• 산업기술연구
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• 제19권
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• pp.31-42
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• 1999

This paper presents a method for evaluating the performance of a leaf spring suspension and an air spring suspension systems for trucks in terms of ride and handling. Leaf springs, which generally have non-linear progressive force-deflection characteristics, are modeled using beam and contact elements. The leaf spring analysis model shows good correlation with experimental results. Each component of an air spring suspension system, which is a single leaf, air spring, height control valve, compressor and linkages, is modeled appropriately. Non-linear characteristics of air spring are accounted for using the measured data, and pressure and volume relations for height control system is also considered. The wheel rate of the air suspension is taken lower but roll stiffness is taken higher than those of leaf springs to improve ride and handling performance, which is verified through driving simulations.

• 제어로봇시스템학회논문지
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• 제8권2호
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• pp.151-157
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• 2002

A 3-dimenstional automatic solder paste inspection system is described that can be used to find defects occurring in solder paste printing process. This system extracts height and volume information very fast as well as area of solder paste printed, using multiple slit ray projection and Galvano-mirror scanning. Methods are presented on calibration of camera and slit projector, real-time image processing of multiple slit images, determination of reference height, and extraction of paste height information are proposed. Performance of the system was successfully demonstrated through field tests.

• Plant Resources
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• 제7권1호
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• pp.15-21
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• 2004

This study was conducted to evaluate the effect of mecoprop-wp concentrations on weed control, growth characters and yield in flax, after 7cm and 14cm of plant height it to the field. The major weeds were Alopecurus aequalis var. a murensis (kom) ohwi, Persicaria hydropiper spach, Lamium amplexicaule L, Stellaria alsine Grimm var. undulata ohwi, Eleusine indica(L.) Gaertn. Flax yield were increased somewhat more with 250g/10a mecoprop-wp at 7cm of plant height than the other treatment and by hand weeding treatment of mecoprop-wp, 250g/10a at 7cm of plant height was slightly harmful for the flax with recommended concentration, On the other hand, all treatments were harmful in the double dosage level.

• 한국산림과학회지
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• 제100권3호
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• pp.483-493
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• 2011

본 연구는 산지계류 및 산림유역의 산사태 등의 재해를 예방과 함께 생태적 보전을 지키기 위해 시공되는 기존 사방댐의 생태투과율과 생태차단높이의 분석에 의한 생태연결성에 대한 유형분류에 대한 기초자료를 제공함에 목적이 있다. 분석결과, 평균 표준도, 규격별 표준도 및 시공사례에 의한 평균생태투과율은 전체적으로 에코필라사방댐(64.0%) > 와이어로프사방댐(13.9%) > 슬릿트사방댐(10.9%) > 다기능사방댐(7.2%) > 중력식사방댐(0.4%)의 순으로 나타났다. 사방댐의 생태차단높이는 중력식사방댐(3.2 m) > 다기능사방댐(1.7 m) > 와이어로프사방댐(1.2 m) > 슬릿트사방댐(0.6 m) > 에코필라사방댐(0.0 m)의 순으로 나타났으나, 생태차단높이의 기준은 명확하지 않았다. 사방댐의 생태투과율과 생태차단높이의 분석을 이용하여 생태연결성 유형을 구분한 결과, 사방댐은 생태연결형, 생태부분연결형 및 생태단절형으로 구분할 수 있었다. 즉 (1) 생태연결형 사방댐은 하천 바닥에서부터 생태계가 개방되고, 횡단면 전체의 투과율이 20%이상으로 포유류, 파충류, 어류 및 양서류 등의 동식물의 생태적 연결성이 양호한 형태, (2) 생태부분연결형은 하천바닥으로부터 차단높이가 2 m 이하이고 횡단면 전체의 투과율이 5% 이상 20% 미만으로 상당부분 개방되고, 어도가 설치되어 양서류, 어류, 파충류 및 포유류 등의 동물의 소통이 어느 정도 가능한 형태, (3) 생태단절형은 하천바닥으로부터 차단높이가 2 m 이상이고, 횡단면 전체의 투과율이 5%미만으로 산지계류를 통한 동 식물의 생태적 연결이 거의 단절되는 형태로 구분하였다. 이상과 같이 사방댐의 유형분류는 산지계류의 수변생태계를 고려한 연구개발이 지속적으로 이루어져야 할 것으로 사료된다.

• 대한토목학회논문집
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• 제33권1호
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• pp.377-386
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• 2013

공동주택이 고층화됨에 따라, 고층 공동주택 거주자들은 이익을 누리는 반면에 건축물 배후를 이용하는 사람들은 주거 환경에서 많은 문제를 경험하게 되었다. 본 연구에서는 공동주택 중에서도 특히 공동주택의 높이가 도시경관에 미치는 영향에 대해 알아보기 위하여 사례 연구 및 비교 분석을 수행하였다. 그 결과, 해안지역의 공동주택 단지나 건축물들에 한해서는 그에 적합한 높이관리의 규제를 마련하여 여러 가지로 난립되어 있는 높이에 관한 제도들을 총괄적으로 관리 할 수 있는, 불안요소들을 모두 아우를 수 있는 방안이 모색되어야 할 것으로 판단된다.

• 대한치과교정학회지
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• 제22권1호
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• pp.179-203
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• 1992

This study was designed to analyze nasal respiratory patency and its correlation with skeletal components in growing children with anterior crossbite. The subjects consisted of 40 control patients, 24 nose breathers with anterior crossbite and 18 mouth breathers with anterior crossbite. The mean age was 11.4 years in the control group, 10.1 years in nose breathing group and 9.5 years in mouth breathing group. The results were as follows, 1. In anterior cross bite group, and nasal respiratory airflow rates (N.R.A.R.) was significantly lower than that of control group regardless of nasal decongestants application. 2. The N.R.A.R. of mouth breathers with anterior crossbite in male group was significantly lower than that of mouth breathers, but increased to the level of control group after nasal decongestants application. But in female group, the N.R.A.R. was significantly lower in mouth breathing group at both conditions. 3. Mouth breathing group showed smaller anterior vertical nasal cavity height (ANS-ANS'), lower upper anterior facial height ratios (N-sp'/N-Me) and higher maxillary occlusal plane ratios (OL-ML/ML-NL) than those of nose breathing group with anterior crossibte. 4. Items showing nasal height (ANS-ANS', PNS-PNS'), anterior upper facial height (N-sp') was were strongly correlated with N.R.A.R. at 150 pascal in inspiration. But item showing maxillary occlusal plane ratios (OL-ML/ML-NS) was negatively correlated with N.R.A.R. at 150 pascal in inspiration. 5. There were forward tongue position in mouth breathing group, but it was not significantly correlated with N.R.A.R. at 150 pascal in inspiration.

• 한국작물학회지
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• 제60권1호
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• pp.17-22
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• 2015

A total of CNU 28 hybrids were developed at the CNU Corn Breeding Lab. were evaluated to identify new cultivars in botanical characteristics, fresh yield per 10a and taste qualities. Most of these hybrids were stable in environmental stresses such as lodging, disease and insects. Stem height ranged from 115.0 to 239.3 cm, and ear height ranged from 30.7 to 107.0 cm. The ear height to stem height ratio was showed low than 50% of standard as a stable plant type to lodging. The range of ear length was 14.2 cm to 23.0 cm. Especially, CNU 13H-73 was very longest ear as a 23 cm. The fresh yield per 10a was high in purple of CNU13H-79 hybrid than control hybrid Miheuckchal, and CNU13H-73 in white hybrid was similar Yeonnong check hybrid. The 100-kernel weights in CNU13H-3 and CNU13H-9 hybrids were higher than that of the control hybrid. CNU13H-98 among hybrids had a 100-kernel weight of 20.32 g, which was heavier than that of the control hybrid Daehackchal Gold 1. The average pericarp thickness was $41.4{\mu}m$, CNU13H-46 among hybrids had a very thin pericarp as a $35.5{\mu}m$. The mean sugar content of the used hybrids was 14.95 brix%; CNU13H-73 and CNU13H-55 had higher than Mibak2 as a control hybrid.

• 생물환경조절학회지
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• 제10권1호
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• pp.55-60
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• 2001

일몰 후 적색 및 원적색 광처리가 토마토 묘 소질에 미치는 효과를 조사하기 위해 24일간의 광처리 기간동안 12일 간격으로 묘의 초장, 제1절간장, 줄기직경을 측정하였고, 실험 마지막 날에는 묘의 뿌리와 줄기를 분리 건조하여 각 건물중을 측정하였다. 적색광 처리는 식물의 초장을 억제시키는 것으로 나타났고, 원적색광 식물의 초장신장을 촉진하는 결과를 보였다. 적색 및 원적색광 처리가 식물의 초장에 미치는 효과는 광처리 시간이 10분 또는 20분이든 큰 차이가 없었다. 또한, 적색광 처리된 식물의 줄기직경이 대조구 및 원적색광 처리된 식물의 줄기 직경보다 큰 것으로 나타났다. 적색광 처리는 원적색광 처리 및 대조구에 비해 줄기·뿌리의 건물중비가 작았다. 토마토 묘의 충실도에 미치는 광처리 효과는 적색광 처리가 가장 우수한 것으로 나타났고, 원적색광 처리된 묘의 충실도가 가장 낮았으며 광처리 없는 대조구는 그 중간정도의 충실도를 나타내었다.

• 한국해양공학회지
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• 제33권1호
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• pp.68-75
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• 2019

A low-crested structure (LCS) is an excellent feature not only because it provides shore protection but also because it is fully submerged. However, in order to properly control waves, it is necessary to maintain a certain range of crest height and width in consideration of the wave dimensions at the installation area. According to previous studies, an LCS has some wave breaking effect when the crest width is more than a fourth of the incident wavelength and the crest depth is less than a third of the incident wave height. In other words, if the crest width of the LCS is small or the crest depth is large, it cannot control the wave. Therefore, when an LCS is installed in a large sea area with a great tidal range in consideration of the landscape, waves cannot be blocked at high tide. In this study, the hydraulic performances of a typical trapezoidal LCS with a constant crest height and a low-crested structure with an adjustable crest height, which was called a tide-adapting low-crested structure (TA-LCS) in this study, were compared and evaluated under various wave conditions through hydraulic experiments. It was found that the wave transmission coefficients of the TA-LCS at high tide were lower than the values for the typical LCS based on empirical formulas. In addition, the hydraulic performances of the TA-LCS for wave reflection control were 12.9?30.4% lower than that of the typical LCS. Therefore, the TA-LCS is expected to be highly effective in controlling the energy of incoming waves during high tide even in a macro-tidal area.

• Geomechanics and Engineering
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• 제36권1호
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• pp.27-37
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• 2024

The roof-filling body system stability plays a key role in gob-side entry retained (GER). Taking the GER of the 1103 belt transportation roadway in Heilong Coal Mine as engineering background, stability analysis of roof-filling body system was conducted based on the cusp catastrophe theory. Theoretical results showed that the current design parameters of 1103 belt transportation roadway could ensure the roof-filling body system stable during the resistance-increasing support stage of the filling body and the stable support stage of the filling body. Moreover, a verified global numerical model in FLAC3D was established to analyze the failure characteristics including surrounding rock deformation, stress distribution, and plastic zone. Numerical simulation indicated that the width-height ratio of the filling body had a great influence on the stability of the roof-filling body system. When the width-height ratio was greater than 0.62, with the decrease of the width-height ratio, the peak stress of the filling body gradually decreased; when the width-height ratio was greater than 0.92, as the distance to the roadway increased, the roof stress increased and then decreased. The theoretical analysis and numerical simulation findings in this study provide a new research method to analyze the stability of the roof-filling body system in GER.