• Journal of Korean Academy of Nursing
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• v.54 no.2
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• pp.193-210
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• 2024

Purpose: The objective of this study was to develop a predictive model for the sexual experiences of adolescents using the random forest method and to identify the "variable importance." Methods: The study utilized data from the 2019 to 2021 Korea Youth Risk Behavior Web-based Survey, which included 86,595 man and 80,504 woman participants. The number of independent variables stood at 44. SPSS was used to conduct Rao-Scott χ² tests and complex sample t-tests. Modeling was performed using the random forest algorithm in Python. Performance evaluation of each model included assessments of precision, recall, F1-score, receiver operating characteristics curve, and area under the curve calculations derived from the confusion matrix. Results: The prevalence of sexual experiences initially decreased during the COVID-19 pandemic, but later increased. "Variable importance" for predicting sexual experiences, ranked in the top six, included week and weekday sedentary time and internet usage time, followed by ease of cigarette purchase, age at first alcohol consumption, smoking initiation, breakfast consumption, and difficulty purchasing alcohol. Conclusion: Education and support programs for promoting adolescent sexual health, based on the top-ranking important variables, should be integrated with health behavior intervention programs addressing internet usage, smoking, and alcohol consumption. We recommend active utilization of the random forest analysis method to develop high-performance predictive models for effective disease prevention, treatment, and nursing care.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.72-77
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• 2024

Recently, the necessity for sound source localization has grown significantly across various industrial sectors. Among the sound source localization methods, sound intensimetry has the advantage of having high accuracy even with a small microphone array. However, the increase in localization error at high Helmholtz numbers have been pointed out as a limitation of this method. The study proposes a method to compensate for the bias error of the measured sound intensity vector according to the Helmholtz numbers by applying deep learning. The method makes it possible to estimate the accurate direction of arrival of the source by applying a dense layer-based deep learning model that derives compensated sound intensity vectors when inputting the sound intensity vectors measured by a tetrahedral microphone array for the Helmholtz numbers. The model is verified based on simulation data for all sound source directions with 0.1 < kd < 3.0. One can find that the deep learning-based approach expands the measurement frequency range when implementing the sound intensimetry-based sound source localization method, also one can make it applicable to various microphone array sizes.

• Journal of Korea Technology Innovation Society
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• v.11 no.4
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• pp.510-531
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• 2008

The importance of universities' knowledge to industrial innovation have widely pervaded the academia as well as policy communities. During the last three decades, a series of policy measures vitalizing the knowledge-transfer activities of academics have been implemented both in industrialized and industrializing countries. However, The concerns on the industry's influences on the academia have been raised by a group of researchers such as 'Economics of science'. Against this background, this paper addresses the issues related to the relationship between the academic research and knowledge-transfer activities. Particularly, based on the 16 years' panel data of Korean academics' patent and paper outputs, the effect of patenting activities on publishing activities is investigated. Moreover, the specific context of Korean academic system as well as general characteristics of academics are considered in the analysis and discussion. According to the results, not just the publishing and patenting outputs but their productivities have been dramatically increased during the last 16 years. The main finding is that the patenting activities have a consistent positive effect on the publishing activities of the academics in the estimations of panel models. Based on these results and the discussions, some policy recommendations for university-industry collaboration are suggested.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.340-353
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• 2020

The purpose of this study is to introduce surfing which is not a familiar leisure activity in Korea and provide understanding of surfing participants through the cross-sectional analysis on the process of forming recreational specialization from introductory levels with enthusiastic surfing participants. This study employs a qualitative approach to analyze each participant's experience on recreation specialization in detail, and in particular uses ethnographic research methods to derive participants' meaning of life and daily routines and cultural behavioral patterns changed through surfing. First, through the analysis of in-depth interview data, total 531 conceptual words were identified and the first categorization was established. Second, surfing participants mentioned that they had high expectations of surfing even before they first encountered it. Third, surfing participants noted that they experienced leisure constraints and made efforts to resolve this issue before reaching the recreation specialization process. Fourth, surfing participants were found to go through a recreation specialization process. Fifth, surfing participants were found to undergo life changes. They worked hard in their everyday life through physical training, improvement of surfing skills, and analysis of their own videos to be better at surfing.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.118-122
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• 2003

본 논문은 무선통신 환경에서 다양한 위치정보의 응용서비스인 위치기반서비스의 공통적인 기능을 가지는 지오코더 서비스를 설계하는 것이다. 위치기반서비스는 망이나 GPS 등의 측위기술을 이용하여 휴대 단말 등 사용자의 위치정보를 제공하는 것으로 최근 부가가치가 기대되는 서비스이다. 지오코더 서비스는 주소 등의 요청에 대해 X, Y, Z 등으로 표현되는 지리적 위치정보를 제공하는 서비스와 역으로 지리적 위치정보를 포함하는 요청에 대해 주소 등을 포함한 정규화 된 정보를 제공하는 역지오코더 서비스로 정의할 수 있다. 국내의 많은 웹 기반의 GIS 서비스들이 지형지물 등에 의해 지리적인 위치를 탐색하는 지오코딩 기능이 구현되어 있으나, 지리 정보에 대한 각각 서로 다른 인터페이스들이 사용되고 있어, 확장된 활용성에 한계를 가지고 있다. 특히, 무선통신 환경의 발전에 따른 효율적인 지리적 위치정보의 활용을 통한 다양한 위치기반서비스의 개발 및 활성화를 위하여 국제동향을 고려한 정규화 된 지오코더 서비스의 개발이 요구된다. 본 논문에서는 지리적 위치정보를 포함하고 있는 지오코더 서비스를 위하여 기술규격 범위와 요구기능 정의, 서비스를 위한 데이터의 정규화 및 인터페이스를 설계하여, 국내 무선통신 환경에서 다양한 위치기반서비스의 활용성을 높이기 위한 서비스 시스템 방안을 마련하고자 한다. 또한, 주소 정의에 있어서 국내 주소체계를 충분히 분석하여 구축하였다. 이는 본 연구자가 LBS 표준화 포럼을 통하여 작성 중인 '지오코더서비스 인터페이스 기술규격'을 수용한 것이다.적으로 분석하고, 지형정보의 체계적 관리를 위해 가장 필요한 해안습지 지형분류도를 작성하기 위해 가장 기초적인 단계인 해안습지 지형분류체계에 대한 국내외의 연구성과를 비교하여 시안을 작성 표준화를 위한 첫 단계 시도를 소개하였다.분석 결과는 문장, 그림 및 도표, 장 끝의 질문, 학생의 학습 활동 수 등이 $0.4{\sim}1.5$ 사이의 값으로 학생 참여를 적절히 유도하는 발견 지향적 인 것으로 조사되었다. 그러나 장의 요약은 본문 내용을 반복하는 내용으로 구성되었다. 이와 같이 공통과학 과목은 새로운 현대 사회에 부응하는 교과 목표와 체계를 지향하고 있지만 아직도 통합과학으로서의 내용과 체계를 완전히 갖추고 있지 못할 뿐만 아니라 현재 사용되고 있는 7종의 교과서가 교육 목표를 충분히 반영하지 못하고 있다. 따라서 교사의 역할이 더욱더 중요하게 되었다.괴리가 작아진다. 이 결과에 따르면 위탁증거금의 징수는 그 제도의 취지에 부합되고 있다. 다만 제도운용상의 이유이거나 혹은 우리나라 주식시장의 투자자들이 비합리적인 투자형태를 보임에 따라 그 정책적 효과는 때로 역기능적인 결과로 초래하였다. 그럼에도 불구하고 이 연구결과를 통하여 최소한 주식시장(株式市場)에서 위탁증거금제도는 그 제도적 의의가 여전히 있다는 사실이 확인되었다. 또한 우리나라 주식시장에서 통상 과열투기 행위가 빈번히 일어나 주식시장을 교란시킴으로써 건전한 투자풍토조성에 저해된다는 저간의 우려가 매우 커왔으나 표본 기간동안에 대하여 실증분석을 한 결과 주식시장 전체적으로 볼 때 주가변

• Journal of Information Management
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• v.36 no.3
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• pp.183-193
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• 2005

Korean Academy of Medical Sciences began developing Korean Medical Citaton Index(KoMCI) database in 2002, and has announced the impact factors of Korean medical journals published since 2000. In July 2005, Korea Research Foundation also announced the KCI impact factor of journals covering all subject areas for the 2003 and 2004. We compared the impact factor(IF), impact factor excluding self-citation(ZIF), and self-citation impact factor(SIF) of KoMCI 2004 and KCI 2004 in order to disclose why there is such a great difference in the values of impact factors between two databases. Out of 72 medical journals in both database, 59 journals were compared after excluding the missing data in KCI. Mean IF of KoMCI 2004 was 0.2 and that of KCI 2004 was 0.03(p=0.0000). Mean ZIF of KoMCI was 0.06 and that of KCI was 0.01(p=0.000). Mean SIF of KoMCI was 0.139 and that of KCI was 0.02(p=0.0000). We presumed that the major difference in the impact factor values was originated from the fact that KCI does not control the authority of journal names cited in the references. We strongly recommend that it is necessary to control the authority especially if Korea Research Foundation wants to ensure the validity and reliability of KCI data in the evaluation of korean journals.

• Korean Journal of Remote Sensing
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• v.34 no.6_2
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• pp.1203-1213
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• 2018

In Arctic and Antarctic ocean, remote sensing is the most effective observation for environmental changes due to the inaccessibility of the regions. Even though satellite, UAV (Unmanned Aerial Vehical) are well known remote sensing platforms, and research vessel also used for automatic measurement on the regions, varied environment of Polar regions require time series and wide coverage of data. Especially, in high latitude, apply an optical satellite remote sensing is not easy due to low sun altitude. In this paper, we introduce an operation of hyper-spectrometer (HyperSAS/Satlantic inc.) which is mounted on Ice Breaker Research Vessel ARAON of Korea Polar Research Institute since 2010, to acquire an above water reflectance atomatically through every research cruise on Arctic and Antarctic ocean and transit both regions. In addition to, auxiliary data for the remotely acquired data, in situ water sampling were also obtained. The above water reflectance and in situ water sampling data are continuously acquired since 2010 will contribute to improve an Ocean Color algorithm in the high latitude and help to understand ocean reflectances over from high latitude through low latitude. Preliminary result from above water reflectance showed characteristics of Arctic ocean and Antarctic Ocean and used to develop algorithms for estimating various ocean factors such as chlorophyll and suspended sediment.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.411-422
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• 2021

The purpose of this study was to examine the relationship between major satisfaction and university life adaptation according to the amount of physical activity for university students. This study implement survey to the 201 university students. Descriptive statistics, reliability analysis, one-way ANOVA and pearson's correlation analysis were conducted for data analyses. The results are as follows. First, university students' major satisfaction with the amount of physical activity is statistically significantly higher than that of low-intensity physical activity groups (p<.05). Second, university life adaptation according to the amount of physical activity was found to be statistically significantly higher in high-intensity physical activity groups than in medium-intensity physical activity groups and low-intensity physical activity groups (p<.05). Lastly, according to the relationship between physical activity, major satisfaction, and university life adaptation of university students, male students have a static correlation between physical activity, major satisfaction (general satisfaction), and university life adaptation (personal emotion adaptation) and female students have a static correlation between physical activity and university life adaptation(social adaptation) (p<.05). This study confirmed that the amount of physical activity of university students is related to their major satisfaction and adaptation to university life. Based on this conclusion, it is expected that university students will be able to manage their university life through physical activities.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.794-807
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• 2022

Although registration of dogs is mandatory according to the revision of the Animal Protection Act, the registration rate is low due to the inconvenience of the current registration method. In this paper, a performance improvement study was conducted on the dog face recognition technology, which is being reviewed as a new registration method. Through deep learning learning, an embedding vector for facial recognition of a dog was created and a method for identifying each dog individual was experimented. We built a dog image dataset for deep learning learning and experimented with InceptionNet and ResNet-50 as backbone networks. It was learned by the triplet loss method, and the experiments were divided into face verification and face recognition. In the ResNet-50-based model, it was possible to obtain the best facial verification performance of 93.46%, and in the face recognition test, the highest performance of 91.44% was obtained in rank-5, respectively. The experimental methods and results presented in this paper can be used in various fields, such as checking whether a dog is registered or not, and checking an object at a dog access facility.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.1
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• pp.1-10
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• 2022

In this study, the two horizontal shroud tidal current energy converter, which can generate power even under low flow speed conditions, was developed. In order to determine the shape of the shroud system, a three-dimensional numerical simulation test was conducted, and a 1/6 scale down model was made to perform a hydraulic model experiment. The hydraulic model experiment was performed under four flow conditions, and the flow speed, torque, and RPM were measured for each experimental case. As a result of the numerical simulation test, it was found that the flow speeds passing through the nozzle were increased by about 2~3 times in the cylinder, and when the extension ratio was 2:1, the highest flow speed was shown. In addition, it was found that the flow speeds increased 2.8 times when the diameter ratio between the nozzle and the cylinder was 1.5:1. Meanwhile, as a result of the hydraulic model experiment, it was found that when the tip speed ratio was between 1.75 and 2, the power coefficient was 0.32 to 0.34.