• Title/Summary/Keyword: Detective

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Investigation of Radiation Effects on the Signal and Noise Characteristics in Digital Radiography (디지털 래디오그라피의 신호 및 잡음 특성에 대한 방사선 영향에 관한 연구)

  • Kim, Ho-Kyung;Cho, Min-Kook;Graeve, Thorsten
    • Journal of Biomedical Engineering Research
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    • v.28 no.6
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    • pp.756-767
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    • 2007
  • For the combination of phosphor screens having various thicknesses and a photodiode array manufactured by complementary metal-oxide-semiconductor (CMOS) process, we report the observation of image-quality degradation under the irradiation of 45-kVp spectrum x rays. The image quality was assessed in terms of dark pixel signal, dynamic range, modulation-transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). For the accumulation of the absorbed dose, the radiation-induced increase both in dark signal and noise resulted in the gradual reduction in dynamic range. While the MTF was only slightly affected by the total ionizing dose, the noise power in the case of $Min-R^{TM}$ screen, which is the thinnest one among the considered screens in this study, became larger as the total dose was increased. This is caused by incomplete correction of the dark current fixed-pattern noise. In addition, the increase tendency in NPS was independent of the spatial frequency. For the cascaded model analysis, the additional noise source is from direct absorption of x-ray photons. The change in NPS with respect to the total dose degrades the DQE. However, with carefully updated and applied correction, we can overcome the detrimental effects of increased dark current on NPS and DQE. This study gives an initial motivation that the periodic monitoring of the image-quality degradation is an important issue for the long-term and healthy use of digital x-ray imaging detectors.

A study on Marine Protected Areas as Fisheries Management Tools (어업자원 관리수단으로서의 해양보호구역제도에 관한 연구)

  • Chae, Dong-Ryul;Nam, Su-Min
    • The Journal of Fisheries Business Administration
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    • v.42 no.3
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    • pp.41-61
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    • 2011
  • Marine protected Areas(MPAs) are specially designated zones of the sea that are designed to secure operation of ecosystem function and to restore marine ecosystem to the original state by excluding all detrimental human activities. MPAs have been proposed in many countries as means of realizing sustainable fisheries and recently MPAs are newly receiving attention as precautionary measure for global warming and climate change. The purpose of this paper is to examine the possibility of MPAs as fisheries management tools through a wide range of literature analysis and to suggest necessity of fisheries purpose of MPAs in Korea. Establishment of marine protected area can accompany various economic benefits such as restoration of marine environment, preservation of habitats, promotion of marine tourism and so on. Especially, a lot of case studies suggested that MPAs may bring out benefits to the fishing industry as a result of enhanced stocks. Fisheries benefits of MPAs on targeted species include increased abundance, increased mean individual size and age, increased reproductive output, enhanced recruitment inside and outside refuge, maintenance of genetic diversity of stocks, and enhanced fishery yields in adjacent fishing grounds, so called spill-over. MPAs for ecosystem conservation and protection of coastal wetland have been applied appropriately and effectively, however, the Korean MPAs system is still detective due to absence of fisheries purpose MPAs. Finally, suggestions for Korean MPAs can be summarized as following four recommendations; to establish number of small-scale MPAs rather than few large MPAs, to designate island and its surrounding areas as reserve, to consider MPA design with stock enhancement program, and to undertake co-management with Eochon-Gye, the traditional coastal community in Korea.

Monitoring Result of Rock Mass Behavior during Excavation of Deep Cavern (대심도 지하 공간 굴착시의 암반거동 - 일본 SUPER KAMIOKANDE의 사례 -)

  • Lee Hong-Gyu
    • Tunnel and Underground Space
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    • v.16 no.1 s.60
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    • pp.11-25
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    • 2006
  • The world's largest nucleon decay experiment facility is constructed at a depth of approximately 1,000 meters, in the Kamio Mine, Japan. The excavated cavern is consisted of a cylinder of 42.4 m high and a semi elliptical dome of 15.2 m high, with a bottom diameter of 40 m. The total excavation volume is approximately $69,000\;m^3$. Because of the character as a large cavern excavation in deep underground, there is many unknown factors in rock mechanics. Based on the results of rock test and numerical analysis, the monitoring of rock mass behavior accompanying progress of construction was performed by various instruments installed in the rock mass surrounding the cavern. The monitoring data was used in the study of measures for cavern stability.

A study on Compound Sensibility of Odors and Colors for Aromatic Fabric Design (방향성 소재 디자인을 위한 향과 색의 복합 감성 연구)

  • 우승정;조길수
    • Science of Emotion and Sensibility
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    • v.6 no.2
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    • pp.37-47
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    • 2003
  • The objectives of this study were to find the relationship between the olfactory sense such as perfume and sense of sight and how it affects the sensibility based on the fact that ,senses are compound feeling from detective parts of human body. First, to build the emotional rate stale we selected the 19 pairs of adjective from the previous studies that overlaps smell, color, and clothes and added one pairs of related clause. Then each pair was divided into 7 level of emotional stage. In the experiment by the selected 15 man and woman from the visual design major student of Hong-ick Univ each student was given floral, jasmin, lavender, papaya and asked them to pick one color from I.R.I Hue & Tone chart for each smell. Then, analyzed the emotional rating of selected color for given smell. The emotional structure of smell and color consists five parts; 'Esthetics', 'Romance', 'Character', 'Intensity', 'Nature', There were significant differences in frequencies of selected colors for each given smell and gender difference also affected the color selected. Average value of emotional rating scale of smell and color was ,similar to the results from previous studies on relationship between smell and emotion.

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A Study on the Effectiveness of Criminal Profiling (범죄자 프로파일링의 효용성 평가)

  • Jung, Se-Jong
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.686-694
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    • 2014
  • Criminal profiling, also known as offender profiling is designed to predict the characteristics of unknown criminal perpetrator through an analysis of the crime scene. Until now, there has been conflict about the effectiveness of criminal profiling among academics. In this study, 113 police investigators', working in serious crime divisions, were interviewed about their experiences with criminal profiling, and their belief about its effectiveness. 63.7% of the respondents agreed that criminal profiling is a valuable investigative tool and 62.8% agreed that profilers are valuable to criminal investigations. A total of 31.8% agreed that profilers help the police identify offenders and 15.0% agreed that there is no risk of profiler misdirecting and investigation. 61.5% of the respondents who had reported using a profile agreed that profiling is helpful and 71.4% told that they would use profiling again in the future.

The Test for Verifying a Tip-Over Analysis of a Dry Storage Cask (건식저장용기에 대한 전복해석의 검증시험)

  • Kim Dong-Hak;Seo Ki-Seog;Lee Ju-Chan;Cho Chun-Hyung;Jang Hyun-Kee;Choi Byung-Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.3
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    • pp.245-253
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    • 2006
  • A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

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The Knowledge and Power Expressed in the Movie : Focused on the structure of 'binary oppositions' (영화<장미의 이름>에 나타난 '지식과 권력'의 속성 탐색 : 기호학의 '이항적 대립' 구조를 중심으로)

  • Lee, Seora;Jeong, Eui Jun
    • The Journal of the Korea Contents Association
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    • v.15 no.8
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    • pp.194-208
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    • 2015
  • The Power and Knowledge are attractive materials that could be used in all of cultural content genre with storytelling. Because he, whether or not own knowledge, could be an important tool of narrative strategy for popularity keeping with a confrontation and conflict. This study aimed to explore the power and knowledge appearing in . For this purpose, it used the structuralistic methodologies of Saussure and Levi-Strauss, analyzing binary oppositions between the characters mainly connected with the knowledge and power. Three categories was analytic object, 'Place(abbey, book repository)' 'Debate on laughter', 'The argument for heresy.' As a result, we found the three materials had narrative strategy fully following binary oppositional structure. In that movie, which was deployed in a basis with knowledge and power, we eventually found that contemporary reality veiled the truth was paradoxically revealed with these narrative strategy. And we confirmed that it was very important the attribute of knowledge and power in narrative processing.

Improvement of the Working System for Forensic Agents (과학수사요원의 근무제도 개선방안)

  • Cho, Min-Sang;Jo, Hyun-Bin
    • The Journal of the Korea Contents Association
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    • v.15 no.4
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    • pp.188-196
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    • 2015
  • Areas of forensic have been used as a tool in many fields of police investigation, detective, such as research relating to the criminal investigation. Despite it is failure to obtain a central role and status, forensic is nonetheless necessary. This study recognizes the importance of police and forensic activities, and in reviewing the level of support for actual condition of science and forensic investigations, and it has tried to find the problems. Based on this, this study discusses development plans of the working system to explore whether it can improve the efficiencies of forensic activities from the realistic restrictions. These days, one of the main problems that police forensic activities encounter is lack of labor and human resources on the arrested. Therefore, this study aimed to looking for realistic ways to improve efficiencies of forensic agents First, changing the working system and the restructuring the command system requires a long-term perspective. In other words, a regional forensic system is required. Second, the establishment of a Police Investagation Specialization to ensure the professionalism of the investigation is necessary. Third, the system should improve forensic specialties. Fourth, the R&D organization should established to improve the capability for forensic investigations.

DEVELOPMENT OF THE SOLAR EUV TELESCOPE ENGINEERING MODEL FOR A SATELLITE (인공위성 탑재용 극자외선 태양망원경(EUVT) EM 개발)

  • 이선민;장민환;이은석
    • Journal of Astronomy and Space Sciences
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    • v.20 no.4
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    • pp.327-338
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    • 2003
  • The aim of this paper is to describe the results of the study on the extreme-ultra-violet (EUV) solar telescope, which is designed to. a possible satellite mission. Since the EUV band can not be observed on the ground, the observation in EUV should be performed in space using a satellite or a rocket. Design of the Extreme-Ultra-Violet solar Telescope (BUVT) in this study is based on "Designing a small-sized engineering model of solar EUV telescope for a Korean satellite" (Han et al. 2001). Our EUVT design is satisfied with the requirements for a satellite in size and input voltage. The major goal of the study is to confirm if we can detect the specific wavelength (58.4nm to 62.9nm) with the EUVT. We describe re-designing of the EUVT to decrease a shelter ratio. Also we describe the technics in the optic system and the detector, which were used to manufacture the EUVT. We explain the detective program, which is to calculate the amount of the solar radiation, and the image data processing system.ng system.

Measurement of Imaging Property of Flat-Panel Detector

  • Matsumoto, Masao;Suekane, Kouji;Maeda, Kouji;Ogata, Yuji;Inamura, Kiyonari;Kanai, Kouzo;Kanamori, Hitoshi
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.385-388
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    • 2002
  • We measured and evaluated digital, pre-sampling and overall imaging properties (characteristic curves, Modulation Transfer Function (MTF), Wiener spectra (WS), Noise Equivalent Quanta (NEQ) and Detective Quantum Efficiency (DQE)) for the direct type and indirect type of Flat-Panel Detector (FPD). First, the digital and overall characteristic curves of the both types of FPD had more wide dynamic range than that of the S/F system. Second, the pre-sampling and overall MTF of the direct-type FPD were superior to those of the indirect-type FPD. Third, for identical exposures, the digital and overall WS of the direct-type FPD were similar or worse than those of the indirect-type FPD, and for larger exposure, the digital WS of the both types of FPD were smaller, but overall WS of the both types of FPD were larger. Fourth, the digital and overall NEQ and DQE of the direct-type FPD were worse than both NEQ and DQE of the indirect-type FPD at lower spatial frequencies, but were better at higher spatial frequencies.

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