• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권8호
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• pp.368-374
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• 2002

In this paper, we introduce a procedure to obtain a equivalent circuit of comb-line band pass filter. By employing equivalent circuits of each asymmetrical coupled line. we composed the full equivalent circuit of comb-line bandpass filter and derived simple design equations for extracting each line's impedance. To show the validity of design equations, we simulated and fabricated a planar type comb-line bandpass filter, which has center frequency 1.8㎓, band-width 50㎒ and four resonators. The resulting filter is very compact, have broad stop band with the second pass band centered at four times the center frequency of the first pass band. The experimental results show exact performances of design specification.

• 대한전기학회논문지
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• 제31권7호
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• pp.11-17
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• 1982

In this paper, a reliable and convenient evaluation method for the adequacy of any radial distribution line's voltage drop is proposed for improvement of the voltage regulation of the distribution line under operation. Using the voltage measurement of the first load branch point and the last point on the given distribution line its average line voltage drop and the line voltage drop variance by pure load variation are computed. And by these values and allowable or required line drop from proper voltage regulation view point, present adequency index and operation improvement index of the line drop are newly introduced for the evaluation of the given distribution line's voltage regulation. As a result of application to the 4 cases of study, the proposed method is proved to be reliable and convenient.

• 수산해양교육연구
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• 제22권3호
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• pp.316-329
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• 2010

The purpose of this study was to examine how middle school students perceived the operation of on-line and off-line math-gifted education. The research questions were as follows: 1. How do students recognize the current situation concerning the operation of on-line and off-line gifted education? 2. How do students recognize the effect and satisfaction level of on-line and off-line gifted education? 3. How do students recognize the improvement of on-line and off-line gifted education? The subjects in this study were 591 students who included 208 in on-line classes and 383 in off-line classes. The results were as follows: First, the students who were enrolled in the on-line and off-line classes regarded gifted people as ones who had a superb ability in a particular field and as ones who think creatively. Second, all the students in on-line and off-line classes found gifted education to be of use to developing their potentials, and they had the biggest preference for experiential field study as the most effective teaching method. Third, concerning their needs for the management of gifted classes, they asked for immediate Q&A services over the Internet.

• 말소리와 음성과학
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• 제2권3호
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• pp.11-22
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• 2010

The present study attempts to investigate declination in Korean and its relevant aspects to the length of utterance, the clause boundary, and focus. More specifically, I examine the relation of declination with the length of utterance, the declination reset at the clause boundary, and the effect of focus on declination. Results showed that the length of utterance had no relation with the first and last pitch values of the utterance but that they were consistent regardless of the length of utterance. However, the declination slope changed to be relatively gentle from the fourth accentual phrase to the end of the whole intonational phrase. There was a reset of declination in such a way that the first pitch in the second phrase was always lower than that of the first phrase, but the first pitch in the third phrase was not always lower than that of the second phrase when the whole utterance was composed of three phrases. Finally, the pitch values of the focusing words decreased as their position went back in a sentence. One declination line was formed in the case of focused utterance, but in the case of an utterance that contained a clause boundary, a new declination line was formed at the start of each new clause. These findings can be applied to developing a Korean speech synthesizer that contains natural prosody; they can be also utilized for teaching Korean prosody.

• 패션비즈니스
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• 제7권4호
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• pp.26-42
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• 2003

On-line clothes sale are on the increase, and the returns(for replacements or refunds) of the clothes are also increasing. Many studies on off-line consumers' complaints were made before, but few studies on the returns of clothes sold on-line have been made. From this viewpoint, this study was conducted to know what effect returns of clothes sold on-line have on their brands. Therefore, this study was first focused on the factors affecting complaint acts(return intention or return acts) such as lack of information and recognition of product, delivery errors and product defects concerning on-line sales, and second investigated the changes of buyers' attitude toward the brand following the their acts of returning the buyers, and third looked into the changes of on-line buyers' attitude toward the brand. The study is carried out by subdividing the objects of the study into return action(replacement, refundment) and purchasers who experienced return intention. Such experience is demonstratively analyzed to find how it has affected the attitude toward the brand. The study comes up with the following outcomes. First, the effect factor causing complaint action(return action, return intention) on-line is shown as the lack of the information and recognition of the product. Second, it is revealed that the effect factor causing complaint(return action, return intention) does not lie in an error in delivery or a defect of a product. Third, the positive response of a brand to a return action does not raise the repurchasing intention and positive attitude of purchasers who experienced returning a product, but lowers their private complaint action intention. Fourth, the repurchase intention of purchasers who experienced return intention for the brand is lowered, but their negative attitude and private complaint action intention is not raised.

• Journal of Gastric Cancer
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• 제21권3호
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• pp.268-278
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• 2021

Purpose: While several prognostic models for the stratification of death risk have been developed for patients with advanced gastric cancer receiving first-line chemotherapy, they have seldom been tested in the Chinese population. This study investigated the performance of these models and identified the optimal tools for Chinese patients. Materials and Methods: Patients diagnosed with metastatic or recurrent gastric adenocarcinoma who received first-line chemotherapy were eligible for inclusion in the validation cohort. Their clinical data and survival outcomes were retrieved and documented. Time-dependent receiver operating characteristic (ROC) and calibration curves were used to evaluate the predictive ability of the models. Kaplan-Meier curves were plotted for patients in different risk groups divided by 7 published stratification tools. Log-rank tests with pairwise comparisons were used to compare survival differences. Results: The analysis included a total of 346 patients with metastatic or recurrent disease. The median overall survival time was 11.9 months. The patients were different into different risk groups according to the prognostic stratification models, which showed variability in distinguishing mortality risk in these patients. The model proposed by Kim et al. showed relative higher predicting abilities compared to the other models, with the highest χ² (25.8) value in log-rank tests across subgroups, and areas under the curve values at 6, 12, and 24 months of 0.65 (95% confidence interval [CI]: 0.59-0.72), 0.60 (0.54-0.65), and 0.63 (0.56-0.69), respectively. Conclusions: Among existing prognostic tools, the models constructed by Kim et al., which incorporated performance status score, neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, and tumor differentiation, were more effective in stratifying Chinese patients with gastric cancer receiving first-line chemotherapy.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1936-1942
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• 2009

Shinbundang-line is new Metropolitan Railway which was invested by private capital and is under construction for opening in 2010. Now Shinbundang-line pursues various innovation, for example, an express train which uses long distance of each station, and an unmanned operation. And it may be independent of existing metropolitan railway system from a viewpoint of line and fare system. So according to the present plan, Shinbundang-line will be not able to get sufficient demand because of weak connection with existing lines and monotonous function of the line. And it may be difficult to deliver various innovation which Shinbundang-line prepares to passengers. Hereupon, in this paper, I propose 3 methods for increasing competitive power of Shinbundang-line railway. First, making Shinbundang-line a trunk railway line of southern metropolitan area was proposed in relation to northern and southern extension of it. In addition connection with bus and light rail was discussed. Second, multipurpose usage of Shinbundang-line was proposed as express train and conventional passenger train in that line in addition to simple metropolitan railway. Finally, an effective operation method which Shinbundang-line must have was proposed from unmanned driving and fare system side. These methods can improve Shinbundang-line and then it will solve traffic congestion of southern metropolitan area effectively.

• 대한인간공학회지
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• 제15권1호
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• pp.1-14
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• 1996

Menu-driven interfaces are frequently employed for user interfaces on many electronic products. Due to space constraint, a single or multi-line display is popularly used to show menu items unlike the software interfaces. Single or multi-line display present 8 .approx. 21. characters on an LCD screen and the user selects items using a series of button pushes. Multi-line displays are different from the single-line ones in the following aspects. First, they can present multiple line of information at the same time. Second, they can present menu items in a various way compared to single-line ones. However, due to their space constraint multi-line displays have many limitations compared to ordinary displays which usually use 14" screens. Therefore, guidelines are necessary for designing efficent multi-line display menus interfaces. In this study, a human factors experiment was conducted to examine the effects of three design variables which might affect the usability of a multi-line display menus. Factors investigated include menu structure, number of lines on the display, and item presentation method. Usability of the multi-line display menus was measured quantitatively in terms of four different aspects: speed, accuracy, inefficiency and preference. The analysis of variance was used not only to analyze the main effects of the factors and their interactions but also to see the differences between the single-line display menus and multi-line display ones. A set of design guidelines drawn from this study can be applied to the design of the user interfaces of a various types of electronic consumer products.

• 산업경영시스템학회지
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• 제3권3호
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• pp.35-39
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• 1980

Although the product line produces a large volume of goods in a relatively short time, once the product line is established there are numerous problems that arise in connection with this product line. One of these problems is the problem of balancing operations or stations in terms of equal times and in terms of the times required to meet the desered rate of production. The objective of line balancing is minimizing the idle time on the line for all combinations of work stations subject to certain restrictions. In general, there are two types of line-balancing situations : (1) assembly line balancing and (2) fabrication line balancing. Two approaches to the assembly line balancing problem have been used. The first assumes a filed cycle time and find the optimum number of work stations. The second approach to the assembly line balancing problem assumes the number of work stations to be fixed and systematically coverages on a solution which minimizes the total delay time by minimizing the cycle time. Here the cycle time is determined by the longest station time. In this paper, by using the second approach method, a general mathematical model, problem solutions, and computer program for the assembly line balancing problem is presented. Data used is obtained from the company which has been confronted with many problems arising in connection with their assembly line.

• 비파괴검사학회지
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• 제32권4호
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• pp.347-354
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• 2012

Using a single-line pulsed laser beam is well known as a useful noncontact method to generate a directional surface acoustic wave. In this method, different laser beam energy profiles produce different waveforms and frequency characteristics. In this paper, we considered two typical kinds of laser beam energy profiles, Gaussian and square-like, to find out a difference in the frequency characteristics. To achieve this, mathematical models were proposed first for Gaussian laser beam profile and square-like respectively, both of which depended on the laser beam width. To verify the theoretical models, experimental setups with a cylindrical lens and a line-slit mask were respectively designed to produce a line laser beam with Gaussian spatial energy profile and square-like. The frequency responses of the theoretical models showed good agreement with experimental results in terms of the existence of harmonic frequency components and the shift of the first peak frequencies to low.