• 컴퓨터교육학회논문지
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• 제19권2호
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• pp.61-71
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• 2016

본 연구의 목적은 학습자가 디지털교과서를 보다 능동적으로 학습하고 자기주도적으로 사용할 수 있도록 사용성과 관련된 어포던스(행동유도성)의 문제점을 파악하고 이를 개선하고자 하는데 있다. 이를 위해 초등학교 4학년 학생 10명이 과업을 통해 관찰 및 면담을 통해 어포던스 문제점을 살펴보고 그에 맞게 실질적으로 인터페이스를 개선하였다. 이러한 개선을 통해 학습자들이 정보를 바로 지각, 이해 할 수 있도록 하여 학습자가 디지털교과서라는 낯선 디지털 환경에서도 학습자들이 적절하게 행동이 유도될 수 있을 것이며 디지털교과서로 어떠한 환경에서도 학습자들이 직접 조작하고 상호작용하는 학습 체험을 경험하고 의미 있는 학습으로 연계될 수 있을 것이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.466-471
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• 2004

In gas turbines, excess air for combustion is available and therefore lean premixed combustion is the most promising approach to the significant reduction of thermal NOx emissions. At lean conditions, however, flame stability is inherently worse and hence combustion tends to be incomplete. Efforts have been devoted toward extending the operating range of complete combustion at leaner conditions. One of them is the lean-lean two-stage combustion where lean to ultra-lean secondary mixtures are mixed with the hot burned gas from the primary stage. Conventional flame combustion or flameless reaction are initiated depending on the conditions of the secondary zone. In the first part of the present study, the effects of fuel injection on the emissions and flame stability were investigated for a single tubular flame, In the second part, the emissions and flame stability were studied for a two-stage combustor with secondary mixture injected through the tangential slots on a cylindrical combustor wall. The effects of the ratio of air flow rates to the primary and secondary zones on the emissions and combustion characteristics were investigate.

• Journal of Advanced Marine Engineering and Technology
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• 제17권3호
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• pp.60-69
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• 1993

The speed control associated with dc servo motors for direct-drive applications of mobile robot is considered in this study. Robot is moved by power wheeled steering of two dc servo motors mounted to it. In order to cooperate with micro-computer and to achieve the high-performance operation of dc servo motor, speed control system is composed of a digital Phase Locked Loop and H-type drive circuit. And the motor is driven by Pulse Width Modulations. In controlling PWM, it is modified to compose of H-type drive circuit with feedback diodes and switching transistor and design of control sequence so that it may show linear characteristics. As a result, speed characteristics of motor showed linear features. In order to get data on design of PLL control system, the parameters of 80[W[ motor & robot device is measured by simple software control. The PLL speed control system is schemed and designed by leaner drive circuit and measured parameters. A complete speed control system applied to 80[W] dc servo motor showed good linearity, stability and high response. Also, it is verified that the PLL speed control system has good compatibility as a mobile robot driver.

• Journal of Mechanical Science and Technology
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• 제17권10호
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• pp.1563-1571
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• 2003

A fast response NO analyzer was applied to investigate the relation between cycle-by-cycle NO emissions and combustion chamber pressure. NO emissions were sampled at an isolated exhaust manifold of 4-stroke spark ignition engine to avoid the interference of exhaust gas from other cylinders. The linear correlation analysis was performed with collected data of NO emissions and combustion chamber pressure with respect to the various air-fuel mixture ratios and engine loads. The sampled data sets were obtained during 200 cycles at each operating condition. The results showed that there was a typical pattern in NO emissions from an exhaust port through a cycle. It was possible to set a block of crank angle in which the linear correlation coefficient between NO emissions and combustion chamber pressure was high. As the engine load increased, NO emissions were more dependent on combustion chamber pressure after TDC. It was also analyzed that the correlation between two parameters with respect to air-fuel mixture ratio tended to increase as mixture went leaner. Furthermore, this correlation coefficient for the mixture near the lean limit seemed to be kept high even though combustion was unstable.

• 무역상무연구
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• 제33권
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• pp.63-89
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• 2007

The UCP is an authoritative compilation of the customs and practice of letters of credit observed by most of the participants in the transaction. It remains the most successful set of private rules for trade ever developed. First issued in 1933, the UCP has been through five revisions, the latest being the present UCP 500, which came into force in 1994. Since 1994, new developments in transport, insurance, electronic commerce and banking industry have spurred the current revision of the rules. The ICC Banking Commission approved UCP 600 on October 25, 2006 by a unanimous vote of 91 to 0. The revision, which will come into effect on July 1, 2007, incorporates a number of changes from UCP 500 as follows : UCP 600 has a leaner set of rules, with 39 articles rather than 49 articles of UCP 500; New sections on "definitions" and "interpretations" have been added to clarify the meaning of ambiguous terms; The phrase "reasonable time" for acceptance or refusal of documents has been replaced by a firm period of five banking days; UCP 600 allows for the discounting of deferred payment credits. However, UCP 600 has two main problems such as the inconsistency with insurance industry and the banking community-oriented rules. We have some months before the commencement of UCP 600. From today to the commencement of UCP 600, we should study the full contents of UCP 600 and the influences on the trade industry.

• Journal of Nutrition and Health
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• 제23권2호
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• pp.93-107
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• 1990

The purposes of this investigation were to determine the validity of various methods (available anthropometric equations and near-infrared light interactance) for estimating body fat and to develop multiple regression equations for the prediction of body fat. Thirty-eight healthy males(age: 20.87$\pm$7.17 yrs) and 12 females(19.58$\pm$2.19 yrs) underwent hydrostatic weighing to determine body fat. Anthropometric measurements were taken of height, weight, nin skinfolds and thirteen circumferences. The results obtained are summarized as follows: 1) Relative body fat determined by underwater weighing was 12.08$\pm$5.21% for the males and 17.97$\pm$5.75% for the females. 2) Circumference and skin fold that had the highest correlation with the body fat were waist girth in males and females(r=0.60, r=0.96, respectively), and subscapular in males(r=0.68) and triceps in females(r=0.96). 3) Corss-validation of 18 selected equations on males revealed total errors ranging from 3.76% to 5.06%. Among these equations, M3(Pollock et al.) demonstrated the least total error. Total error of estimation by near-infrared(NIR) was less than that of available anthropometric measurement equations. The results of the cross-validation of 12 equations on females revealed that F3(Sloan et al.) was clearly superior in accuracy of prediction. 4) Correlational analyses showed that estimation of body fat by NIR measurement seemed to be more closely associated with body fat determined by underwater weighing in women than men, in older subjects than younger ones, and in fatter subjects than leaner ones.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2310-2318
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• 2004

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 400 bar to 800 bar by using a common rail injection system. Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

• 한국축산식품학회지
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• 제22권4호
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• pp.363-372
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• 2002

Reducing the fat content of processed meat products can be performed by (1) using leaner raw meat materials (2) inducing non-meat ingredients that serve to replace a portion or all of the fat, and (3) applying new ingredient combinations, technologies or processing procedures that decrease the fat and cholesterol content of meat products. Low-fat meat products were manufactured with Int replacers which were food ingredients that had the functional and sensory properties of fat without contributing fat calories, resulting in lower fat(<3%) content. Added water, non-meat proteins, carbohydrates, such as starch and hydrocolloids(gums) and vegetable oils have been used as typical fat replacers to be used in meat products. In addition, fat substitutes included structural lipids, sucrose polyester and ingredient combinations. Formulations for the manufacture of low-fat meat products in combined with new technologies have focused on the use of fat replacer combinations that contributes a minimum of calories and not detrimental to flavor, juiciness, mouthfeel or textural traits expected more traditional products. In conclusion, some combinations of fat replacements that mimics the flavor, mouthfeel and textural characteristics of fat offer potential for further development of low-fat meat products to have similar characteristics of regular-fat counterparts.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.868-871
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• 2007

현대 경제는 치열한 경쟁, 군살 없는 조직, 광범위한 기술의 발전 등으로 요약될 수 있고, 이러한 역동적인 환경 속에서 리스크와 불확실성은 조직 지식관리의 중요성을 더욱 부각시키고 있다. 건설 산업도 예외일 수 없으므로 생존 및 도약을 위한 다양한 노력을 요구하고 있고 지식경영을 통한 효율성 및 효과성의 향상과 업무 자체의 혁신에 대한 필요성은 모든 건설기업이 주지하고 있는 사실이며 시대의 큰 흐름이라고 할 수 있다. 그러나 지식경영이 일정 부분 정착된 현 시점에서 기업들은 지식경영 도입에 따른 성과에 대해 의구심을 가지고, 평가 도구 개발에 관심을 가지기 시작했다. 이에 본 연구는 기존의 지식경영 성과측정 모델을 검토 및 분석하여 그것을 토대로 성과측정 방법론을 제시하고자 한다.

• 한국콘텐츠학회논문지
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• 제20권11호
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• pp.402-410
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• 2020

학문 목적 한국어 학습자에게 읽기 능력은 수업에서 강의를 듣거나 보고서를 쓰는 등의 활동의 기본이 되기 때문에 상대적으로 더 중요하다고 볼 수 있다. 그런 이유에서 학문 목적 한국어 학습자들에게 읽기 능력의 향상은 한국어 습득에서 중요하다. 이러한 읽기 능력의 향상을 위해 출력가설을 이해하고 다시 말하기 활동을 제안하여 실제 수업에 적용하고자 한다. 출력은 보통 말하고 쓰는 능력의 향상을 위해 목표 언어를 발화하는 기회를 많이 주는 것을 강조하는 가설로 인식되곤 한다. 그러나 읽기 능력의 향상에 있어서도 출력활동의 효율성은 검증되고 있고 계속 연구되어 오고 있다. 출력은 학습자들이 스스로 발화하도록 돕고 자신의 발화를 통해 목표언어와의 차이를 인지하게 함으로써 지식을 내재화시킬 수 있도록 한다. 이에 본 연구에서는 출력가설의 한 활동으로 다시 말하기 활동을 제안하여 읽기 능력을 향상시킬 수 있는 수업 모형을 설계하는 것을 목표로 한다. 또한 수업 모형을 적용한 실제 수업의 예를 보여줌으로써 실제 수업에서의 적용 가능성 또한 보여주고자 한다.