this analysis potential capability of engine development was derived. This potential capability is lean-burn engine, fuelled with homogeneous mixture with $\lambda \geq$ 1.4. Several different modes of fuelling were proposed and tested on one-cylinder test engine from the point of view of extending lean operating limit of the engine, emissions and fuel economy. Among them were: fuelling with evaporated preheated gasoline, with gas (LPG evaporated) and with liquid butane. From these modes, fuelling with liquid butane injected to inlet port was selected and finally tested. This novel system of fuelling offered better than standard engine performances and emissions at lean operating limit. These results were validated on full-scale two-cylinder engine.