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Study on the defenses behavior mechanism of Vespa hornets to the artificial disturbances
Dongwon Kim,Chuleui Jung 한국응용곤충학회 2017 한국응용곤충학회 학술대회논문집 Vol.2017 No.04
Recently we are facing increased frequency of the vespa encounters not only in the natural forested area but also in the residential area. These could be partly from the increased population sizes of diverse vespa species as well as the expansion of their nest habitats from mountainous environments to the human residences, resulting occasional casualty or sting damages. In terms of the risk management, we studied hornet attack and defense behaviors relative to the visual or physical disturbance. Four species of vespa showed strongest aggressiveness to the black colored target with high rate of bumping and stinging followed by red color. In most case, vespa showed behavioral change to the high alerts and hover-flying surveillance out of the nest entrance when people approached ap. 10 m close to the nest. When the nest was disturbed by the stick beating, then swarm of defensive force moved out and begin to showed the defensive behavior including stinging or propelling poison. The defense boundary was related to the nest colony size with larger defense line for larger colony. But it was between 15 to 25m from the nest location.
The Ferroelectricity and Electrical Properties of P(VDF-TrFE) Copolymer Film
Dong-Won Kim,Byung-Eun Park,Gwang-Geun Lee 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.2I
Poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE)) copolymer thin films with a molar ratio of 75/25 have been studied to investigate their ferroelectricity. P(VDF-TrFE) solutions of 3, 7 and 10 wt% were fabricated on Si(100) substrates by using a spin-coating method. In order to achieve crystallization, we annealed the deposited films at 150 C for one and half hours without any addional treatments, such as a heat-treatment, poling, or mechanical drawing. The thicknesses of the deposited films were 60, 170 and 400 nm for the 3, 7 and 10 wt% solutions, respectively. Hysteretic characteristics were observed in the capacitance-voltage (C-V) curves for Au/P(VDFTrFE)/ Si diodes and may be considered to be due to the ferroelectric nature of the P(VDF-TrFE) films. The memory window width was measured at a low voltage below 1 V for a film coated with a 3 wt% solution. The memory window widths in this metal-ferroelectric-semiconductor (MFS) fabricated with 3, 7 and 10 wt% P(VDF-TrFE) solutions were about 1.2, 2.7 and 3.6 V for a bias sweep from .5 V to 5 V, respectively.
Dong-Won Kim,Gwang-Geun Lee,Joo-Nam Kim,Hyung-Jin Park,Ho-Seung Jeon,Byung-Eun Park 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7
In this work, in order to investigate the possibility for application to one transistor-type (1T-type) ferroelectric random access memory (FeRAMs), we fabricated metal-ferroelectricsemiconductor (MFS) diodes with polyvinylidene fluoridetrifluoroethylene (PVDF-TrFE) (51/49) thin films. The thin films with 50-㎚-, 170-㎚-, and 320-㎚-thickness (sample A, Band C) were prepared on the silicon substrate by using spin-coating method. The grain size of the PVDF-TrFE increased as the filmthickness increased. Typical ferroelectric hysteresis loops were obtained from the capacitance-voltage (C-V) curves, and that might be considered to be due to the ferroelectric nature of PVDFTrFE films. The values of memory window width for sample A, B and C were about 1.5, 3.7 and 4.7 V for a bias sweeping from -5 V to 5 V, respectively. The values of the leakage current density at a sweeping range of ±5 V were about 2.7×10?? A/㎠, 1.1×10?? A/㎠ and 5.6×10?? A/㎠ for 50-㎚-, 170-㎚-, and 320-㎚thick films, respectively. These results are useful and promising for realizing 1T-type FeRAMs operating at a low voltage.
An Energy Efficient MAC Protocol Providing Guaranteed Service for Wireless Sensor Network
( Dong Won Kim ),( Tae-geon Park ) 한국인터넷정보학회 2011 KSII Transactions on Internet and Information Syst Vol.5 No.1
In this paper, we propose an Energy Efficient Media Access Control (EE-MAC) protocol for wireless sensor networks. The proposed scheme is designed to save power consumption and guarantee quality-of-service for real-time traffic. EE-MAC uses the superframe structure which is bounded by the transmission of a beacon frame and can have an active and an inactive portion. The active period is divided into the contention free period (CFP) for real-time traffic transmission and the contention access period (CAP) for non-real-time traffic transmission. We propose the exclusively allocated backoff scheme which assigns a unique backoff time value to each real-time node based on bandwidth allocation and admission control. This scheme can avoid collision between real-time nodes by controlling distributed fashion and take effect a statistical time division multiple access. We also propose the algorithm to change the duty cycle adaptively according to channel utilization of media depending on network traffic load. This algorithm can prolong network lifetime by reducing the amount of energy wasted on idle listening.
Computing Exact Skyline Probabilities for Uncertain Databases
Dongwon Kim,Hyeonseung Im,Sungwoo Park IEEE 2012 IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERIN Vol.24 No.12
<P>With the rapid increase in the amount of uncertain data available, probabilistic skyline computation on uncertain databases has become an important research topic. Previous work on probabilistic skyline computation, however, only identifies those objects whose skyline probabilities are higher than a given threshold, or is useful only for 2D data sets. In this paper, we develop a probabilistic skyline algorithm called PSkyline which computes exact skyline probabilities of all objects in a given uncertain data set. PSkyline aims to identify blocks of instances with skyline probability zero, and more importantly, to find incomparable groups of instances and dispense with unnecessary dominance tests altogether. To increase the chance of finding such blocks and groups of instances, PSkyline uses a new in-memory tree structure called Z-tree. We also develop an online probabilistic skyline algorithm called O-PSkyline for uncertain data streams and a top-k probabilistic skyline algorithm called K-PSkyline to find top-k objects with the highest skyline probabilities. Experimental results show that all the proposed algorithms scale well to large and high-dimensional uncertain databases.</P>
Dong-Won Kim 한국방사성폐기물학회 2013 방사성폐기물학회지 Vol.11 No.3
2011년 3월 발생한 일본의 후쿠시마 원전 사고는 원전의 안전성 문제를 넘어 경제성까지 논란을 불러일으키 고 있으며, 이러한 문제는 원전 확대에 대한 비판적 시각을 전 세계적으로 확대시키고 있다. 따라서 원전이 안 전성을 충분히 유지하면서도 타 전원에 비해 경제성이 있다는 것을 입증한다면 현재는 물론 지속가능한 전원 으로서의 원전의 역할을 기대할 수 있을 것이다. 후쿠시마 원전사고 이후 국민들이 실제로 느끼는 ‘사회적 안전성’ 정도를 알아보기 위해 안전성 대신 일반국 민의 수용성을 지표로 삼아 안전에 대한 비용을 얼마나 지불할 수 있느냐를 알아보기 위해 비용편익분석의 하 나인 조건부가치측정법(CVM: contingent valuation method)을 이용하였다. 경제성과 안전성의 trade-off값을 설문조사를 통해 알아본 결과 발전원가 4.75 원/kWh 인상효과를 가져왔다. 이를 현재 원전발전단가 39.11 원/kWh에 반영하면 43.86 원/kWh으로 석탄화력 발전원가 67 원/kWh과 비교해 여전히 경쟁력이 있는 것으로 나타났다. 이러한 결과는 2013년 말 수립예정인 제2차 에너지기본계획[1] 등에 기초자료로 중요한 정책적 시 사점을 가져다 줄 것이다.
( Dong Won Kim ),( Seong Beom Choi ),( Woo Jin Jung ) 국제태권도학회 2017 International Symposium for Taekwondo Studies Vol.2017 No.-
Purpose: The purpose of this study was to develop Taekwondo importance of managing brand personality, an important intangible asset in a competitive market, by examining the impacts of brand personality to enhance brand loyalty on brand identification, brand effect, and brand loyalty. Methods: To accomplish the purpose of this study, the research subjects were 156 male and female Chinese Taekwondo masters who participated in the 2014 Chinese Taekwondo Seminar located in Sichuan Province, China. Using a questionnaire, frequency analysis, individual peculiarities, t-test, one-way ANOVA, Scheffe’'s multiple comparison of verification, correlation analysis, and multiple liner regression tests were conducted and analyzed. All significance levels were configured at p < 0.05 for data analysis. Results: The results of this study are summarized as follows. First, there was a significant difference in brand personality and brand identification, brand effect, and brand loyalty. Second, there was a significant correlation between brand personality on brand identification, brand effect, and brand loyalty in Chinese Taekwondo services. Conclusions: These findings indicate that Taekwondo service providers manage brand image and brand personality in order to increase brand loyalty to establish Taekwondo as a brand. Experience and exposure to a brand is a major factor for building long-term relationships between consumers and the brand. Further brand identification, which in this case applies to Taekwondo trainees, would increase brand loyalty, intention to continue Taekwondo training, and suggest training to potential trainees.