• The Journal of Korean Association of Computer Education
• /
• v.19 no.2
• /
• pp.61-71
• /
• 2016

The purpose of this study was to identify problems of usability and to improve an interface in the digital textbook for leaner's leading to self-directed learning. To address those goals, the theory of affordance, which was related to affordance as leading to behavior, was applied for analyzing the user interface of digital textbook. Also, 10 students, 4th grade elementary school, were participated in the study. Participants were reported affordance's problems of digital textbook through Human Computer Interaction. As a result, some affordance's problems of the digital textbook were found out as follow; difficulty of page clicking, too small touch button, confusing the button, and, need to specific guidance. Based on the result, some suggestions were recommended to improve usability of digital textbook.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.466-471
• /
• 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
• /
• v.17 no.3
• /
• pp.60-69
• /
• 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
• /
• v.17 no.10
• /
• pp.1563-1571
• /
• 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.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.33
• /
• pp.63-89
• /
• 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
• /
• v.23 no.2
• /
• pp.93-107
• /
• 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
• /
• v.18 no.12
• /
• pp.2310-2318
• /
• 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.

• Food Science of Animal Resources
• /
• v.22 no.4
• /
• pp.363-372
• /
• 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.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.868-871
• /
• 2007

The current economy is summarized by increasing business competitiveness and leaner organizations, and the risk and uncertainties inherent in such dynamic environments have increased the importance of managing organizational knowledge. Like the preceding, the construction industry is required to make an effort for survival and takeoff, and most construction companies recognize that knowledge management improves efficiency and effectiveness and the necessity on the innovation of business itself and it is the current of the times. But at this point in time, companies have doubts about performance following the introduction of KM, and set to show interest in developing a measurement method. So, This study analyzes the existing model for performance measurement and based on results derived, presents the method for performance measurement.

• The Journal of the Korea Contents Association
• /
• v.20 no.11
• /
• pp.402-410
• /
• 2020

It is very important for Academic purpose Korean leaner to understand main ideas and overall context of texts. In order to understand the overall context and mail ideas of text, learners need output task, ways to perform what they are learning, such as retelling. That would help them to realize that there is a gap between what they have understood and what they can actually speak or write. These out activities help learners comprehend the text more efficiently, while at the same time raising their confidence level. The purpose of this study was to develop an education plan to improve reading comprehension ability by using retelling activity. To achieve the purpose of the study, retelling activity, which makes it easier to take an integrated approach to language function and is considered to be relatively effective, was utilized because of the characteristics of retelling activity education instead of teacher-centered education methods.