• Journal of the Korea Concrete Institute
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• v.24 no.1
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• pp.25-35
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• 2012

For a member subjected to direct shear forces, forces are transferred across interface concrete area and resisted by shear transfer capacity. Shear-friction equations in recent concrete structural design provisions are derived from experimental test results where shear-friction capacity is defined as a function of steel reinforcement area contained in the interface. This empirical equation gave too conservative values for concrete members with large amounts of reinforcement. This paper presents a method to evaluate shear transfer strengths and to define ultimate conditions which result in crushing of concrete struts after yielding of longitudinal reinforcement perpendicular to the interface concrete. This method is based on the bi-axial stress field theory where different constitutive laws are applied in various means to gain accurate shear strengths by considering softening effects of concrete struts based on the modified compression-field theory and the softened truss model. The validity of the proposed method is examined by applying to some selected test specimens in literatures and results are compared with recent design code provisions. A general agreement is observed between predicted and measured values at ultimate loading stages in initially uncracked normal-strength concrete test.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.03a
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• pp.175-186
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• 1999

Detecting the features of significant patterns from their own historical data is so much crucial to good performance specially in time-series forecasting. Recently, a new data filtering method (or multi-scale decomposition) such as wavelet analysis is considered more useful for handling the time-series that contain strong quasi-cyclical components than other methods. The reason is that wavelet analysis theoretically makes much better local information according to different time intervals from the filtered data. Wavelets can process information effectively at different scales. This implies inherent support for multiresolution analysis, which correlates with time series that exhibit self-similar behavior across different time scales. The specific local properties of wavelets can for example be particularly useful to describe signals with sharp spiky, discontinuous or fractal structure in financial markets based on chaos theory and also allows the removal of noise-dependent high frequencies, while conserving the signal bearing high frequency terms of the signal. To data, the existing studies related to wavelet analysis are increasingly being applied to many different fields. In this study, we focus on several wavelet thresholding criteria or techniques to support multi-signal decomposition methods for financial time series forecasting and apply to forecast Korean Won / U.S. Dollar currency market as a case study. One of the most important problems that has to be solved with the application of the filtering is the correct choice of the filter types and the filter parameters. If the threshold is too small or too large then the wavelet shrinkage estimator will tend to overfit or underfit the data. It is often selected arbitrarily or by adopting a certain theoretical or statistical criteria. Recently, new and versatile techniques have been introduced related to that problem. Our study is to analyze thresholding or filtering methods based on wavelet analysis that use multi-signal decomposition algorithms within the neural network architectures specially in complex financial markets. Secondly, through the comparison with different filtering techniques results we introduce the present different filtering criteria of wavelet analysis to support the neural network learning optimization and analyze the critical issues related to the optimal filter design problems in wavelet analysis. That is, those issues include finding the optimal filter parameter to extract significant input features for the forecasting model. Finally, from existing theory or experimental viewpoint concerning the criteria of wavelets thresholding parameters we propose the design of the optimal wavelet for representing a given signal useful in forecasting models, specially a well known neural network models.

• Journal of Korean Academy of Nursing
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• v.50 no.1
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• pp.66-80
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• 2020

Purpose: This study aims to examine the effects of nursing interventions based on the Extended Theory of Planned Behavior (ETPB) regarding self-efficacy for exercise (SEE), physical activity (PA), physical function (PF), and quality of life (QOL) in patients with lung cancer who have undergone pulmonary resection. Methods: This quasi-experimental study was conducted between July 2015 and June 2018 in two university-affiliated hospitals. The intervention included pre-operative patient education, goal setting (action and coping planning), and feedback (behavior intention and perceived behavioral control). The intervention group (IG) (n=51) received nursing interventions from the day before surgery to 12 months after lung resection, while the comparison group (CG) (n=36) received usual care. SEE, PA, PF (dyspnea, functional status, and 6-minute walking distance [6MWD]), and QOL were measured before surgery and at one, three, six, and 12 months after surgery. Data were analyzed using the χ² test, Fisher's exact test, Mann-Whitney U test, t-test, and generalized estimation equations (GEE). Results: There were significant differences between the two groups regarding SEE (χ²=13.53, p=.009), PA (χ²=9.51, p=.049), functional status (χ²=10.55, p=.032), and 6MWD (χ²=15.62, p=.004). Although there were no time or group effects, the QOL mental component (Z=-2.78, p=.005) of the IG was higher than that of the CG one month after surgery. Interventions did not affect dyspnea or the QOL physical component. Conclusion: The intervention of this study was effective in improving SEE, PA, functional status, and 6MWD of lung cancer patients after lung resection. Further extended investigations that utilize ETPB are warranted to confirm these results.

• Korean Journal of Comparative Education
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• v.24 no.3
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• pp.199-226
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• 2014

The aim of this study was to determine key experiences of homestay guardians of unaccompanied minor Korean adolescents studying abroad in the United States through qualitative research method of grounded theory methodology. This study identified guardianship experiences and the process of adjustment to life with homestay students through in-depth interviews with 12 subjects who are Korean guardians in the United States. The results of this study classified "started with concern" as a category that leads guardians to start providing homestay accommodation, and "other's recommendation," "need for financial support," and "unexpectedly" as subcategories. This study identified "act as a mediator to resolve differences" as a key experience of guardians, and classified subcategories are "parental role" and "calculation of gains and losses" on a personal level; and "feel sorry for own children," "limited leeway of the family," and "formation of relationship between own children and homestay students" on a family level. Developed subcategories are "thirsty for attention," "vulnerability," "task on freedom and control," and "regrettable feeling in the absence of communication" with respect to relationship with students; "grade expectations," "one-way communication," "trapped between parents' and students' demands" in regard to relationship with parents; and "advice from school" in the aspect of school. "Cultural difference," "preparedness of students and parents," "age differences between guardian's children and students," "family support," "similar personalities," "guardian's motivation," and "parent's attitude" are subcategories that affect central phenomenon of guardians.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.3
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• pp.145-158
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• 2021

The purpose of this study is to examine the influence of the ownership structure of unlisted firms on KOSDAQ listing. There are few studies analyzing the characteristics of listing success based on ownership structure. For startup executives, there is not enough data to refer to the ownership structure that can increase the possibility of listing. This paper examines the effects of ownership structure on IPO success through comparison between listed successful and failed companies among the companies in application for KOSDAQ listing eligibility review. The major findings are as follows; (1) Venture capital investment and shareholding have a statistically positive effect on the success of KOSDAQ listing. This results indicate that the venture capital's investment alleviate the problem of information asymmetry, and it is a valid signal for market participants. The result means the role of venture capital seems to be important when companies are listed on the KOSDAQ. (2) The largest shareholder's stake has an inverted-U shape relationship with listing success. In other words, the ownership concentration mitigates moral hazard problem, which leads to listing success. However, if the ownership concentration exceeds a certain level, the chances of success in listing will decrease due to concerns over the pursuit of private interests. The result suggests that the largest shareholder's stake reduce agency problem. This study academically contributes to the existing literature by demonstrating the ownership structure affects IPOs, and explaining the results based on agent theory and signal theory. Our results provide practical implications for companies preparing for an IPO on the KOSDAQ.

• Journal of Technology Innovation
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• v.30 no.1
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• pp.21-56
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• 2022

Since Michael Porter (1991) has proposed that environmental regulation can help a firm increase its competitiveness by encouraging it to engage in more innovative activities to meet the environmental regulation, a number of researchers have empirically investigated the "Porter Hypothesis." However, the empirical results still remain mixed. Combining the perspectives of the behavioral theory of the firm and firm heterogeneity, we argue that the levels of regulation stringency and time-pressure would differentially influence a firm's innovative behavior depending on the firm's aspiration level, performance feedback and technological capabilities. Using the U.S. Corporate Average Fuel Efficiency (CAFE) regulation context, we empirically demonstrate that lagging firms that do not meet the new regulation standard announced by the government tend to search for more distant knowledge and that the impact of the patents they file for decreases as the regulation becomes more stringent. In addition, we also find that as time-pressure increases, lagging firms stand to apply for more patents than do leading firms whereas the overall impact of the patents decreases. These results help us advance our understanding of the nuanced causal relationship between regulation and innovation and provide practical implications for policymakers.

• The Journal of Art Theory & Practice
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• no.16
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• pp.107-137
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• 2013

This paper examines a number of Korean artists-Whanki Kim, Po Kim, Byungki Kim, Lim Choong-Sup, Min Byung-Ok and etc-working in New York in the 1960s and 1970s, focusing on their motivations to head for the U.S. and their life and activity in the newly-emerged city of international art. The thesis was conceived based upon the fact that New York has been one of the major venues for Korean artists in which to live, study, travel and stay after the Korean War. Moreover, the United States, since 1945, has had a tremendous influence upon Korea politically, socially, economically, and, above all, culturally. This study is divided into three major sections. The first one attends to the reasons that these artists moved out of Korea while including in this discussion, the long-standing yearning of the Korean intelligentsia to experience more modernized cultures, and American postwar cultural policies that stimulated them to envision life beyond their national parameters, in a country heavily entrenched in Cold War ideology. The second part examines these artists' pursuit of abstraction in New York where it was already losing its avant-garde status as opposed to the style's cutting edge cache in Korea. While their turn to abstraction was outdated from New York's critical perspective, it was seen to be de rigueur for Koreans that had developed through phases from Art Informel in the 1960s to Dansaekhwa (monochromatic paintings) in the 1970s. The third part focuses on the artists' struggle while caught between a dualistic framework such as Korea/U.S, East/West, center/margin, traditional/modern, and abstraction/figuration. Despite such dichotomic frames, they identified abstract art as the epitome of pure, absolute art, which revealed their beliefs inherited from western modernism during the colonial period before 1910-1945. In fact, their reality as immigrants in America put them in a diasporic space where they oscillated between the fixed, essentialist Korean identity and the floating, transforming identity as international artists in New York or Korean-American artists. Thus their abstract and semi-abstract art reflect the in-between identity from the diasporic space while demonstrating their yearning for a land of political freedom, intellectual fulfillment and the continuity of modern art's legacy imposed upon them over the course of Korea's tumultuous history in the twentieth century and making the artists as precursor of transnational, transcultural art of the global age in the twenty-first century.

• Journal of Korean Library and Information Science Society
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• v.8
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• pp.127-154
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• 1981

Today's complicated society with a rapid change needs more objective and accurate data for the better managerical decisions and the prospect for the future other than the intuition or subjective experience by men themselves. These data can't be extracted without the analysis of actual data by a n.0, pplying any of mathematical techniques. One of these mathematical techniques, called bibliometrics has been newly developed in the field of library and information science to extract the objective data for the better services through the library operations. The Beadford's Law, one important law in bibliometrics has provided rather scientific and objective basis on the more valid building of library collection within the constraints of budget. The purpose of the study is to investigate the theory of the Bradford's Law, to clarify the possible areas of its a n.0, pplication, and to discern some problems in doing so. The results of the study can be summarized as follows; (1) There is certain difference between the graphical formulation and verbal formulation of Bradford's Law. But this law is very useful for the field of library and information science, owing to the flexibility of the a n.0, pplication of the law in the field. (2) The minimal nucleus can consist of a single periodical only if j, the number of relevant papers in the most productive journals is greater than Z/2. On the other hand, if j is less than or equal to Z/2, then the minimal nucleus will consist of 2 or more periodicals. (3) It is possible to design the most compact selection of scientific periodicals covering any specified percentage P among the total periodicals by using the formulation, log n=Plog N+(1-P)logs, or Nlog N/s=P center dot N log N/s. (4) If there is need to provide all the articles needed by users the given budget, the library can purchase the proper number of journals, by using the formulation, f center dot AN=An+PN (log N/s-logn/s). (5) In the building of the library collection based on the decreasing ratio of use, the library can subscribe to the proper number of journals according to the satisfactory degree of the need, by using the formulation, f=Nu+uNlogN/S-uNlogn/s / nNlogN/s = 1+logN/m /logN/s (6) If the order of valuable journals is decided according to the frequency of being cited, the order can't always represent the value. (7) The evaluation criteria for the journals with high value, but less cited should be made a further study.

• Strategy21
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• s.41
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• pp.232-260
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• 2017

The purpose of this paper is to open a debate about what kind of deterrent strategy the ROK military should pursue in the era of NK's weapons of mass destruction and missile threats. I argue that the ROK military needs a comprehensive deterrent strategy that reflects the international security situations and trends and that builds on clear understanding of the basic concepts and how deterrence operates. The paper starts with surveying the basic knowledge of deterrence from the perspectives of both theory and practice. Then, it provides explanations on why deterrence against NK can be particularly difficult given the security environment in and around the Korean peninsula. For example, South Korea and North Korea hardly share 'common knowledge' that serves as a basic element for the operation of deterrence. Deterrence against North Korea involves complex situations in that both deterrence and compellence strategies may be relevant particularly to North Korea's WMD and missile threats. It also involves both immediate and general deterrence. Based on the discussion, I suggest several ideas that may serve as guidelines for establishing a deterrent strategy against NK. First, our threats for deterrence should be the ones that can be realized, particularly in terms of the international norms. In other words, they must be considered appropriate among other nations in the international community. Second, there should be separate plans for the different kinds of threats: one is conventional, local provocations and the other is WMD/missile related provocations. Third, we should pursue much closer cooperative relations with the U.S. military to enhance the effectiveness of immediate deterrence in the Korean peninsula. Fourth, the ROK military should aim to accomplish 'smart deterrence' maximizing the benefits of technological superiority. Fifth, the ROK military readiness and structure should be able to deny emerging North Korean military threats such as the submarine-launched ballistic missiles and intercontinental ballistic missiles. Lastly, in executing threats, we should consider that the current action influences credibility and reputation of the ROK, which in turn affect the decisions for future provocations. North Korea's WMD/missile threats may soon become critical strategic-level threats to South Korea. In retrospect, the first debate on building a missile defense system in South Korea dates back to the 1980s. Mostly the debate has centered on whether or not South Korea's system should be integrated into the U.S. missile defense system. In the meantime, North Korea has become a small nuclear power that can threaten the United States with the ballistic missiles capability. If North Korea completes the SLBM program and loads the missiles on a submarine with improved underwater operation capability, then, South Korea may have to face the reality of power politics demonstrated by Thucydides through the Athenians: "The strong do what they have the power to do, the weak accept what they have to accept."

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.45-57
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• 2020

Among the fintech businesses that are actively developing around the world, payment and settlement are the most prominent. Korea has a well-developed IT industry and a good existing card payment environment, however, its innovative movement is overwhelmingly slower than that of other countries in the fintech. In this study, we try to assess the regulations on fintech and their impacts on the startup ecosystem by comparing the cases of U.S., China, and Korea. We have found that both the United States and China have lowered barriers to entry for the newly launched fintech industry, allowing startups and IT companies to start fintech businesses at the existing financial sector. Particularly the implementation of predictable regulations in U.S., and the failure to apply the financial regulations in China, help start-up companies' growth in the fintech industry. This finding provides us with a lesson that current positive regulations in Korea should gradually change into negative regulations, and predictable regulations that strictly enforce post-management except major items rather than pre-approval. The policy implications are discussed with the perspective of start-ups in fintech industry.