• 아시안잔디학회지
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• 제24권2호
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• pp.156-160
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• 2010

본 연구는 식물생장조절제 trinexapac-ethyl을 켄터키블루그래스에 처리한 후 잔디의 생육특성을 조사하여, 하절기 잔디 관리 정보를 제공하고자 수행되었다. Trinexapacethyl의 처리 후 잔디의 시각적 품질, 잔디밀도, 클로로필 함량이 높아졌고, 특히 켄터키블루그래스 생육이 불량한 하절기에는 유의적인 차이를 보였다. 잔디 밀도는 대조구에 비해 평균 4개($10\;cm^2$) 높았으며, 6~7월에는 5개 이상 높았다. 클로로필 함량과 시각적 품질에서도 봄, 가을 보다는 하절기에 대조구보다 높은 품질을 유지하며, 특히 장마철과 고온기에는 하엽이 적게 발생되어, trinexapac-ethyl에 의한 하고 스트레스 경감 효과가 있을 것으로 생각되었다. 하지만, 식물생장조절제 처리 후에도 뿌리 길이의 신장에는 큰 차이가 없었다. 한편, trinexapac-ethyl 0.025 ml/$m^2$ 처리 후 켄터키 블루그래스의 예고는 처리 2주후 38%까지 억제되다가, 3주부터는 큰 차이를 보이지 않았으며, 식물생장조절제의 효과가 떨어진 4주째에도 잔디가 급격하게 웃자라는 현상은 보이지 않았다. 놀랍게도 생장조정제는 7월에 단 한 차례도 처리되지 않았으나, 7월의 잔디상태는 무처리에 비해 훨씬 안정적으로 유지되었다. 결과적으로, 켄터키 블루그래스 잔디밭에서 여름철 잔디 생육을 높이기 위해서는 봄부터 꾸준히 사용하는 것이 중요하며, 생장조정제를 0.02~0.03 ml/$m^2$의 농도로 살포하면, 약 2주 동안, 예지횟수를 최소 30%는 줄일 수 있을 것으로 예상된다. 부가적으로, 하절기 잔디 품질이 높아지면서 자연스럽게 관리자는 시비나 농약 살포 횟수를 줄일 수 있으므로 환경적으로도 많은 도움이 될 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권9호
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• pp.1303-1308
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• 2015

This study was conducted to investigate changes in blood enzyme parameters and to evaluate the relationship between insulin-like growth factor-1 (IGF-1), antler growth and body weight during the antler growth of sika deer (Cervus nippon). Serum enzyme activity and IGF-1 concentrations were measured in blood samples collected from the jugular and femoral veins at regular intervals during the antler growth period. Blood samples were taken in the morning from fasted stags (n = 12) which were healthy and showed no clinical signs of disease. Alfalfa was available ad libitum and concentrates were given at 1% of body weight to all stags. The experimental diet was provided at 9 am with water available at all times. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase during antler growth, but alkaline phosphatase concentrations increased with antler growth progression, and the highest alkaline phosphatase concentration was obtained 55 days after antler casting. Serum IGF-1 concentrations measured from blood samples taken from the jugular vein during antler growth, determined that levels of IGF-1 was associated with body weight and antler growth patterns. Serum IGF-1 concentrations were higher at the antler cutting date than other sampling dates. Antler length increased significantly during antler growth (p<0.001), and there was a similar trend to between right and left beams. Body weight increased with antler growth but was not significant. Consequently it appeared that serum alkaline phosphatase concentration was related to antler growth and both antler growth and body weight were associated positively with IGF-1 concentrations during antler growth.

• 한국산학기술학회논문지
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• 제9권4호
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• pp.878-885
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• 2008

최근에 많은 수요와 각광을 받고 있는 디스플레이 장치에서 CRT는 곡면이며 무겁고 큰 부피 때문에 LCD, PDP, OLED와 같은 평판디스플레이(FPD)로 대체되고 있다. FPD는 $0.6\sim0.8mm$ 두께의 대면적 글래스에 여러 공정을 거친 후에 최종 제품 규격으로 절단하여 제작하기 때문에 글래스의 면적이 크면 클수록 FPD의 생산성이 높다는 밀접한 관계를 갖는다. 따라서 FPD 제조 업계에서는 글래스 면적을 증가시키기 위하여 노력하고 있으며, 예를 들면, 현재 8세대 LCD인 경우 약 $2,200mm\times2,600mm$의 면적을 가진다. 이러한 글래스를 이송하는 대표적인 장치로서 공기부상 컨베어시스템은 압축공기를 이용해서 FPD용 대면적 글래스 등을 약 $0.3\sim0.5mm$ 정도 부상시켜 비접촉으로 이송할 수 있는 장치이다. 이 때 글래스와 다공질판 표면 사이의 공기 유동이 모델링되고 해석되며, 이것으로부터 글래스의 공기부양 조건이 예측될 수 있다. 글래스를 이송시 전기공급 중단에 의하여 압축공기가 공급되지 않아 부상판과 접촉이 발생하였을 때, 자기윤활 특성을 가진 다공질판 위의 글래스는 1mm 홀을 많이 가진 사각덕트 부상판 위의 글래스와 조사, 비교된다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.254-260
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• 1999

유성버스트 통신방식은 1000 km 이상의 장거리 VHF NLOS 데이터 통신 시스템을 가장 경제적인 방법으로 구현 시켜줄 수가 있다. 그러나 이 방식은 도통율이 열화 함으로 본질적으로 실용에는 부적합한 것으로 알려져 있다. 송, 수신안테나의 빔 패턴이 공간의 hot-spot을 완전히 포용할 수 있도록 함으로서 버스트의 발생빈도를 증가시키는 동시에 안테나에 유도하는 지상 잡음 전계를 효과적으로 차단함으로서 수신기의 실효 차단전압을 낮추어 시스템의 도통율(duty rate)을 개선 할수 있다. 소개구형 공동형 안테나를 개발하였다. 이 안테나는 지하에 매설하여 사용하는데 이렇게 함으로서 수직방향의 지향성이 개선되고 지상으로부터의 잡음 혼입이 효과적으로 차단된다. 이 안테나는 3dB 빔 폭이 90$^{\circ}$ 에 달하여 앙각 8-90$^{\circ}$ 로서 근거리의 hot-spot를 효과적으로 조사(illuminate) 할 수가 있다. 지표방향으로의 지향성은 최소로 억제되어 이 방향으로부터 인공잡음의 혼입을 효과적으로 차단하는데 재래식의 Yagi 보다 평균 3 dB 이상 억제된다. 이 안테나를 수신안테나로 사용하여 100 km 경로에서 시험통신을 실시한 결과 동일한 조건하에서 4 소자 Yagi 안테나를 사용한 경우에 비하여 버스트의 발생빈도와 지속시간이 각각 10%와 20% 이상 증가한 것을 확인할 수 있었다.

• 자원리싸이클링
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• 제22권2호
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• pp.22-28
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• 2013

실리콘 슬러지로부터 원심분리에 의해 1 단계로 실리콘(Si)을 분리 한 후 남게 되는 실리콘 카바이드(SiC) 농축물 내에 포함되어 있는 철과 잔존하는 실리콘을 추가적으로 제거함으로써 실리콘 카바이드의 순도를 향상 시킬 수 있는 가능성을 탐색해 보았다. 실리콘 카바이드 농축물을 대상으로 하여 염산(HCl)/수산화나트륨(NaOH)에 의한 액상 침출법과 염소 가스에 의한 기상 염소화법을 비교해 보았다. 실리콘 카바이드 농축물을 1 M 염산 수용액에서 $80^{\circ}C$에서 1 시간 동안 침출시킴으로써 회수된 실리콘 카바이드에 잔류하는 철의 농도를 49 ppm 까지 제거하였으며, 1 M 수산화나트륨 수용액에서 $50^{\circ}C$에서 1 시간 동안 침출시킴으로써 실리콘 카바이드 내 잔류하는 실리콘의 농도를 860 ppm 까지 제거하였다. 기상 염소화 반응은 직경 2.4 cm, 길이 32 cm의 전기로에 의해 가열되는 알루미나 튜브의 중심에 실리콘 카바이드 농축물을 위치시키고, 질소와 염소의 혼합가스를 흘려보내는 방식에 의해 이루어졌는데, 반응온도 $500^{\circ}C$, 반응시간 4 시간, 가스유량 300 cc/min, 염소 몰분율 10%의 조건 하에서 실리콘 카바이드 내 철과 실리콘의 잔류 농도를 48 ppm과 405 ppm 까지 낮출 수 있었다.

• 한국약용작물학회지
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• 제3권3호
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• pp.246-250
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• 1995

토천궁(土川芎)의 종묘비(種苗費) 절감(節減)과 증식율(增殖率)을 향상시키기 위하여 소목번식(掃木繁殖)에 대한 시험을 수행(遂行)한 결과를 요약(要約)하면 다음과 같다. 1, 삽수(揷穗)의 종류에 따른 발근률(發根率)은 1년생과 2년생에서 채취한 삽수간(揷穗間)에는 큰 차이가 없였고, 삽수(揷穗)의 부위(部位)에 따라 차이가 심하였으며, 첫째마디 부위(部位)를 삽목(揷木)할 패는 $90{\sim}l00%$, 둘째마디 부위(部位)는 $56{\sim}64%$ 발근(發根)되어 효과적이었다. 2. 1년생과 2년생에서 채취한 첫째마디 부위(部位) 삽목시(揷木時) 1개월 후에는 발근률(發根率) 90%이상, 삽수당(揷穗當) 발근수(發根數) 16개 이상, 발근장(發根長) 31cm이상 발육(發育)되었다. 2. 발근촉진(發根促進) 물질(物質)에 따른 발근상태(發根狀態)는 Rootone-F 발근처리(發根處理)와 NAA 250ppm에서 가장 효과적이었다. 4, 상토(床土)에 따른 발근률(發根率)은 모래가 18%로 가장 좋았으며, vermiculite와 perlite를 1 : 1혼합한 상토(床土)의 발근상태(發根狀態)와 유사하였고 기경지 밭흙은 현저히 감소되었다.

• 농업과학연구
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• 제9권2호
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• pp.569-575
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• 1982

수확기간(收穫期間)에 있어서 벼줄기의 물리적(物理的) 및 기계적(機械的) 특성(特性)을 구명(究明)하고져 일반계(一般系) 품종(品種)인 이리(裡里)348 및 진주(晋州)벼와 통일계(統一系) 품종(品種)인 서광벼 및 태백(太白)벼 4개(個) 품종(品種)을 표준시비구(標準施肥區)에서 선정(選定)하여 압축(壓縮), 인장(引張), 굽힘 시험(試驗)을 실시(實施)하고, 이어서 진주(晋州)벼 및 태백(太白)벼에 대(對)하여 부위별(部位別), 전단각도(剪斷角度) 및 함수율(含水率) 변화(變化)에 따른 전단하중(剪斷荷重)-변형특성(變形特性), 전단력(剪斷力) 및 전단(剪斷) energy등(等) 전단특성(剪斷特性)을 측정(測定) 분석(分析)한 결과(結果)는 다음과 같다. 1. 압축(壓縮), 굽힘, 인장(引張) 및 전단력(剪斷力)은 통일계품종(統一系品種)에 비(比)하여 일반계(一般系) 품종(品種)이 컸다. 2. 전(全) 부위별(部位別)의 전단력(剪斷力) 추세는 진주(晋州)벼에 있어서 하부위(下部位)의 큰 값이 상부위(上部位)로 갈수록 감소(減少)하였고, 태백(太白)벼에 있어서는 하부위(下部位)부터 지상(地上) 21cm까지 비교적 일정(一定)한 큰 값으로 나타냈다. 3. 전단면적(剪斷面積)의 증가(增加)에 따라 전단력(剪斷力) 및 전단(剪斷) energy는 증가(增加)하였고, 그 증가율(增加率)은 전단면적(剪斷面積) $10mm^2$까지는 컸으나 그 이상(以上)에서는 매우 둔화(鈍化)되었다. 4. 예취(刈取) 직후(直後)에 있어서 함수율(含水率)의 감소(減少)에 따른 전단력(剪斷力) 및 전단(剪斷)energy의 감소(減少)는 컸으나 함수율(含水率) 60%(w.b)부터는 큰 변화(變化)가 없었다.

• Journal of Plant Biology
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• 제13권1호
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• pp.33-46
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• 1970

Pinus densiflora stands are common secondary forest communities on infertile soils in Korea. The stands are results of long severe past biotic pressure such as cutting, burning and grazing. These could be regarded as biotic climax in Korea. Because of their prevalent occurrence, relatively simple species and age composition, and their domestic economic importance, study of their distributional patterns may give some basic knowledge for better utilization of land resources in Korea. To detect distributional patterns and interspecific associations ten pine stands, each of which was homogenious with respect to topography and physiognomy, were subjectively selected from pine stands in Kyunggi Province near Seoul in 1969 and were made object of this study. Four contiguous systematic samples of count for trees, shrubs and seedlings from belt transects were collected from homogeneous areas within ten natural pine stands. The belt transect was 64m or 128m in length, and 1m, 2m or 4m in width. Basic units within the transect ranged from 64 to 256. The data from the contiguous transects were analysed in terms of multiple split-plot experiment. Departure from randomness of stem distribution, i.e., pattern, was tested in terms of variance mean ratio. For the detection of association between species, correlation coefficient was calculated for different block sizes. The values of ${\gamma}$ were tested by the usual t-test. Fine trees within one of the stands showed significant regular distribution through out the blocks. Within other eight stands pines were randomly distributed at basic unit with 4$\times$4m, 2$\times$2m, 2$\times$1m and 1$\times$1m. One significantly clumped distribution at basic unit 2$\times$2m, however, was observed from one of the pine stands. These randomly distributed groups were themselves significantly regularly distributed throughout the blocks for four pine stands. For the other four pine stands, in addition to the random distribution at the basie unit(the primary random group), randomly distributed groups with 32m dimension(the secondary random groups) were also observed. Both the primary and the secondary random groups were significantly regularly distributed at the rest of blocks. Pine seedlings were not distributed randomly thoughout the blocks. Within three of the ten stands they were contagiously distributed. Important shrub species underneath pines such as Querus serrata, Q. acutissima, Leapedeza intermedia, Rhododendron Yedoense var. poukhanenae, Juniperus utilis, Rhododendron mucronulatum var. ciliatum shnwed consistently similar distributional pattern with the pine at each stand. The shrub species pairs; Rhododendron Yedoense var. poukhanenae/Quercus serrata, Rhododendron mucronulatum var. ciliatum/Lespedeza intermedia were significantly negatively associated from 1m to 4m dimensional block sizes but became significantly positively associated from 8m sized blocks on. On the other hand the shrub species pairs; Lespedeza intermedia/Robinia Pseudoacacia, and Lespedeza bicolor var, japonica/Lespedeza intermedia were also significnalty negatively associated from 1m to 8m sized blocks but became significantly positively associated from 16m sized blocks on. The associational pattern between Rhododendron mucronul tun var. poukhanenae and Lespedeza intermedia was not consistent throughout the stands. In some stands negative associations were observed throughout the blocks except NS 32. From these observatons micro-edaphic variation within the pine stands seems not to be great enough to cause distributinal difference of pine trees within the ten pine stands. Among each species and pine seedings, however, the edaphic variation within the pine stands may be great enought to cause distributional variation.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2002년도 제3회 최신 분말제품 응용기술 Workshop
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Journal of the Korean Wood Science and Technology
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• 제18권4호
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• pp.65-78
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• 1990

For the purpose of Improving the sounding boards for the conventional GAYAKUM, I was making approximately 202 specimens of radial board, 371 specimens of tangential board by cutting along the grain and the part of stem and 31 specimens of the disjointed traditional GAYAKUM made in Paulownia coreana. And it was conducted to measure specific gravity, dynamic Young's modulus, internal friction, resonant frequency, velosity of sound and width of annual ring by the method of the frexural vibration in a free-free bar in the audio frequency range. And it confirmed the juvenile wood by measuring wood fiber length of specimens. It was also conducted to investigate dynamic properties and moisture absorption by various heat-treatment and to test dynamic Young's modulus and internal friction for the disjointed conventional GAYAKUM. The results obtained were summarized as follow: 1. The Juvenile wood is located within about 7 annual rings from the pith in Paulownia coreana. 2. As increased with the specific gravity, the dynamic Young's modulus had more and more increased, but the internal friction had slightly decreased. 3. I think that radial board would be good for sounding board wood. because radial board is higher than tangential board in dynamic Young's mudulus and internal friction is lower than tangential board. 4. The value of mean dynamic Young's modulus on the conventional GAYAKUM, radial board and tangential board of 604 samples is $0.4283\pm0.037(\times10^{11}dyne/cm^2)$, $0.4316\pm(\times10^{11}dyne/cm^2)$ and $0.4234\pm0.112(\times10^{11}dyne/cm^2)$ respectively. The value of the radial board showed little higher than that of conventional GAYAKUM, but It had a similar tendency between conventional GAYAKUM and tangential board. 5. The annual ring width by four aspect is more narrow in north and west than that of others. 6. The values of specific gravity and dynamic Young's modulus in the mature wood showed higher than those of juvenile wood. 7. As the grain angle in the butt wood more increased to bark from pith, the dynamic Young's modulus were low. Then it was not good for sounding board. 8. It appeared that the heat-treatment for sounding board wood had a more effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature. 9. As increased with the temperature, the rate of moisture absorption of heat-treatment wood had decreased. In conclusion, I thought that the sounding board wood for GAYAKUM would had the most effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature using the radial board of mature wood.