• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.151-168
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• 2022

Nowadays companies are required to achieve social goals beyond maximizing shareholder profits. Accordingly, it is important to pursue both the economic and social goals of a company at the same time. Thus the importance of hybrid organizations is increasing theoretically and practically. In particular, since hybrid organizations essentially have the complexity of pursuing both economic and social purposes, the institutional demands of various stakeholders surrounding hybrid organizations are also conflicting. Several previous studies have considered how hybrid organizations respond to these conflicting institutional demands, but most studies are limited to studying at a specific point in time. As a result, there was a limit to analyzing the dynamics in response to conflicting institutional demands as the hybrid organization expanded its business. This study predicted that the hybrid organization would take selective coupling with conflicting institutional demands and that the process of responding to institutional demands would change according to the organization's growth. In this study, we had a case study about Noul and Enuma, social ventures that operate relatively advanced business models with outstanding results in innovation and technology. As a result, social ventures show a selective coupling for conflicting institutional demands, and the selective coupling process changes as their business model are advanced. Specifically, in the early stages of the business, it appears to respond to economic and social demands at the same time with a single business model. When the business is advanced, two or more business models are operated, some of which respond to economic needs and some of which respond to social needs. In the early stages of business, social ventures respond to economic and social demands with a single business model to gain legitimacy and survive in the institutional demands. But when they enter the business growth period, they try to separate business models which respond to economic and social values because they pursue sustainable growth and challenge large-scale missions. Overall, this study attempted to contribute to an in-depth understanding of hybrid organizations by identifying that the method of responding to conflicting institutional demands varies depending on the growth process of social ventures.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.299-306
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• 2009

Purpose : To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Materials and Methods : Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation ($0.625\;mm{\times}64\;ea$), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of $40{\sim}80%$ of R-R interval and 120mA(80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. Results : The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with that of conventional coronary CTA. And heart dose was 33.8 mGy, this represents 67.4% reduction. In the sequential scan technique under prospective ECG gating with low kVp the mean effective dose was 3.0 mSv, this represents an 83.2% reduction compared with that of conventional coronary CTA. And heart dose was 17.7 mGy, this represents an 82.9% reduction. Conclusion : In coronary CTA at retrospectively ECG gated helical scan, cardiac dose modulation technique using low kVp reduced dose to 50% above compared with the conventional helical scan. And the prospectively ECG gated sequential scan offers substantially reduced dose compared with the traditional retrospectively ECG gated helical scan.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.43-53
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• 2019

This study has explored the trajectory of the development and diffusion of the CTLs in the Korean universities by using isomorphism theory of neo-institutionalism. Neo-institutional theorists believe that organizational structure and behavior reflects the norms and values recognized in the society rather than the organization's autonomous and rational choices. Based on the isomorphism framework, the introduction and diffusion of the CTLs in the Korean universities have been led by the government. In addition, the CTLS(Korean Association of Center for Teaching & Learning) has served as a direct basis for the normative pressures. In other words, the CTLs have been securing devices for the universities to acquire external justification by the environment, and they have been able to confirm that the system was isomorphed, in particular by meeting and agreeing with the government-set university evaluation criteria. Efforts should be made to develop unique values and strategies that enable CTLs to become engines of the development of university education in response to rapid changes in the academic environment.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.191-194
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• 2005

본 논문은 최적 탐색 알고리즘인 유전자 알고리즘을 이용하여 다항식 뉴럴네트워크(Polynomial Neural Networks : PNN)의 최적 설계가 그 목적이다. 기존의 다항식 뉴럴네트워크는 확장된 GMDH(Group Method of Data Handling) 방법에 기반을 두며, 네트워크의 성장과정을 통하여 각 층의 다항식뉴런(혹은 노드)에서 고정된 (설계자에 의해 미리 선택된) 노드 입력들의 수뿐만 아니라 다항식 차수(1차, 2차, 그리고 수정된 2차식)를 이용하였다. 더구나, 그 방법은 학습을 통해 생성된 PNN이 최적 네트워크 구조를 가진다는 것을 보증하지 못한다. 그러나, 제안된 GA-based PW 모델은 다음의 파라미터들- 즉 입력변수의 수, 입력변수, 및 다항식 차수-을 유전자 알고리즘을 이용하여 선택 동조함으로써 그 구조를 구조적으로 더 최적화된 네트워크가 되도록 하고, 기존의 PNN보다 훨씬 더 유연하고, 선호된 뉴럴 네트워크가 되도록 한다. 하중계수를 가진 합성성능지수가 그 모델의 근사화 및 일반화(예측) 능력 사이의 상호 균형을 얻기 위해 제안된다. GA-based PNN의 성능을 평가하기 위해 그 모델은 가스 터빈발전소의 NOx 배출 공정 데이터로 실험된다. 비교해석은 제안된 GA-based PNN이 앞서 나타난 다른 지능모델보다 더 우수한 예측능력뿐만 아니라 높은 정확성을 가진 모델임을 보인다.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.204-215
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• 2020

We analyze changes of consumption behavior for bundle services for the latest three years focusing on comparing the detailed service types and service providers to understand competition structure in the market. Our major findings and implications are as follows. First, the mobile telecommunication service is certainly deemed to be a major selection criteria for bundling service provider, therefore the leading company in the mobile telecommunication has become more significant market power. Second, IPTV has an important influence for slection of bundling service provider, lately in some cases, rather than broadband Internet. Third, the individual services affecting the selection of bundling service providers clearly showed differentiation among three operators as a mobile telecommunication service of SK Group, a broadband Internet of KT, and an IPTV of LGU+. In addition, the importance of individual services in securing subscribers has been increased as the preference factors to switch a service provider were synchronized with the decision of major bundling service provider. Finally, although it is difficult to find customers' lock-In due to the latest change of their intentions to switch a provider, we find it is continuously necessary to monitor customers' lock-in as there are more long-term customers with re-contracts. Our results provide the policy implications based on the change of competition structure and usage behavior in the bundle market which is not evaluated the competiton situation.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.737-742
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• 2007

The concept of 'Picturing' is beyond the 'Illusion' of traditional art in the Digital Media era. It is a 'Suffering' of the 'Re-appearance' that is masquerade the 'Actual' as a 'Digital Apparition.' This study aims to concern the point of view on the above subject; the 'Picturing' through the analysis of communication problems in the digital era. To begin with, need to define the concept of 'Picturing' and how it is expected to have a role through the accessibility of medium use, intervention by body and images. Also, I suggest a new approach to 'Picturing' as a new mutual communication method. Body, Digital media, and Image. These three principles of 'Picturing' create huge benefits to our world/nature whether we want it or not. It seems to become more and more of powerful self-replicating organism. We have to be aware what sort of images are surrounding us and how transmitting it to where in/on our body via newest sophisticated media we use. 'Picturing' is an invasion of ordinary, no longer exists pleasure for body, no longer speaks intension of its next destination. It strongly self-grows and also controls us in the name of Digital media era. However, 'Picturing' is a mode of re-imaging activity and also suggestion of re-appearance practice.

• Progress in Medical Physics
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• v.7 no.2
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• pp.79-90
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• 1996

In this paper, we present an automatic threshold decision method to detect the contour of the a 2-D echocarodiogram by using the Bayes estimator for the boundary-like region. The boundary-like region is constructed from the conduction coefficient of the heat anisotro-pic diffusion method which enforces the blurred image during the preprocessing step. For the boundary-like region, we used the Bayes estimator to select an optimal threshold level. From this threshold value, the contour of the echocardigrams can be detected automatically Finally by overlapping the estimated contour to the original echocardiogram, we can obtain the contour enforced ultrasound echocardiogram.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.23-43
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• 2009

This study examined the relativity between school uniform behavior(especially attitude toward school uniform, school uniform satisfaction, school uniform alteration) and attitude toward appearance in the adolescence. From November to December in 2007, 898 middle school and high school students from four schools in Jeollabuk-do Province were analyzed and the influence of relevant variables was understood to gather basic information about the fashion life in the adolescence. This study used SPSS 11.5 for Windows Program to conduct frequency analysis, factor analysis, reliability analysis, ${\chi}^2$-test, t-test, One-way ANOVA, Duncan's multiple comparison test, and Pearson's correlation. The following summarizes the findings of this study: The results of analysing the factors to the response attitude toward uniforms and attitude toward appearance and clothing attitude emerged four dimensions(fashion, symbolism, cleanliness, alternation), three dimensions(needs value conformity toward appearance). In attitude toward uniform, female students were more actively altering their uniforms than male students and middle school students were more sensitive to trends than high school students. However, high school students were more aware of the cleanliness and alteration of uniforms. Overall, most students were not very satisfied with their uniforms (design, color, texture). When students' attitude toward appearance and demographical characteristics were examined, it was found that female students were more aware of desire, value, and conformity in appearances than male students. By age, it was found that high school students were more aware than middle school students. Also, students receiving KRW 30,000 or more for monthly allowance were more aware than others who receive a lower amount between KRW 10,000 and KRW 20,000. Therefore, most students(62.1%) have experiences in altering uniforms. Especially, more female students and more high school students had such experiences. Uniform alteration is more related to attitude to appearance. In other words, students who choose to alter their uniforms are highly aware of desire, value, and conformity toward appearance. Students who are satisfied with all factors regarding attitude toward uniform, except for alteration, did not alter their uniforms that much. In addition, when the relativity between students' attitude toward appearance with uniform was considered, students that are not very satisfied with their uniforms were more aware of desire, value, and conformity toward appearance. In conclusion, it was found that students' attitude toward appearance and school uniform behavior are closely related and their interests in appearance lead to alteration of uniforms, the clothing in which they spend most time of the day. From now on, students' opinions shall be considered when selecting or designing school uniforms.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.438-445
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• 2007

A Helmholtz resonator as a stabilization device to control high-frequency combustion instabilities in liquid rocket engine is adopted and its damping capacity is verified by linear acoustic analysis and atmospheric acoustic tests. To compare the results of acoustic attenuation effect in accordance with uni-resonator's geometry, quantitative analyses were made in the cases of various orifice diameters and lengths. Next, in the experiments to compare the results of acoustic attenuation effect by a difference in the number of resonators, damping capacity of harmful resonant frequency was improved by the increase of the number of resonators. On the other hand, attenuation efficiency of the frequency tended rather to lower due to over damping from the point of view of absorption coefficient. As the result, tuning the suitable geometry for the resonator to the resonant frequency is required for the control using the resonator. Also, the design of resonator's geometry and the choice of its number are important to put up the optimal efficiency in consideration of restriction of its volume.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.846-851
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• 2005

In this paper, we propose Genetic Algorithms(GAs)-based Optimized Polynomial Neural Networks(PNN). The proposed algorithm is based on Group Method of Data Handling(GMDH) method and its structure is similar to feedforward Neural Networks. But the structure of PNN is not fixed like in conventional neural networks and can be generated in a dynamic manner. As each node of PNN structure, we use several types of high-order polynomial such as linear, quadratic and modified quadratic, and it is connected as various kinds of multi-variable inputs. The conventional PNN depends on the experience of a designer that select the number of input variables, input variable and polynomial type. Therefore it is very difficult to organize optimized network. The proposed algorithm leads to identify and select the number of input variables, input variable and polynomial type by using Genetic Algorithms(GAs). The aggregate performance index with weighting factor is proposed as well. The study is illustrated with tile NOx omission process data of gas turbine power plant for application to nonlinear process. In the sequel the proposed model shows not only superb predictability but also high accuracy in comparison to the existing intelligent models.