• 비파괴검사학회지
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• 제23권3호
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• pp.246-253
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• 2003

항공기 구조를 모사하여 일련의 리벳 구멍을 갖는 AA2024-T3 박판 구조를 대상으로 피로하중에 의한 단균열(short crack)의 발생시점과 성장거동을 음향방출(AE)을 위주로 한 측정으로 평가하였다. AE 위치표정에 의해 단균열의 좌표를 정확하게 결정하였으며, 이동식 현미경으로 균열의 크기를 측정하였다. 누적 AE 발생수 곡선은 단균열의 발생과 성장에 따라 일정한 간격을 두고 급격히 증가하는 양상을 보임으로써 여러 차례의 계단식 곡선을 형성하였다. AE 위치표정에서는 리벳 구멍을 중심으로 파괴역학에 근거한 관심영역(ROI)을 설정하였으며, 웨이블릿변환 잡음제거 방법을 사용하여 위치표정의 정확도를 향상할 수 있었다. 실제로 탐지된 신호의 대부분이 단 균열의 발생 및 성장과 관계없는 외부 잡음신호로 나타났으며, ROI 내에서 발생한 AE 발생원의 위치도 구조의 기하학적 특징이나 신호대잡음비의 영향에 의해 왜곡될 수 있음을 알 수 있었다.

• 대한건축학회논문집:계획계
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• 제34권12호
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• pp.85-94
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• 2018

The purpose of this paper was to propose a model that recognizes potential users' emotional response toward design by classifying Electroencephalography(EEG). Studies in neuroscience and psychology have made an effort to recognize subjects' emotional response by analyzing EEG data. And this approach has been adopted in design since it is critical to monitor users' subjective response in the preface of design. Moreover, the building design process cannot be reversed after construction, recognizing clients' affection toward design alternatives plays important role. An experiment was conducted to record subjects' EEG data while they view their most/least liked images of small-house designs selected by them among the eight given images. After the recording, a subjective questionnaire, PANAS, was distributed to the subjects in order to describe their own affection score in quantitative way. Google TensorFlow was used to build and train the model. Dataset for model training and testing consist of feature columns for recorded EEG data and labels for the questionnaire results. After training and testing, the measured accuracy of the model was 0.975 which was higher than the other machine learning based classification methods. The proposed model may suggest one quantitative way of evaluating design alternatives. In addition, this method may support designer while designing the facilities for people like disabled or children who are not able to express their own feelings toward alternatives.

• Asia Marketing Journal
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• 제16권4호
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• pp.19-37
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• 2015

Forming interfirm collaborative relationships has become a key aspect of a firm's marketing strategies to create value for customers and achieve greater firm performance. While empirical findings are mixed in previous studies, this study is an effort to identify boundary conditions for the benefits of marketing alliances. We investigate internal and environmental factors that may magnify or constrain the effect of marketing alliances on firm profitability. Given the complementary relationship between marketing and R&D activities, we focus on a firm's R&D intensity as an internal factor that may magnify the value of marketing alliances for firm performance. For environmental factors, we focus on industry turbulence and industry competitiveness. Industry turbulence refers to the degree to which industry market conditions change quickly and unpredictably, whereas industry competitiveness refers to the degree to which a firm faces competition in the industry. By testing these factors, we are intended to reveal boundary conditions that determine the value of marketing alliances for firm profitability. The analysis of firms in the diverse industries shows that while the main effect of marketing alliances on firm profitability is not significant, it becomes more positive when R&D investment is more intensive or when industry environment is more turbulent. The results of this study imply that just forming more marketing alliances may not be enough to increase firm profitability. Our findings imply that marketing alliances become more effective in a dynamically changing industry environment. That is, firms can cope with industry uncertainties more effectively by forming marketing alliances. At the same time, the moderating effect of R&D intensity implies that the internal investments in R&D magnify the effect of marketing alliances on firm profitability. The findings of this study contributes to the existing alliance literature in three aspects. First, this study enhances our understanding of the contingent value of marketing alliances by testing both internal and external factors that may influence the effectiveness of marketing alliances. Second, this study responds to the need for research that investigates actual performance resulting from interfirm relationships. Third, while previous studies primarily focused on a specific industry, this study extend previous findings of the boundary conditions for the benefits of marketing alliances in a broader context.

• 한국IT서비스학회지
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• 제12권1호
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• pp.271-287
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• 2013

The rapid growth and dissemination of touch-based mobile devices such as smart phones and tablet PCs, gives numerous benefits to people using a variety of multimedia contents. Due to its portability, it enables users to watch a soccer game, search video from YouTube, and sometimes tag on contents on the road. However, the limited screen size of mobile devices and touch-based character input methods based on this, are still major problems of searching and tagging multimedia contents. In this paper, we propose WalkieTagging, which provides a much more intuitive way than that of previous one. Just like any other previous video tagging services, WalkieTagging, as a voice-based annotation service, supports inserting detailed annotation data including start time, duration, tags, with little effort of users. To evaluate our methods, we developed the Android-based WalkieTagging application and performed user study via a two-week. Through our experiments by a total of 46 people, we observed that experiment participator think our system is more convenient and useful than that of touch-based one. Consequently, we found out that voice-based annotation methods can provide users with much convenience and satisfaction than that of touch-based methods in the mobile environments.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.431-438
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• 2011

To ensure that equipment outages do not directly impact the reliability of the ISO-controlled grid, market participants request permission and receive approval for planned outages from the independent system operator (ISO) in competitive electricity markets. In the face of major generation outages, the ISO will make a critical decision as regards the scheduling of the essential maintenance for myriads of generating units over a fixed planning horizon in accordance with security and adequacy assessments. Mainly, we are concerned with a fundamental framework for ISO's maintenance coordination in order to determine precedence of conflicting outages. Simulated annealing, a powerful, general-purpose optimization methodology suitable for real combinatorial search problems, is used. Generally, the ISO will put forward its best effort to adjust individual generator maintenance schedules according to the time preferences of each power generator (GENCO) by taking advantage of several factors such as installed capacity and relative weightings assigned to the GENCOs. Thus, computer testing on a four-GENCO model is conducted to demonstrate the effectiveness of the proposed method and the applicability of the solution scheme to large-scale maintenance scheduling coordination problems.

• 전기학회논문지
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• 제56권5호
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• pp.980-986
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• 2007

Boundary scan test structure(JTAG IEEE 1149.1 standard) that supports an internal scan chain is generally being used to test CUT(circuit under test). Since the internal scan chain can only have a single scan-in port and a single scan-out port; however, existing boundary test methods can not be used when multiple scan chains are present in CUT. Those chains must be stitched to form a single scan chain as shown in this paper. We propose an efficient boundary scan test structure that adds a circuit called Clock Group Register(CGR) for multiple clocks testing within the design of multiple scan chains. The proposed CGR has the function of grouping clocks. By adding CGR to a previously existing boundary scan design, the design is modified. This revised scan design overcomes the limitation of supporting a single scan-in port and out port, and it bolsters multiple scan-in ports and out ports. Through our experiments, the effectiveness of CGR is proved. With this, it is possible to test more complicated designs that have high density with a little effort. Furthermore, it will also benefit in designing those complicated circuits.

• Structural Engineering and Mechanics
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• 제51권6호
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• pp.989-1003
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• 2014

In the preliminary design stage of an RC 3D-frame, repeated sequential analyses to determine optimal members' sizes and the investigation of the parameters required to minimize the differential column shortening are computational effort consuming, especially when considering various types of loads such as dead load, temperature action, time dependent effects, construction and live loads. Because the desired accuracy at this stage does not justify such luxury, two backpropagation feedforward artificial neural networks have been proposed in order to approximate this information. Instead of using a commercial software package, many references providing advanced principles have been considered to code a program and generate these neural networks. The first one predicts the typical amount of time between two phases, needed to achieve the minimum maximorum differential column shortening. The other network aims to prognosticate sequential analysis results from those of the simultaneous analysis. After the training stages, testing procedures have been carried out in order to ensure the generalization ability of these respective systems. Numerical cases are studied in order to find out how good these ANN match with the sequential finite element analysis. Comparison reveals an acceptable fit, enabling these systems to be safely used in the preliminary design stage.

• 대한간호학회지
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• 제34권3호
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• pp.400-411
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• 2004

Purpose: This study was aimed to develop a computerized reminder system and evaluate it's effect in terms of percent age change of screening, and satisfaction. Method: It was conducted through 6 phases: Analyzing the job and defining the basic input data, developing the information system, collecting and inputting data, testing the system, working with the system, and evaluating it's effect. Participants were 787 people (female 30-69 years, and males 40-49 years) in 2 dong of Suyoung gu, Busan, who haven't had cancer screening for the stomach, breast, or cervix since Dec. 2000. There were three experimental groups: a letter; calling and calling after the letter reminder, and a non-equivalent control group. To determine whether services were obtained, a telephone survey was done after two months of follow-up. Result: A cancer screening information system with five DB modules was developed. Overall compliance with screening was not statistically significantly changedbefore and after applying computerized reminders for all three screening sites. Only 16% were satisfied with the reminder. Conclusion: This data didn't show that a reminder effort was effective of screening. However, because the evaluation interval was too short to find a difference in screening rate, we recommend additional longer prospective follow up studies.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권1호
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• pp.1-17
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• 2017

The purpose of this study is to analyze the differences between the cognitive load of mathematics textbooks based on storytelling and traditional mathematics textbooks that are presented to students. In order to verify this, we have selected two 4th grade classes in elementary school that were identified as a homogeneous group through prior testing, and thus were separated into experimental group and comparative group. Then, without the teacher's lessons, the experimental group learned from mathematics textbooks based on storytelling and the comparative group learned from traditional mathematics textbooks. Afterwards, the two groups' cognitive load was measured through a questionnaire, and the following results were obtained: In the 'mental effort' and 'self evaluation' categories, the students that learned from the mathematics textbook based on storytelling showed higher scores than the students that learned from the traditional mathematics textbook. also there was statistically significant difference in some items. However, no statistically significant difference was found in the remaining categories 'task difficulty', 'self evaluation', and 'material design'.

• Computers and Concrete
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• 제19권3호
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• pp.293-303
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• 2017

Maximum deflection in a beam is a serviceability design criterion and occurs generally at or close to the mid-span. This paper presents a methodology using neural networks for rapid prediction of mid-span deflections in reinforced concrete beams subjected to service load. The closed form expressions are further obtained from the trained neural networks. The closed form expressions take into account cracking in concrete at in-span and at near the interior supports and tension stiffening effect. The expressions predict the inelastic deflections (incorporating the concrete cracking) from the elastic moments and the elastic deflections (neglecting the concrete cracking). Five separate neural networks are trained since these have been postulated to represent all beams having any number of spans. The training, validating, and testing data sets for the neural networks are generated using an analytical-numerical procedure of analysis. The proposed expressions have been verified by comparison with the experimental results reported elsewhere and also by comparison with the finite element method (FEM). The proposed expressions, at minimal input data and minimal computation effort, yield results that are close to FEM results. The expressions can be used in every day design since the errors are found to be small.