• 대한방사선기술학회지:방사선기술과학
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• 제5권1호
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• pp.35-43
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• 1982

The authors surveyed the cassettes in 10 general hospitals and compared in experimentation on performances of 6 kinds of cassettes manufactured with several materials in order to discover the present condition and performance of the cassettes being used at present. And the authors got the following results. 1. In distribution of the cassettes in use, Okamoto's(Japan), Picker's and Titan's(U.S.A.) were more than others classified by the manufacture. The rate of using high speed was 72.0%, par speed 28.0% classified by types of intensifying screens in the cassettes and the rate of the year in use for $4{\sim}5$ years was 40.0%, $6{\sim}7$ years 24.0% classified by the years in use. 2. The results of the screen-film contact test were that tile ordinary was 42.7%, the good 36.0%, and the poor 21.3%. 3. The results of the test for light leakage were that fogged area appeared on 1 side or more in 84.0% films. 4. In Aluminum equivalents of front plate, the cassettes with a front plate consisting of carbon fiber were fewest, and the ones of bakelite and aluminum were fewer in order 5. In compared results of the exposure dosage for same density of the films, the exposure of the cassettes used carbon fiber for the material on the front plate was smallest and bakelite, auminum was smaller in order.

• 아시안잔디학회지
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• 제18권1호
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• pp.29-36
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• 2004

The efficient refinement of seed is required to reduce the cost and labor input in artificial propagation of wild plant. This study was carried out to develop methods for collecting and refining tiny seeds from wild plants. For obtaining Phragmites communis seeds, the inflorescence was cut into small fragments using a Straw Cutter and subsequently detached pappus hairs from seed coat by Hammer Mill. The primary refined seeds were passed 1.0 mm sieve. The screened seeds were subjected to Seed Blower with wind speed of 0.25 mㆍsec-1 to collected intact and well-ripen seeds. The seeds of Imperata cylindrica were refined as follows. Inflorescences were cut using a Straw Cutter first. The pappus was removed from cut fragments using a Hammer Mill and subsequently subjected to Seed Scarifier at 500rpm for 60 sec. for further separation. The separated seeds were passed 1.0 mm screen and collected after blowing with Seed Blower of wind speed of 0.15 mㆍsec-1. When the amount of seed was too little to refine with Seed Scarifier and Blower, the procedure was slightly modified from the procedure described above. The crude seed mixture obtained from Hammer Mill step was hand-refined roughly and then immersed into cone. (95%) sulfuric acid for 2 min. and collected floating portion after dilution of sulfuric acid solution 100 times with tap water. The collected seeds were dried and passed 0.149 mm sieve. During seed refining process using mechanical or sulfuric acid treatments, a small portion of damaged seed were evolved, however, the amount was not noticeable as compared to the total amount of collected seeds. Because the germination percentages between hand-refined seeds and seeds refined by above methods were not statistically different, the developed procedures for refining tiny seed of wild plants are helpful to reduce the cost and labor input in artificial propagation of two species.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.199-201
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• 2013

골프존과 같이 스포츠가 가지는 활동성과 게임의 흥미요소를 결합한 '스포테인먼트'는 시간과 지리적 제약이 비교적 작다는 점에서 앞으로 새로운 비즈니스 아이템으로 많은 발전가능성을 가지고 있다고 볼 수 있다. 본 연구에서는 센서 기술을 활용하여 야구 시뮬레이션 게임 개발을 목표로 1차적으로 투구분석과 타자의 스윙분석을 할 수 있는 시스템 개발을 위한 설계를 제안하고자 한다. 주요 기능으로는 스피드건을 통한 구속의 측정이 아닌 센서의 작동 시간을 통해 구속을 측정하고 투구의 궤적을 추적하는 기능을 그래픽으로 재구현하고, 이와 유사한 방법을 통해서 타자의 스윙 및 타구의 추적 기능을 제안하고자 한다. 이 야구시뮬레이션 게임은 성공적인 비즈니스 아이템으로 성장한 골프존과 같이 스포츠와 게임을 결합한 "실내 스포테인먼트"의 하나로 발전할 것으로 예상된다.

• Annals of Clinical Neurophysiology
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• 제2권1호
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• pp.8-12
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• 2000

Purpose : The rapid development and wide popularity of Digital EEG(DEEG) is due to its convenience, accuracy and applicability for quantitative analysis. These advantages of DEEG make one hesitate to use analog EEG(AEEG). To assess the advantage of DEEG system utilizing AEEG(DAEEG) over conventional AEEG and the clinical applicability, a DAEEG system was developed and applied to animal model Methods : Sprague-Dawley rat as status epilepticus model were used for collecting the EEG data. After four epidural electrodes were inserted and connected to 8-channel analog EEG(Nihon-Kohden, Japan), continous. EEG monitoring via computer screen was done from two rats simultaneously. EEG signals through analog amplifier and filters were digitized at digital signal processor and stored in Windows-based pentium personal computer. Digital data were sampled at a rate of 200 Hz and 12 bit of resolution. Acquisition software was able to carry out 'real-time view, sensitivity control and event marking' during continuous EEG monitoring. Digital data were stored on hard disk and hacked-up on CD-ROM for off-line review. Review system consisted of off-line review, saving and printing out interesting segment and annotation function. Results: This DAEEG system could utilize most major functions of DEEG sufficiently while making a use of an AEEG. It was easy to monitor continuously compared to Conventional AEEG and to control sensitivity during ictal period. Marking the event such as a clinical seizure or drug injection was less favorable than AEEG due to slowed processing speed of digital processor and central processing unit. Reviewing EEG data was convenient, but paging speed was slow. Storage and management of data was handy and economical. Conclusion : Relatively simple digital EEG system utilizing AEEG can be set-up at n laboratory level. It may be possible to make an application for clinical purposes.

• 한국농공학회논문집
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• 제59권6호
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• pp.1-8
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• 2017

The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. We analyzed the climatic conditions around seven major reclaimed land areas in Korea, which have a plan to install advanced horticultural complexes. The characteristics of heating load through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. The overall heat transfer coefficient of the experimental greenhouse with the aluminum screen and multi-layer thermal curtain averaged $3.79W/m^2^{\circ}C$. It represents a 44 % heat savings rate compared with plastic greenhouses with a single covering, which was significantly lower than that of the common greenhouses with 2-layer thermal curtains. This is because the experimental greenhouse was installed on reclaimed land and wind was stronger than the inland area. Among the total heating load, the transmission heat loss accounted for 96.4~99.9 %, and the infiltration loss and the ground heat exchange were low. Therefore, it is necessary to take countermeasures to minimize the transmission heat loss for greenhouses constructed in reclaimed lands. As the reclaimed land is located on the seaside, the wind is stronger than the inland area, and the fog is frequent. Especially, Saemangeum area has 2.6 times stronger wind speed and 3.4 times longer fog duration than the inland area. In designing the heating systems for greenhouses in reclaimed lands, it is considered that the maximum heating load should be calculated by applying the wind coefficient larger than the inland area. It is reasonable to estimate the operation cost of the heating system by applying the adjustment factor 10 % larger than the average in calculating the seasonal heating load.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.414-416
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• 2003

메모리 제품의 사용 환경은 점차적으로 High Speed/High Density화됨에 따라 현 Comp. Test 환경으로 Field 환경을 모두 수용하기가 어려워지고 있다. 따라서, Component Level에서 다양한 실장 System을 이용한 Screen 방법이 요구 되고 있다. 다양한 환경에서 Test를 실시하기 위해서 필수 불가결한 조건은 온도(Temperature)를 자동으로 제어(Control)할 수 있는 기능이 필요하게 되었다. 이에, 현재 사용하고 있는 방법은 Chamber나 히터를 이용하고 있으나 온도 제어가 보다 용이하고 정밀한 기능이 요구됨에 따라 열전반도체(Thermoelectric semiconductor)원리를 이용한 온도 제어 장치 도입을 위한 연구가 진행되었다. 본 논문에서는 그 개발 현황 및 평가 결과를 근거로 신규 Component실장 Tester에 효율적으로 도입 적용 가능함을 제시 하고자 한다. 또한, 향후 기타 Tester 및 산업용 설비 등에 까지 확대적용 가능함으로써 전자부품(메모리)의 품질 향상 및 설비투자 Cost절감 효과가 기대 된다.

• 공업화학
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• 제33권4호
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• pp.402-407
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• 2022

실험계획법을 이용하여 MOF-5 합성공정의 최적화에 대한 연구를 수행하였다. 먼저 전구체의 농도를 최적화 하기 위하여 혼합물 설계법을 이용하였다. 합성에 사용되는 세 가지 전구체인 terephthalic acid, zinc acetate dihydrate, N,N-dimethylformamide의 농도비를 extreme vertices design methods로 최적화 하였다. MOF-5 합성을 위한 최적의 농도는 1 mol : 2.7 mol : 40 mol로 예측되었다. 이후, 온도, 시간 및 교반 속도와 같은 합성 반응 조건이 합성에 미치는 영향을 분석하기 위해 다단계 요인 설계법을 사용하였다. 수행된 통계 분석에 따라 교반 속도는 후속 연구에서 제외되었다. 합성시간과 온도를 고려한 합성 공정 최적화는 중앙 조성 설계법을 이용하였다. 13번의 합성 실험을 통해 도출된 2차 모델 방정식을 이용하여 결과를 추정하였다. 설계에 사용된 모델에 의하면 119 ℃ 및 10.4 h 조건에서 합성된 MOF-5가 최대의 결정화도를 가지는 것으로 예측되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.135-135
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• 2022

For abnormal weather disaster and building constructions, the shading stress could occur in crops more often. Those shading stress can effect on rice growth characters. Therefore, we investigated the shading effect on rice growth characters. Shading treatments were treated using shading screen as 35, 55, 75 and 100%. To check the shading effect on rooting after transplanting, shading stress treated after transplanting for 20 days as 35, 55 and 75%, And 35, 55, 75 and 100% of shading were treated 60 days after transplanting to check the growth characters. After transplanting, the shading stress effected on leaf and root growth. At 19 days after transplanting, leaf number reduced by shading stress. In 35, 55 and 75% shading stress, the leaf number reduced as 0.38, 0.45 and 0.9 respectively compared to control treatment. And root length was also reduced as 0.39, 0.6 and 1.93 cm respectively compared to control treatment. The plant height was slightly increased in 35 and 55% and reduced in 100%. Leaf growth speed per day was reduced as 0.0167 according to shading stress. And root growth speed also reduced as 0.0426 according to shading stress. The shading stress during vegetative stage effected on plant height and tiller number. In 35, 55 and 75% of shading stress, the plant height was slightly increased but it was reduced in 100%. Tiller number was significantly reduced by shading stress. According to 10% of shading stress, about 7% of the tiller number was reduced. However, leaf color did not change by the shading stress. The leaf area in 2^nd to 4nd leaf from new leaf reduced as 297 and 1044 in 75 and 100% of shading stress and increased as 70 and 99 in 35 and 55%. These leaf area change was affected by both the length and width of the leaf.

• 한국산업융합학회 논문집
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• 제21권3호
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• pp.141-147
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• 2018

In a time when product development cycles are getting shorter and shorter, many companies are making efforts to develop products with high reliability in a short period of time, accelerated life test is widely used as a method to quickly evaluate reliability. Accelerated life test reduces the test life or the life of the product from the observed data by shortening the lifetime of the product or abruptly lowering the performance under the worse condition than the actual condition in order to shorten the test cost or the test time. In this paper, BL3640A-06P+RB35, DC12V model, which is used in the support device of an automatic rotation type digital signage, which display various information such as textures and images on a display screen in a public place or a commercial space, BLDC motors were subjected to a constant stress test and at the rotational speed of 1rpm, $180^{\circ}$ rotation and reverse rotation under actual use conditions, the stress was imposed on the rotating speed of 2rpm and the weight of the actual installed product from 22.2kgf to 10kgf were installed. The lifetime of the actual use environment condition is 23,545 hours and the rotation speed is accelerated. The life time of the acceleration condition with the additional weight is 1,380 hours. The acceleration factor is calculated as 17.06, the one year guarantee test day is 235 days to 14 days, of the period from 470 days to 28 days, and the third year from 704 days to 42 days. The test date of the BLDC motor was tested on the shortened test date, and the rotational speed and the current value were measured. It is found that there is no defect even if it operates as the test date corresponding to the specified one year warranty period and the 3 year accelerated life test which is experimented. Using the statistical technique of the regression analysis the expected time for the motor to defect to #4 samples was 20 years.

• 한국위성정보통신학회논문지
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• 제11권4호
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• pp.1-9
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• 2016

본 연구는 PPI Scop 레이더 장치에서 수신된 정보신호 중 영상신호 분리와 합성과정을 거쳐 영상신호 생성, 심볼생성, 양성 잔상 신호 생성 결합 처리 과정을 거쳐 레이더 정보 분석용 화면에서 운영자의 판별 용이성, 가독성 향상과 더불어 운영 편리성을 획기적으로 향상시킬 수 있는 기술적 구현방안에 대하여 2가지 형태로 연구하였다. 첫째, FPGA기반 고속 프로세스 정보처리 연산시스템으로 구성된 하드웨어 자원을 이용하여 시스템의 고속화 안정성을 갖추도록 하였다. 둘째, 소프트웨어 자원인 함수곡선 알고리즘과 지능화된 알고리즘을 연계 구현하여 레이더 정보, 분석 시스템에서 필요한 제약요건을 충족할 수 있도록 연구하였다. 기존의 레이더 시스템에서 구현이 불가능 하였던 프레임 단위 영상데이터 분석을 위해 영상캡처와 저장, 레이더 정보 표출 영상을 MPEG4 동영상으로 저장을 할 수 있도록 하였다. 연구의 핵심은 영상 양성 처리 함수곡선 알고리즘을 통해 육안판별에서 관찰 목표물, 특정 감시 대상물체 정보를 강조, 지연표출 및 색상 표현도 할 수 있도록 하였다. 고속 FPGA기반에 탑재된 ARM Processor Support in Pro ASIC3 적용하여 지능화된 알고리을 부분적으로 탑재시켜 시스템의 신뢰성과 효율 제고로 운영자 정보판독 가독성 향상은 물론 최적화된 고해상도 영상, 고속의 정보 분석 및 다양한 정보 표출을 유지할 수 있도록 구현하였다.