• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2343-2349
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• 1999

The hyper-geometric distribution software reliability growth model (HGDM) was recently developed and successfully applied to real data sets. The HGDM considers the sensitivity factor as a parameter to be estimated. In order to reflect the random behavior of the test-and-debug process, this paper generalizes the HGDM by assuming that the sensitivity factor is a binomial random variable. Such a generalization enables us to easily understand the statistical characteristics of the HGDM. It is shown that the least squares method produces the identical results for both the HGDM and the generalized HGDM. Methods for computing the maximum likelihood estimates and predicting the future outcomes are also presented.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.57-61
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• 2002

최근 들어 인터넷과 관련한 정보통신기술의 발전은 모든 산업환경을 변화시키고 있고, 조선 산업에서도 설계 생산성을 향상시키기 위해서 새로운 설계 패러다임을 선박설계 과정에 적용하고 있다. 현재 차도선을 설계하는 설계사무소의 경우 전문 설계인력이 부족함과 동시에 설계 과정은 동일한 작업이 반복적으로 수작업을 통해 이루어지고 있는 상태이다. 이러한 수작업의 반복은 설계 과장에서 에러를 발생시키고 각 설계 단계별로 발생하는 설계 데이터의 에러로 인해 설계생산성을 저하시키는 요인으로 작용될 수 있다. 따라서 본 시스템 개발은 초기설계 과정을 전산프로그램화 하여 초기설계 단계에서의 설계정보 데이터의 정확성을 높여 설계생산성을 향상시키고 또한 이 프로그램을 인터넷 기반으로 제공하여 분산된 환경에서도 다른 설계 전문가들이 함께 참여 할 수 있게 해 설계 정보를 동시에 공유하여 원격지에서도 설계자가 원하는 자료를 검색할 수 있도록 하는데 목적이 있다. 본 연구는 인터넷 기반을 통한 차도선의 초기설계 프로그램의 핵심을 이루는 인터넷 기반 구현 방법에 대해 소개하고 특히 인터넷 환경에서 차도선의 초기설계 프로그램을 통해 설계정보의 교환 및 공유를 원활하게 구현하는 시스템을 개발하는데 있다.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.11-17
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• 2021

In this paper, we demonstrate a performance boost by parallelizing a purely functional bisimulation algorithm on a multicore processor machine. The key idea of this parallelization is exploiting the referential transparency of purely functional programs to minimize refactoring of the original implementation without any parallel constructs. Both original and parallel implementations are written in Haskell, a purely functional programming language. The change from the original program to the parallel program is minuscule, maintaining almost original structure of the program. Through benchmark, we show that the proposed parallelization doubles the performance of the bisimulation test compared to the original non-parallel implementation. We also shaw that similar performance boost is also possible for a memoized version of the bisimulation implementation.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.187-189
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• 2017

본 논문에서는 승용자동차에 대한 소화기 비치 필요성 및 소화기의 효용성 및 적정성에 대해 평가하고자 한다. 이를 위해 소방청 국가화재정보센터에 입력된 차량화재를 분석하였으며, 국외 자동차용 소화기 비치기준을 조사하였다. 또한, 자동차를 대상으로 한 시뮬레이션 선행연구 결과를 분석하여 다른 차종에 비해 승용자동차의 위험도가 가장 높다. 한편, 기존의 시뮬레이션 연구결과를 분석해보면 소화기를 이용한 초기진화가 가능한 황금시간은 실내화재 시 2분, 엔진룸화재 시 약 7분 정도임을 알 수 있다. 이는 승용자동차 화재 시 소화기를 이용한 초기소화가 절실하다고 할 수 있다. 따라서 승용자동차 화재로부터 국민의 안전과 재산을 보호하고 국내 자동차 안전환경 및 자동차 안전기준을 국제기준에 맞춰 국제 경쟁력을 확보하기 위해서는 승용자동차에 소화기 비치를 의무화할 필요성이 있다.

• Korean small business review
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• v.42 no.1
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• pp.135-165
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• 2020

This study aimed to examine relationships between founders' entrepreneurial leadership, team learning behavior, team boundary spanning, and perceived performance in early-stage startups. The following results were recorded: (i) the indirect effects of entrepreneurial leadership on perceived performance via team learning behavior were statistically significant (β=.309, p<.05). (ii) relationships between team learning behavior and perceived performance were strengthened by team boundary spanning behavior (β=.259, p<.05). In this study, three practical implications are provided as follows: (i) startups need to seek team learning readiness and external learning stimulus to facilitate generative and transformative team learning; (ii) accelerators need to develop an entrepreneurial leadership program for founders; and (iii) startups need to explore external information by interacting with investors, R&D institutions, and other startups to strengthen the impact of team learning behavior on performance. Furthermore, two directions for future research are suggested as follows: (i) future researchers need to test causal relationships between entrepreneurial leadership and team learning behavior based on a newly designed time-series measurement plan; (ii) the actual effects of entrepreneurial leadership, team learning behavior and team boundary spanning on financial performance need to be tested two or three years later when the financial performance of early-stage startups usually becomes evident.

• Korean Journal of Culture and Social Issue
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• v.27 no.3
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• pp.305-323
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• 2021

This study examined the effects of self-concealment and satisfication among the basic psychological needs on the commitment to opposite-sex romantic relationships in early adulthood. The study examined the mediating effects of basic psychological needs, autonomy, competence, and relatedness, in the relationship between self-concealment and the commitment to opposite-sex romantic relationships. For this purpose, a self-report survey was conducted on 197 adults aged 20 to 29 who are currently in opposite-sex romantic relationships, and the collected data were analyzed using SPSS 26.0 and PROCESS MACRO v3.5. The main results of this study are as follows. First, gender, age, and duration of dating period among the subject's demo-social variables significantly impacted the commitment to opposite-sex romantic relationships. Second, satisfying relatedness among the basic psychological needs had the largest influence on the commitment to opposite-sex romantic relationships, and self-concealment negatively affected the commitment to opposite-sex romantic relationships. Third, relatedness from the basic psychological needs had a significant mediating effect between self-concealment and the commitment to romantic relationships. It can be seen that it is crucial to lower self-concealment and to satisfy relatedness among the basic psychological needs in order to promote commitment to romantic relationships in early adulthood. This study is meaningful in that it tried to reveal the influence of individual psychological factors on the commitment to the romantic relationship, and it is significant that it proposed a basis for intervention to promote the commitment to opposite-sex romantic relationships in early adulthood.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.863-870
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• 2023

Ship capsize accidents are common in coastal waters, particularly involving small fishing boats. To prevent there overturing accidents in small fishing boats, their stabilities must be assessed at the initial design step. However, the available information during the initial design step is limited, posing challenges in performing a reliable stability evaluation. Therefore, this study presents a plan to estimate the transverse metacenter (GM) of small fishing boats using parameters such as KM, KG, and TRIM that can be determined at the initial design step. Stability was evaluated by comparing GM with the minimum transverse metacenter (GMmin) specified in the standard safety evaluation criteria for fishing boats. To calculate the required trim value for hydrostatic characteristics using K-SHIP, a stability assessment program provided by the Korea Maritime Safety and Transportation Corporation, the initial trim state is estimated based on the ship lines using the commercial CFD program STAR-CCM+. GM is then calculated by assessing the hydrostatic characteristics in relation to the boat lines using K-SHIP. Furthermore, the stability of the fully loaded state is compared by subtrcating GM from GMmin. One constructed ship is designated as the standard ship, and the stability assessment method proposed in this study is applied to evaluate stability and validate its effectiveness. Consequently, the representative line of a 4.99-ton fishing boat and nine modular lines models derived from it were evaluated, ultimately identifying a relatively superior stability.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.851-856
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• 2016

Despite all the recent advances in biodegradable material-based microneedles, the bending and failure (especially buckling) of a biodegradable microneedle during skin tissue insertion remains a major technical hurdle for its large-scale commercialization. A reduction in skin tissue puncture force during microneedle insertion remains an essential issue in successfully developing a biodegradable microneedle. Here, we consider uniaxial and equibiaxial prestrains applied to a skin tissue as mechanophysical stimuli that can reduce the skin tissue puncture force, and investigate the effect of prestrain on the changes in skin tissue puncture force. For a porcine skin tissue similar to that of humans, the skin tissue puncture force of a flat-end microneedle is measured with a z-axis stage equipped with a load cell, which provides a force-time curve during microneedle insertion. The findings of this study lead to a quantitative characterization of the relationship between prestrain and the skin tissue puncture force.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.621-629
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• 1992

This study is concerned with an application of the Boundary Element Method to 2-dimensional elastoplastic stress analysis on the material nonlinearities. The boundary integral formulation adopted an initial stress equation in the inelastic term. In order to determine the initial stress increment, the increment of initial elastic strain energy due to elastic increment in stressstrain curve was used as the convergence criterion during iterative process. For the validity of this procedure, the results of B.E.M. with constant elements and NISA with linear elements where compared on the thin plate with 2 edge v-notches under static tension and the thick cylinder under internal pressure. And this paper compared the results of using unmedical integral with the results of using semi-analytical integral on the plastic domain integral.

• Journal of KIISE:Software and Applications
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• v.37 no.7
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• pp.536-547
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• 2010

Relative importance and complexity of recent software is getting increased because the software is needed to provide considerable amount of functions and high performance. Therefore, developing reliable software is importantly issued. In order to develop reliable software, it is necessary to manage software reliability at the early phases, but most reliability estimation models are used at system or operational test phases. In order to develop highly reliable software, it is necessary to manage software reliability at the early test phases based on characteristic of the phases that is developers and testers are not separated and developers perform test and debug activities together. Therefore, a new reliability estimation model considering test and debug time together is necessarily needed. In this paper, we propose a new reliability estimation model to manage reliability of individual units from the early test phases and in order to show how to fit the model to actual data and usefulness, we collected industrial data and used it for the experiment.