• 제목/요약/키워드: level-shifting

검색결과 176건 처리시간 0.023초

Upgrade of Neutron Energy Spectrometer with Single Multilayer Bonner Sphere Using Onion-like Structure

  • Mizukoshi, Tomoaki;Watanabe, Kenichi;Yamazaki, Atsushi;Uritan, Akira;Iguchi, Tetsuo;Ogata, Tomohiro;Muramatsu, Takashi
    • Journal of Radiation Protection and Research
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    • 제41권3호
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    • pp.185-190
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    • 2016
  • Background: In order to measure neutron energy spectra, the conventional Bonner Sphere Spectrometers (BSS) are widely used. In this spectrometer, several measurements with different size Bonner spheres are required. Operators should, therefore, place these spheres in several times to a measurement point where radiation dose might be relatively high. In order to reduce this effort, novel neutron energy spectrometer using an onion-like single Bonner sphere was proposed in our group. This Bonner sphere has multiple sensitive spherical shell layers in the single sphere. In this spectrometer, a band-shaped thermal neutron detection medium, which consists of a LiF-ZnS mixed powder scintillator sheet and a wavelength-shifting (WLS) fiber readout, was looped to each sphere at equal angular intervals. Amount of LiF neutron converter is reduced near polar region, where the band-shaped detectors are concentrated, in order to uniform the directional sensitivity. The LiF-ZnS mixed powder has an advantage of extremely high light yield. However, since it is opaque, scintillation photons cannot be collect uniformly. This type of detector shows no characteristic shape in the pulse height spectrum. Subsequently, it is difficult to set the pulse height discrimination level. This issue causes sensitivity fluctuation due to gain instability of photodetectors and/or electric modules. Materials and Methods: In order to solve this problem, we propose to replace the LiF-ZnS mixed powder into a flexible and Transparent RUbber SheeT type $LiCaAlF_6$ (TRUST LiCAF) scintillator. TRUST LiCAF scintillator can show a peak shape corresponding to neutron absorption events in the pulse height spectrum. Results and Discussion: We fabricated the prototype detector with five sensitive layers using TRUST LiCAF scintillator and conducted basic experiments to evaluate the directional uniformity of the sensitivity. Conclusion: The fabricated detector shows excellent directional uniformity of the neutron sensitivity.

신축 공동주택의 주거환경에 관한 입주자 평가 (A study on the Occupants' Apprasials of Newly Consturcted Apartment)

  • 임인순
    • 한국주거학회논문집
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    • 제4권2호
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    • pp.73-83
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    • 1993
  • Recently, large APT complexes are newly constructed in Taegu city and among them, large APT complexes aggegate densly espically in Weolsung and Jisan complexes of Dalsuh-gu and Susung-gu districts. The purpose of this thesis is to perform occupants' apprasials about residential environment on the housewifes residing at new constructed APT who seem tn have different apprasials on the residential environment by the zones. The results of the investigations are as follows. 1. House possessed type and house sire got elevated in comparison with them before shifting residence in respect to residential property and it was revealed they moved to short distance in the change of their lands. And most occupants could choose their houses by looting-out and there's some difference in the choice motive according to the zones. 2. As a result of studying the relation between demographic and residential properties, there were deep differe-nces in the Possessed house type before move, possessed house size after move, preferenti-al degree of house and move plan. 3. In the degree of satisfaction on residential environment, the result was high in the order of heating facilities, water-supply and draining facilities and lighting and was low in the order of room's size, interior decoration and soundproofin. According to zones, there was a great difference in the items of room's size, privacy, heating facilities, securi-ty from calamity, ventilation, convenience of traffic and school group and facilities for extracurricular activities and the degree of satisfaction was high in Jisan zone in othe items except for room's size and heating facilities. 4. In the tenants' apprasials on tile inside and outside spaces of the zones, important factors were "Cultural Institutions", "Green Areas", "Level of Welfare Facilities" and "Utility degree of welfare facilities" and in the classification of important factors according to the zones, the first and the third factors were changed each other. I think this is because they attached importance to somethings dissatisfied in present circumstances.

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JPEG2000의 보안을 위한 카오스 시스템의 하드웨어 구현 (Hardware Implementation of Chaotic System for Security of JPEG2000)

  • 서영호
    • 한국통신학회논문지
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    • 제30권12C호
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    • pp.1193-1200
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    • 2005
  • 본 논문에서는 JPEG2000 표준에서 주파수 변환기법으로 채택된 이산 웨이블릿 변환과 선형양자화 방법을 사용하여 영상 전체가 아닌 영상의 부분 데이터만을 암호화하여 계산양을 줄이는 부분 암호화 방법을 제안하고 하드웨어로 구현하였다. 또한 계산양이 많은 암호화 알고리즘 대신 비교적 계산양이 적은 카오스 시스템을 이용함으로써 계산양을 더욱 감소시킨다. 영상 데이터의 변환 방법은 암호화할 부대역을 선택하여 영상데이터를 일정한 블록으로 만든 후 무작위로 좌/우 쉬프트 하는 방법과 두 가지 양자화 할당 방식(하향식-코드 할당방식/반향-코드 할당방식)에 따라 데이터를 교환하는 방식을 사용한다. 제안한 암호화 방법을 소프트웨어로 구현하여 약 500개의 영상을 대상으로 실험한 결과 원 영상 데이터를 부분적으로 암호화함으로써 원 영상을 인식할 수 없을 정도의 암호화효과를 얻을 수 있음을 알 수 있었다. 구현한 하드웨어 암호화 시스템은 삼성 $0.35{\mu}m$ 팬텀-셀 라이브러리를 사용하여 합성함으로써 게이트 수준 회로를 구성하였고 타이밍 시뮬레이션을 수행한 결과 100MHz 이상의 동작 주파수에서 안정적으로 동작함을 확인하였다.

전사체 프로파일을 이용한 고려 홍삼의 항당뇨 기전 연구 (Anti-diabetic Mechannism Study of Korean Red Ginseng by Transcriptomics)

  • 원해단;신은정;정성현
    • 약학회지
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    • 제52권5호
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    • pp.345-354
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    • 2008
  • This study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng extract through transcriptomics in C57BL/KsJ db/db mice. The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. At the end of treatment, we measured blood glucose, insulin, hemoglobin A1c (HbA1c), triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). RGL-treated group lowered the blood glucose and HbA1c levels by 19.6% and 11.4% compared to those in diabetic control group. In addition, plasma adiponectin and leptin levels in RGL-treated groups were increased by 20% and 12%, respectively, compared to those in diabetic control. Morphological analyses of liver, pancreas and epidydimal adipose tissue were done by hematoxylin-eosin staining, and pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. RGL-treated group revealed higher insulin contents and lower glucagon contents compared to diabetic control. To elucidate an action mechanism of Korean red ginseng, DNA microarray analyses were performed in liver and fat tissues, and western blot and RT-PCR were conducted in liver for validation. According to hierarchical clustering and principal component analysis of gene expression Korean red ginseng treated groups were close to metformin treated group. In summary, Korean red ginseng lowered the blood glucose level through protecting destruction of islet cells and shifting glucose metabolism from hepatic glucose production to glucose utilization and improving insulin sensitivity through enhancing plasma adiponectin and leptin levels.

아웃소싱 데이터베이스에서 데이터 프라이버시 및 질의 무결성을 지원하는 공간 변환 기법 (A Spatial Transformation Scheme Supporting Data Privacy and Query Integrity for Outsourced Databases)

  • 김형일;송영호;장재우
    • 정보과학회 논문지
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    • 제42권5호
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    • pp.652-663
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    • 2015
  • 위치 기반 서비스의 발전으로 인해, 일상에서 생성되는 공간 데이터의 양이 급격히 증가하고 있다. 이에 따라, 데이터 소유자의 공간 데이터베이스 관리 비용 절감을 위한 공간 데이터베이스 아웃소싱이 활발히 진행되고 있다. 데이터베이스 아웃소싱 시 가장 중요한 고려사항은 프라이버시 요구사항을 충족하고 질의 결과 무결성을 보장하는 것이다. 그러나 대부분의 데이터베이스 변환 기법은 데이터 프라이버시 보호와 질의 결과 무결성을 동시에 보장하지 못한다. 이러한 문제점을 해결하기 위해, 본 논문에서는 층밀림 변환, 회전 변환, 시프팅 변환을 활용한 공간 데이터 변환 기법을 제안한다. 또한, 데이터베이스 변환기법의 데이터 프라이버시 보호 정도를 측정하기 위한 공격 모델을 소개한다. 마지막으로, 성능 분석을 통해 제안하는 기법이 기존 기법에 비해 다양한 공격 모델로부터 높은 수준의 데이터 프라이버시 보호를 수행하며, 동시에 질의 결과 무결성을 보장함을 검증한다.

Experimental Analysis of Interactions Among Saprotrophic Fungi from A Phosphorous-Poor Desert Oasis in the Chihuahuan Desert

  • Marini-Macouzet, Constanza;Munoz, Luis;Gonzalez-Rubio, Aldo;Eguiarte, Luis E.;Souza, Valeria;Velez, Patricia
    • Mycobiology
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    • 제48권5호
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    • pp.410-417
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    • 2020
  • Fungal ecological interactions play a key role in structuring community assemblages. These associations may involve both antagonistic and synergistic relationships, which are commonly influenced by abiotic factors such as nutrient conditions. However, information for extreme, oligotrophic systems remain poor. Herein, interactions among key members of the aquatic transient fungal community (Aspergillus niger, Cladosporium sp., and Coprinellus micaceus) of a low-nutrient freshwater system in the Cuatro Ci enegas Basin, Mexico were studied. Pairwise interaction bioassays were explored in vitro under different nutrient conditions, including carbohydrates-rich, carbohydrates and amino peptides-rich, and low nutrients. Our results indicated that antagonistic patterns prevail among the studied taxa. However, nutrient-dependent changes were observed in Cladosporium sp. shifting to synergy under carbohydrates-rich conditions, suggesting changes in the fungal community composition as a result of nutrient enrichment. Remarkably, our findings contrast with previous work demonstrating mainly synergistic interactions between our tested fungal isolates and co-occurring autochthonous bacteria (Aeromonas spp. and Vibrio sp.) under low-nutrient conditions. This observation may indicate that bacteria and fungi exhibit distinct community-level responses, driven by nutrient conditions. This contributes to the knowledge of fungal community dynamics and interspecific interactions in an oligotrophic ecosystem, highlighting the relevance of nutrient-based shifts and antagonistic interactions in ecosystem dynamics.

공공시설물관리 역량 진단 모델 개발 (Development of A Model for Diagnosing Management Capabilities of Public Facility)

  • 성유경;유위성
    • 한국건축시공학회지
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    • 제20권6호
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    • pp.555-566
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    • 2020
  • 최근 국내 공공시설물의 노후화가 가속화되며 기존의 사후 유지관리 방식은 총체적이고 선제적인 시설자산관리의 개념으로 변화하고 있다. 이에 향후 공공시설물관리는 안전성 제고와 유지관리뿐만 아니라, 시설에 대한 가치 평가, 생애주기 관리 계획, 재원 마련 등의 확장된 역량 확보가 강조되고 있다. 본 연구는 국제 기준을 기반으로 공공시설물관리를 위한 역량 진단 모델을 개발하고, 관리 주체별 환경을 고려해 대응할 수 있도록 역량의 성숙도 개선 자료를 제공한다. 개발된 역량 진단 모델은 공공시설물의 10개 관리 역량, 113개의 역량 진단 요인, 관리 역량의 계량화 지수, 관리 활동을 정의하는 성숙도 수준으로 제시되었다. 향후 10년간 지속적으로 공공시설물관리의 중요성이 부각되는 상황에서 본 고에서 제시한 시설자산관리지수는 공공시설물을 운영하는 관리기관들의 강점과 약점을 파악하고 역량 향상을 위한 방향을 수립하는데 유용하게 활용될 것으로 기대된다.

엑손 포획 - 원리와 어류의 계통유전체학 및 집단유전체학으로의 응용 (Exon Capture - Principle and Applications to Phylogenomics and Population Genomics of Fishes)

  • Li, Chenhong
    • 한국어류학회지
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    • 제33권4호
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    • pp.205-216
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    • 2021
  • 한 유전좌위 또는 소수의 유전좌위에 기반한 계통발생학적 재구성은 분자 계통수/종 계통수의 불일치로 인해 오해를 불러일으킬 수 있다. 종의 구분과 종내 연구에서도 적은 유전좌위를 사용할 때 통계력 부족으로 해상도가 낮은 경우가 많이 발생한다. 엑손 포획법은 게놈 규모의 데이터를 수집하는 가장 효율적인 방법 중 하나로, 종내 및 상위 수준에서 생물의 패턴과 역사를 구명하는 연구에 크게 이바지할 수 있다. 이 논문에서는 단일 유전자 방법에서 게놈 접근으로의 전환의 진보와 게놈 기술에 비해 엑손 포획법의 적용 이점을 설명하였다. 또한 엑손 포획법의 원리를 설명하고 이 방법의 적용을 위한 상세한 제언을 기술하였다. 최종적으로, 두 가지 적용을 활용한 엑손 포획법을 설명하고 이 기술에 대한 미래 전망을 논의하였다.

순환여과 양식시스템 내 무지개송어(Oncorhynchus mykiss)의 적정 용존산소 농도평가 (Evaluation of the optimal dissolved oxygen level for rainbow trout (Oncorhynchus mykiss) in the recirculating aquaculture system)

  • 박근홍;최진서;이영훈;박정환
    • 수산해양기술연구
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    • 제59권4호
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    • pp.387-398
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    • 2023
  • Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.