• Title/Summary/Keyword: Defence Data

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A method for selecting the evaluation index of defence R&D project by AHP (계층분석법에 의한 국방연구개발 평가지표 선정에 관한 연구)

  • Park, Seong;Hong, Yeon-Woong;Na, Joong-Kyung
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.5
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    • pp.961-970
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    • 2012
  • To evaluate companies that participated in the defense R&D project, 27 variables are chosen through literature survey, feature analysis of defense R&D and interviews with military experts. 17 variables are selected after factor analysis which is applied to reduce the number of variables and to detect structure in the relationships among variables, that is to classify variables using Likert-type scales. And then 17 variables are prioritized by AHP (analytic hierarchy process) method. It is shown that communication skill & cooperation strategy, level of technology, possession of needs technology have high priorities. However, protection plan of technology leakage, expertise of subcontractors, software development plan have low priorities.

Efficiency Analysis Solar Cell of the Dynamic Boat's by SPA (SPA에 의한 동적인 보트의 태양전지 효율 분석)

  • Han, Jong-Ho;Lee, Jang-Myung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1529-1536
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    • 2011
  • Recently, worldwide government policy is pursuing saving energy and preservation. add to this, the solar cells are getting the spotlight nonpolluting energy source, using a variety of products for solar cell. in this paper, we'll make solar tracking system for suitable of dynamic boat. we knew that general boats are using fixed solar cell, it's first time to use tracking system of solar cells for boats so it is hard to application. To solve this problem in this paper we use to a magnetic compass and GPS for suitable solar tracking system of dynamic movement and to analyze fixed and tracking solar system. frist. solar tracking device is designed two-axis control system. one-axis control system is taken a magnetic compass for making efficiency defence solar tracking sensor, two-axis control system apply GPS latitude and longitude data for SPA(Solar position algorithm) so we know the azimuth and altitude. it analyze data value of accuracy comparison from result. so the proposed algorithm confirm to have validity.

Real-time Audio Processing for TCP/IP in Server-Client Model (서버-클라이언트 모델에서의 TCP/IP 기반 실시간 음성 처리)

  • Lee, Hyung-ho;Jeong, Dae-young;Park, Kyung-tae;You, Byung-sek;Kim, Jeong-sig
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.619-621
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    • 2013
  • This paper is proposing a real-time audio processing system for TCP/IP with server-client. The server sends the audio data packet which is the same size each time while playing the audio data. And the client plays the received audio data from the server. In general, The receiving speed of audio data packet is faster than processing the audio data. So, the unstable playback is occurred when playing the received audio data at the moment. In order to overcome this problem, the double buffering method is proposed.

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A Study on the Reliability Improvement of Compartment Leak Test in Surface Vessels (함정 격실기밀 평가 방안에 대한 신뢰성 향상 연구)

  • Choi, Sang-Min;Park, Dong-Kyu;Beak, Yong-Kawn
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.4
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    • pp.546-551
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    • 2020
  • Generally, surface vessels have many compartments for operation and living quarters, and each compartment is an important space for the ship's survivability. During ship construction, a compartment leak test is necessary and is carried out on each vessel. However, the current test method is in doubt when looking at the actual test results. The reason is that only one pressure gauge is used for the measurement to check the air, so an uncomprehended phenomenon is detected during group compartment leak tests. From this point of view, an improved test device and method are needed. In this study, a multi-channel data acquisition device with multiple pressure sensors is proposed to detect each compartment's pressure variation or pressure drop. This test is a more confidential compartment leak test than the current method, and the test device can show real-time pressure detection values of each of the pressure sensors, which are installed in each compartment, including unmanned space.

Research about Size Effect of Solid Particles on Erosion Resistance of Aluminum Alloy and Infrared Windows (충돌 입자의 크기에 따른 알루미늄 합금과 적외선창의 입자침식 저항성 연구)

  • Hong, Yun Ky;Moon, Kwan Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.12
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    • pp.1027-1034
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    • 2016
  • In this research, experimental study about size effect of solid particles on erosion resistance is presented. A high-density polyethylene particle with a mm-sized diameter is accelerated using a two-stage light gas gun up to Mach number of approximately 3.0. An accelerated particle impacts aluminum alloy such as Al1050 and Al6061 T6, and infrared windows such as ZnS and sapphire specimens. For the aluminum alloy, craters that form on the surface of the specimens are measured to characterize the erosion resistance of the material. For the infrared windows, repetitive tests are conducted until a linear or circumferential crack is found to create damage threshold curves that define a material's erosive resistance. From the comparison of test data for various sizes of high-density polyethylene particles, it is found that erosion resistance of material is linearly dependent on the size of particles.

Synthesis and Crystallization of Hydrazinium Nitroformate(HNF) as Eco-friendly Oxidizer (친환경 산화제 HNF 합성 및 결정화 연구)

  • Kim, Jina;Kim, Min Jun;Min, Byoung Sun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.4
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    • pp.69-76
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    • 2015
  • Recently, environmental sustainability of the transitional explosives and propellants is an issue of growing importance in energetic materials. For examples, ammonium perchlorate(AP) as an solid propellants oxidizer could create a poisonous gas and atmospheric pollutions, such as HCl. Among the several oxidizers, hydrazinium nitroformate(HNF) is an effective candidate substance for eco-friendly oxidizer, which has high density, pressure index, and less smog generating property during combustion for the Divert and Attitude Control System(DACS). This study was confirmed a synthesis through various conditions, was performed for the essential data of solubility the crystallization process. Also, crystallization process such as cooling, drowning-out and sonication were performed.

Low-resistance ohmic contacts to p-$Hg_{0.7}$$Cd_{0.3}$Te (p-$Hg_{0.7}$$Cd_{0.3}$Te에 낮은 저항의 접촉을 얻는 방법에 대한 연구)

  • Kim, Kwan;Chung, Han;Kim, Sung-Chul;Lee, Hee-Chul;Kim, Choong-Ki;Kim, Hong-Kook;Kim, Jae-Mook
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.10
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    • pp.87-93
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    • 1994
  • Ohmic contacts between Au and p-HgHg_{0.7}Cd_{0.3}Te$ with low specific contact resistance have been obtained. The contact region of the wafer is first pre-heated for 5 seconds in a rapid thermal processing equipment. The temperature reaches a maximum value of about 200$^{\circ}C$ at the end of the 5 seconds. Next, a thin Au film is formed on the contact region by immersing the sample in AuCl$_{3}$ solution. the sample is then post-annealed in the same condition as the pre-heating after Pb/In pad metals are deposited on the electroless Au contacts. The specific contact resistance measured by transmission line model is 5${\times}10^{-3}{\Omega}cm^{2}$ at 80K. RBS and differential Hall measurement data suggest that the above low resistance ohmic contact is ascribed to surface traps and increased gold diffusion rate.

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Attitudes Towards Colorectal Cancer (CRC) and CRC Screening Tests among Elderly Malay Patients

  • Al-Naggar, Redhwan A.;Al-Kubaisy, Waqar;Yap, Bee W.;Bobryshev, Yuri V.;Osman, Muhamed T.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.667-674
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    • 2015
  • Background: Colorectal cancer (CRC) is the third most common malignancy in Malaysia, where data are limited regarding knowledge and barriers in regard to CRC and screening tests. The aim of the study was to assess these parameters among Malaysians. Materials and Methods: The questionnaires were distributed in the Umra Private Hospital in Selangor. The questionnaire had four parts and covered social-demographic questions, respondent knowledge about CRC and colorectal tests, attitude towards CRC and respondentaction regarding CRC. More than half of Malay participants (total n=187) were female (57.2%) and 36.9% of them were working as professionals. Results: The majority of the participants (93.6%) never had a CRC screening test. The study found that only 10.2% of the study participants did not consider that their chances of getting CRC were high. A high percentage of the participants (43.3%) believed that they would have good chance of survival if the cancer would be found early. About one third of the respondents did not want to do screening because of fear of cancer, and concerns of embarrassment during the procedure adversely affected attitude to CRC screening as well. Age, gender, income, family history of CRC, vegetable intake and physical activity were found to be significant determinants of knowledge on CRC. Conclusions: The major barriers identified towards CRC screening identified in our study were fear of pain and embarrassment. The findings have implications for understanding of similarities and differences in attitude to CRC amongst elderly patients in other cultural/geographic regions.

Correlation between Storm Characteristics and Flood Damage (우리나라 호우특성과 홍수피해와의 상관관계)

  • Park, Doo-Ho;Ahn, Jae-Hyun;Choi, Yong-Joon
    • Journal of Wetlands Research
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    • v.13 no.2
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    • pp.219-229
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    • 2011
  • In this study, Correlation analysis for relationship between storm characteristics and flood damage cost was carried out using histogram analysis. The spatial range of flood damage cost data was the whole country and 16 provinces in the Korea, and period range was 16 years, from 1994 to 2009. According to the results of this analysis, most of total flood damage cost was highest in small; middle scale rainfall events of high frequency. Based on the results of comparison among 16 provinces, the ability to prevent flood demage of metropolitan was better than that of provinces. And the storm characteristics of causing maximum flood damage cost was different from each provinces. Therefore, the construction size in flood defence measures has to be determined when flood defence measures considering the results of this study as an useful guideline.

Analysis & defence of detection technology in network Attacker (네트워크 침입자탐지기법 분석과 대응)

  • Yun, Dong Sic
    • Convergence Security Journal
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    • v.13 no.2
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    • pp.155-163
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    • 2013
  • Connection hijacking attack using the vulnerability of the TCP protocol to redirect TCP stream goes through your machine actively (Active Attack). The SKEY such as one-time password protection mechanisms that are provided by a ticket-based authentication system such as Kerberos or redirection, the attacker can bypass.Someone TCP connection if you have access on TCP packet sniffer or packet generator is very vulnerable. Sniffer to defend against attacks such as one-time passwords and token-based authentication and user identification scheme has been used. Active protection, but these methods does not sign or encrypt the data stream from sniffing passwords over insecure networks, they are still vulnerable from attacks. For many people, an active attack is very difficult and so I think the threat is low, but here to help break the illusion successful intrusion on the UNIX host, a very aggressive attack is presented. The tools available on the Internet that attempt to exploit this vulnerability, known as the recent theoretical measures is required. In this paper, we propose analysis techniques on a wireless network intruder detection.