• 대한방사선기술학회지:방사선기술과학
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• 제20권2호
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• pp.34-43
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• 1997

There are 4 types of equipment in diagnostic radiography. These are single phase, three phase, inverter type and condenser type X-ray generators. It is very confusing to make an adequate exposure factor and to know the usage of different type of X-ray generators. In this experiment, I explored a comparative study of outputs in 4 different type of X-ray units. I expect that this experiment could be helpful for manufacturer to make both the X-ray equipment better, In terms of Ideal exposure factors, thereby reducing the patient dose. Experimental results are as follow : 1) X-ray output The ratio of X-ray output of single, three phase and inverter type of X-ray generator was 1 : 1.6 : 2 without absorber and 1 : 2 : 2.6 with 20 mm aluminium absorber. 2) Beam quality The X-ray beam quality of single phase generator was proved to be softer than three phase and inverter type of generators by 0.4 mmAL and 0.55 mmAl HVL respectively. 3) Reproducibility Linearity of X-ray output Retroducibility of X-ray output met the regulation below CV 0.05 and linearity also met the regulation below 0.1 in 4 types of diagnostic X-ray generators. 4) The comparison of incident dose Three phase X-ray generator was 20% higher than two other X-ray generators in radiation dose to make same film density.

• 대한수의학회지
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• 제40권1호
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• pp.173-186
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• 2000

This experiment was carried out to investigate the tendency of incident diseases in pre- and post- weaning piglets which ages were 1 to 7 weeks old by laboratory diagnosis and in order to minimize death in preweaning piglets and of stunted growth in postweaning piglets. The result of this experiment used as the basic data for the preventive programs in pre- and post- weaning piglets and were as follows: 23 different diseases diagnosed in 331 cases were studied in relation to age, season, and etiology. The most prevelent diseases of pre- and post- weaning piglet were Colibacillosis(79 case, 23.9%) and the major diseases were Salmonellosis(44 cases, 13.3%), Anemia(37 cases, 11.2%). Unknown viral disease(20 case, 6.1%), Rota viral infection(19 case, 5.8%), Porcine reproductive & respiratory syndrome(PRRS; 15 case 4.5%), Transmissible gastroenteritis(TGE; 12 case, 3.6%). The gastrointestinal disease, such as Colibacillosis, Salmonellosis, Swine dysentery, Clostridial infection, Rotaviral infection, TGE, Porcine epidemic diarrhea(PED) and Ballantidiosis occured pro- dominently in the period of pre- and post- weaning, which were 178 cases(53.8%) and not related to occurrence according to age and season. The respiratory diseases were Atrophic rhinitis(AR), Swine enzootic pneumonia, Pneumonic pasteurellosis, Pleuropneumonia, Branchopneumonia, PRRS and which were 48 cases(14.5%) and higher prevalent in spring and summer. The viral diseases was 73 cases(22.1%) that occurred in the period of 5 weeks piglet and prevalent mainly in spring. The bacterial diseases were 188 cases(56.8%) that were not related to occurrence according to age and season. Salmonellosis was prevalent in 3 to 5 weeks piglet and mainly occurred in summer. Viral septicemia and rotaviral infection occurred after 5 weeks piglets intensively and 3 to 5 weeks, respectively. And the both occurred without relation with season. PRRS occurred after 4 weeks piglet and prevalent in summer. TGE occurred 1 to 7 days old piglets and prevalent in spring and winter. Hematologic values of anemia was decrease in number of Red Blood Cell, concentration of Hemoglobin and Hematocrit. Amikacin, cephalothin, colistin, norfloxacin were effective to E coli, and amikacin, cephalothin, nortloxacin, neomycin were effective to Salmonellra spp. but clindamycin, erythromycin, penicillin, sulfonamides were resistant to E coli and Salmonella spp.

• 한국방재학회 논문집
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• 제9권6호
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• pp.51-56
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• 2009

안전 및 품질 평가시스템은 유해물질 재난을 예방하기 위해 유해물질의 생산 저장 수송 취급에 매우 중요하다. 현재 유해물질은 플라스틱, 가정의 세척제, 비료 또는 석유관련제품으로 우리의 일상생활 어디에서든지 존재하고 있다. 그러나 유해물질은 인간이나 환경에 누출되었을 때 매우 위험한 물질이다. 유해물질은 석유기반 경제시대에 매우 폭넓게 사용되고 있다. 우리나라의 환경부는 전세계적으로 유해물질의 유형이 약 십만개가 넘을 것으로 추산하고 있다. 또한 매년 4백개 이상의 새로운 물질이 개발되고 있다. 따라서 유해물질 관리측면에서 우리는 유해물질 사고로부터 안전한가에 대해 의문이 제기될 수 있다. 1984년에 발생해 6,400명이 넘는 사망자와 3만명 이상의 부상자를 낸 인도 보팔사고는 이러한 우리의 유해물질 안전에 대한 불안을 증폭시키는 대표적인 사례이다. 우리나라는 최근 산업의 고도화로 각종 유해물질 사고가 빈번하게 발생하고 있다. 따라서 낙후된 유해물질 관리시스템을 자기관리가 가능한 안전시스템으로 전환하기 위한 위험평가시스템의 구축이 우리사회에 요구되고 있다. 본 연구는 유해물질 위험평가시스템 구축을 위한 기반을 제공하기 위해 지난 10년동안 유해물질 관련시설에서 발생한 사고사례들을 연구의 대상으로 하여 유해물질 시설사고의 특성을 빈도분석, 교차분석 등의 통계기법을 적용하여 분석하였다. 분석결과 사고시설 유형과 연도, 계절, 발생지역, 사망자 발생간 관계가 있는 것으로 나타났다.

• Current Optics and Photonics
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• 제4권4호
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• pp.330-335
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• 2020

We have investigated optimization of the working distance (WD) for a highly miniaturized imaging probe for endoscopic optical coherence tomography (OCT). The WD is the axial distance from the distal end of the imaging probe to its beam focus, which is demanded for dimensional margins of protective structures, operational safety, or full utilization of the axial imaging range of OCT. With an objective lens smaller than a few hundred micrometers in diameter, a micro-optic imaging probe naturally exhibits a very short WD due to the down-scaled optical structure. For a maximized WD careful design is required with the optical aperture of the objective lens optimally filled by the incident beam. The diffraction-involved effect was taken into account in our analysis of the apertured beam. In this study, we developed a simple design formula on the maximum achievable WD based on our diffraction simulation. It was found that the maximum WD is proportional to the aperture size squared. In experiment, we designed and fabricated very compact OCT probes with long WDs. Our 165-㎛-thick fiber-optic probes provided WDs of 3 mm or longer w ith reasonable OCT imaging performance.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4209-4214
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• 2022

Precise modelling of the interaction of ions with materials is important for many applications including material characterization, ion implantation in devices, thermonuclear fusion, hadron therapy, secondary particle production (e.g. neutron), etc. In this study, a new approach using the Geant4 toolkit in combination with the Bayesian regularization (BR) learning algorithm of the feed-forward neural network (FFNN) is developed to estimate the range of ions in materials accurately and quickly. The different incident ions at different energies are interacted with the target materials. The Geant4 is utilized to model the interactions and to calculate the range of the ions. Afterward, the appropriate architecture of the FFNN-BR with the relevant input features is utilized to learn the modelled ranges and to estimate the new ranges for the new cases. The notable achievements of the proposed approach are: 1- The range of ions in different materials is given as quickly as possible and the time required for estimating the ranges can be neglected (i.e. less than 0.01 s by a typical personal computer). 2- The proposed approach can generalize its ability for estimating the new untrained cases. 3- There is no need for a pre-made lookup table for the estimation of the range values.

• IEIE Transactions on Smart Processing and Computing
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• 제3권4호
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• pp.221-225
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• 2014

Low power RF devices, such as RFID and Zigbee, are important for ubiquitous sensing. These devices, however, are powered by portable energy sources, such as batteries, which limits their use. To mitigate this problem, this study developed RF energy harvesting with W-CDMA for a low power RF device. Diodes are required with a low turn on voltage because the diode threshold is larger than the received peak voltage of the rectifying antenna (rectenna). Therefore, a Schottky diode HSMS-286 was used. A prototype of RF energy harvesting device showed the maximum gain of 5.8dBi for the W-CDMA signal. The 16 patch antennas were manufactured with a 10 dielectric constant PTFT board. In low power RF devices, the transmitter requires a step-up voltage of 2.5~5V with up to 35 mA. To meet this requirement, the Texas Instruments TPS61220 was used as a low input voltage step-up converter. From the evaluated result, the achievable incident power of the rectenna at 926mV to operate Zigbee can be obtained within a distance of 12m.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1054-1058
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• 2006

We report the synthesis and electroluminescent properties of new aromatic compounds as hole-transporting materials based on phenothiazine, such as 1,4-diphenothiazyl-benzene [DPtzB], 1,4-diphenothiazyl-xylene [DPtzX] and 9,10-diphenothiazyl-anthracene [DPtzA]. DPtzB thin film exhibited photoluminescence (PL) maximum emission peak and emission shoulder at 450 and 475nm, and maximum emission at 447nm without emission shoulder was found in DPtzX thin film. When DPtzA was excited by incident light of 359nm, DPtzA showed strong PL emission at 417nm and weak emission at 600nm. Luminance efficiency of DPtzB, DPtzX and DPtzA-based electroluminescence (EL) devices was 3.57, 3.46 and 0.47cd/A, and power efficiency of DPtzB, DPtzX and DPtzA-based EL devices was 1.48, 1.26 and 0.20lm/W.

• 대한토목학회논문집
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• 제33권4호
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• pp.1455-1462
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• 2013

본 연구에서는 유공부 형상, 상대유수실 폭, 파형경사 등에 따른 유공케이슨의 소파특성을 2차원 및 3차원 실험을 통해 고찰하였다. 파랑이 직각으로 입사하는 경우, 유사한 유공율 조건에서 횡 slit이 종 slit에 비해 반사계수가 약간 작게 계측되었으나 그 차이는 크지 않았다. 그리고 파형경사가 큰 경우가 작은 경우에 비해 약간 낮은 반사계수를 보였다. 경사 입사파 조건에서도 유공율이 유사할 경우, 유공부 형상에 따른 제체 전면의 파고 차이는 거의 발생하지 않았다.

• 한국보건간호학회지
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• 제14권2호
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• pp.332-341
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• 2000

Children's accident is a largely preventable public health problem. Little is known. however, about population-based incident and outcome of pediatric accident. From 1997.9 through 1998,8. admission data from emergency center in I city were collected. 1418 patient from 0 through 13 years of age were selected. All children with unintensional accidental problems were identified through coded sheet which categorizes epidemiologic characteristics. The specific purposes of this study are analysis about the characteristics of pediatric accidents. And it aims to produce the basic data necessary for accident prevention policy development. The results of this study were as follows; 1. The number of male children$(62.6\%)$ were higher than female children$(37.4\%)$ 2. The age group from 1 to 3 years represents the highest proportion$(45.4\%)$ of every accidents except on traffic accident. 3. The highest proportion of accident were as follows occured during the June-August$(34\%)$, Sunday$(22.6\%)$, and 17-21 p.m. $(37.2\%)$ 4. The main causes of accident include general trauma$(70.9\%)$, environmental accident$(l6.8\%)$. and traffic accident$(l2.1\%)$, 5. Preschool age group represents more than half$(65.4\%)$ of traffic accident. 6. environmental injury includes burns $(46.6\%)$, foreign body$(43.6\%)$, exposure to poisonous materials$(6.3\%)$. and bite(3.3) This results could be used to develope prevention programs and assist in accident prevention system development. And also these data substantiate that accident prevention program decrease safety-related injury rate in preschool age group must be concentrated on enhancing access to a system to have a significant effect. Furthermore, it is necessary for accident prevention. So several suggestions are described here: 1. Development of parent's educational program for accident prevention and safety education should be done actively. 2. Home safety surveillance system should be initiated. 3. The initiation of children's accident report system could be contribute the analysis and the reduction of accident.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1853-1856
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• 2013

$TiO_2$ hollow nanoparticles (HNPs) and their light scattering effect which influences on the photoelectric conversion efficiency of a dye-sensitized solar cell (DSSC) were investigated. When only HNPs were employed in DSSC as the anode layer material, the conversion efficiency (e.g., 0.96%) was the lowest, possibly due to scattering loss of incident light. However, DSSC fabricated by using HNPs as a scattering overlayer on the $TiO_2$ nanoparticles (P-25), showed higher conversion efficiency (4.02%) than that without using HNPs (3.36%).