• Journal of The Korean Astronomical Society
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• v.41 no.1
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• pp.7-15
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• 2008

We carried out a set of simulations to reproduce the performance of wide-field NEO surveys based on the revised population model of Near Earth Objects (NEOs) constructed by Morbidelli (2006). This is the first time where the new model is carefully compared with discovery statistics, and with the exception of population model, the simulation is identical to the procedure described in Moon et al. (2008). Our simulations show rather large discrepancy between the number of NEO discoveries made by the actual and the simulated surveys. First of all, unlike Bottke et al. (2002)'s, Morbidelli (2006)'s population model overestimates the number of NEOs. However, the latter reproduces orbit distributions of the actual population better. Our analysis suggests that both models significantly underestimate Amors, while overestimating the number of Apollos. Our simulation result implies that substantial modifications of both models are needed for more accurate reproduction of survey observations. We also identify Hungaria region (HU) to be one of the most convincing candidates that supply a large fraction of asteroids to the inner Solar System.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1241-1251
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• 2014

Based on the 4 principal research-performance criteria in 28 national universities in Korea, both cluster analysis and multidimensional scaling are performed in this paper. We can classify and/or specialize the initially unknown groups into a group of relatively homogeneous universities and then create new groupings without any preconceived notion of what clusters may arise. Furthermore, the level of similarity of individual universities can be visualized on the multidimensional space so that each university is then assigned coordinates in each of the 2 dimensions. Both types and characteristics of each university can be relatively evaluated and be practically exploited for the policy of the university authority through these results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1616-1623
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• 1999

This paper describes error resilient coding scheme is added in WLL system and its application for robust low-bit rate still image transmission over power controlled W-CDA system Rayleigh fading channels. The baseline JPEG compressing methods are uses in image coding over wireless channel. The channel uses Reed-Solomon(RS) outer codes concatenated with convolutional inner codes, and truncated type I hybrid ARQ protocol based on the selective repeat strategy and the RS error detection capability. Simulation results are proved for the statistics of the frame-error bursts of the proposed system in comparison with conventional WLL system. it gains the 2 dB of the Eb/No in same BER.

• Journal of Korean Institute of Fire Investigation
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• v.3 no.1
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• pp.16-32
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• 2003

Today, fires are becoming so catastrophic and complicated due to the industrialization and diversification of energy sources that it is getting more difficult to define the survey items in order to find out the causes and processes of the fire. As an organization of prevention, vigilance and putting out of the fire, Fire Fighting authorities are ultimately pursuing the system of fire fighting administration to protect human lives and their properties through establishment and performance of fire prevention policy based on the fire-related statistics they have gathered and prevention of future fires of the kind which can promote the safety of structural space. Thus, to facilitate the fire detection, it can be said that good understanding of the tasks of both investigation and putting out of the fire as being two axes has the greatest significance. For this study, textbooks from the organization of fire fighting and police, which are designed for the literature study on the investigation and putting out of fire, are used and for the demonstrative study, the conclusions have been reached by the analyses of the 64 questionnaires of three parts which were divided by fire investigation and fighting for three hundred and six governmental employees engaging in the above fields.

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.13-28
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• 2002

Higher efficiency and effectiveness of Research & Development phases can be attained using advanced statistical methodologies. In this work statistical methodologies are combined with a deterministic approach to engineering design. In order to show the potentiality of such integration, a simple but effective example is presented. It concerns the problem of optimising the performances of a paper helicopter. The design of this simple device is not new in quality engineering literature and has been mainly used for educational purposes. Taking full advantage of fundamental engineering knowledge, an aerodynamic model is originally formulated in order to describe the flight of the helicopter. Screening experiments were necessary to get first estimates of model parameters. Subsequently, deterministic evaluations based on this model were necessary to set up further experimental phases needed to search (or a better design. Thanks to this integration of statistical and deterministic phases, a significant performance improvement is obtained. Moreover, the engineering knowledge かms out to be developed since an explanation of the “why” of better performances, although approximate, is achieved. The final design solution is robust in a broader sense, being both validated by experimental evidence and closely examined by engineering knowledge.

• ETRI Journal
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• v.41 no.2
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• pp.197-206
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• 2019

Software-defined networking (SDN) is a modern approach for current computer and data networks. The increase in the number of business websites has resulted in an exponential growth in web traffic. To cope with the increased demands, multiple web servers with a front-end load balancer are widely used by organizations and businesses as a viable solution to improve the performance. In this paper, we propose a load-balancing mechanism for SDN. Our approach allocates web requests to each server according to its response time and the traffic volume of the corresponding switch port. The centralized SDN controller periodically collects this information to maintain an up-to-date view of the load distribution among the servers, and incoming user requests are redirected to the most appropriate server. The simulation results confirm the superiority of our approach compared to several other techniques. Compared to LBBSRT, round robin, and random selection methods, our mechanism improves the average response time by 19.58%, 33.94%, and 57.41%, respectively. Furthermore, the average improvement of throughput in comparison with these algorithms is 16.52%, 29.72%, and 58.27%, respectively.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.393-396
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• 2022

본 연구는 국방과학기술 분야의 특허 및 논문 실적을 이용하여 통계기반 기계학습 모델 4 종을 학습하고, 실제 분석 대상기관의 데이터 입력결과를 분석하여 실용성에 대한 한계점 분석을 목적으로 한다. 기존 연구에서는 특허분류코드를 기준으로 분류하여 특수 목적으로 활용하거나 세부 연구 범위 내 연구 주제탐색 및 특징연구 등 미시적인 관점에서의 상세연구 활용 목적인 반면, 본 연구는 거시적인 관점에서 연구의 전체적인 흐름과 경향성 파악을 목적으로 한다. 이에 ICT 기술 138 종의 특허 및 논문 30,965 건과 국방과학기술 192 종의 특허 및 논문 23,406 건을 학습데이터로 각 모델을 학습하였다. 비교한 통계기반 학습모델은 Support Vector Machines, Decision Tree, Naive Bayes, XGBoost 모델이다. 학습데이터에 대한 학습검증 단계에서는 최대 99.4%의 성능을 보였다. 다만, 실제 분석대상기관의 특허 및 논문 12,824 건으로 입력분석한 결과, 모델별 편향성 문제, 데이터 전처리 이슈, 다중클래스 및 다중레이블 문제를 확인, 도출한 문제에 대한 해결방안을 제시하고 추가 연구의 방향성을 제시한다.

• Journal of information and communication convergence engineering
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• v.21 no.4
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• pp.322-328
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• 2023

The number of senior citizens with large bowel obstruction is steadily growing in Korea. Plain radiography was used to examine the severity and treatment of this phenomenon. To avoid examiner subjectivity in radiography readings, we propose an automatic segmentation method to identify fluid-filled areas indicative of large bowel obstruction. Our proposed method applies the Hough transform to locate suspicious areas successfully and applies the possibilistic fuzzy c-means unsupervised learning algorithm to form the target area in a noisy environment. In an experiment with 104 real-world large-bowel obstruction radiographs, the proposed method successfully identified all suspicious areas in 73 of 104 input images and partially identified the target area in another 21 images. Additionally, the proposed method shows a true-positive rate of over 91% and false-positive rate of less than 3% for pixel-level area formation. These performance evaluation statistics are significantly better than those of the possibilistic c-means and fuzzy c-means-based strategies; thus, this hybrid strategy of automatic segmentation of large bowel suspicious areas is successful and might be feasible for real-world use.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.213-228
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• 2024

Purpose: The purpose of this study was to investigate the relationship between emotional intelligence, nursing professionalism, and resilience of nursing students and to identify the factors affecting resilience of nursing students. Methods: Data were collected from 205 nursing students in the 1st, 2nd, and 3rd grades of nursing colleges located in J province, and a survey was conducted from November 20th to November 30th, 2023. The collected data were analyzed through descriptive statistics, t-test, one-way ANOVA, Scheffe test, Pearson's correlation coefficient, and stepwise multiple regression analysis using SPSS/WIN 29.0 program. Result: The emotional intelligence of the subjects showed a significant positive correlation with nursing professionalism(r=.56 p<.001) and resilience(r=.75, p<.001), and nursing professionalism showed a significant positive correlation with resilience(r=.55, p<.001). The major factors influencing the resilience of nursing students were emotional intelligence, nursing professionalism, academic performance, and personality in order, and their explanatory power was 62% (F=83.05 p<.001). Conclusion: Based on the results of this study, it is necessary to develop an educational program that improves emotional intelligence and nursing professionalism in order to strengthen the resilience of nursing students.

• Journal of Korean Critical Care Nursing
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• v.17 no.1
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• pp.17-29
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• 2024

Purpose : This study sought to investigate novice nurses' communication education needs in the intensive care unit (ICU) using Importance-Performance Analysis (IPA) and Borich's need assessment model. This study identified communication challenges in clinical settings to develop a simulation program that enhances communication competencies based on educational requirements. Methods : A descriptive research design and a self-report questionnaire were used. The latter was developed and administered to 121 novice nurses with less than one year of experience in the ICU at various university hospitals in Korea. Data were collected via the online open chatroom from June 24th to July 28th, 2023. The communication education needs were identified using descriptive statistics, t-tests, IPA, and Borich's needs assessment model. Text analysis was used to categorize the participants' communication experience. Results : The results revealed that "communication with physicians," "communication with patients," and "communication with nurse on another shift" domains contained the most substantial educational needs for novice nurses working in the intensive care units. Conclusion : The results provide fundamental data for developing and enhancing customized communication education programs for novice ICU nurses. This valuable information could help ICU nurses and educators improve new nurses' communication skills, which would ultimately contribute to the advancement of nursing education and clinical practice.