• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.177-188
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• 1989

The habitat typing method of classification based on community has been developed on many forested areas in the ROCKY MOUNTAINS of WESTERN NORTH AMERICA, and is being used in providing an objective principle of guide for classification of forest sites, land classification, vertical distribution and multipurpose management of forest. I actually made a trial of forest habitat type classification - The methodology can be segmented into a number of tasks including reconnaissance, selection of stands to be sampled, location of plots, data gathering, preliminary and computer analysis, preparation of key- and map of habitat type and description for each habitat type in a view of forest management - on UNIVERSITY OF MONTANA FORESTS in order to examine whether its application is fit or not in korean forest circumstances : these are composed mainly of artificial forest and forest in the early stage of succession. The main results obtained from this study were summarized as follows 1. A hierarchical classification-Climax, Habitat type and Phases-of forest sites was developed using the habitat typing method of classification. 2. A diagnostic key is provided for field identification of the types based upon presence and number of indicator species, and forest managers could prepare a map of habitat type and classify forest habirat types by reference to it. 3. The classified habitat types were considered to be effective on providing an objective principle of guide for multipurpose management of forest including potential productivity for timber, feed productivity of forage and wildlife, selection of the right species in the right sites, application of method of treatment and so forth. 4. Forest habitat type classifications based upon extrapolation which used relict species and associated stands is considered to be suitable for korean forest circumstances and objective in studying potential vegetation, vertical and horizontal distribution of forest.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.69-79
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• 2009

Major and trace elements were analyzed in three core sediments to investigate geochemical characteristics of East Sea sediments and provenance changes during late Quaternary in Ulleung Basin. Comparing with Yellow and South Sea sediments, contents of major elements were generally similar while contents of trace elements were significantly different. Furthermore, within this basin, there were some variabilities in trace element compositions. In the western slope sediments (WS), Mo was enriched over 6 times as much as other sites. On the other hand, Zr, Nb, Hf and Ta were enriched in basin sediments (Basin), and Ca and Cs were enriched in southern slope sediments (SS). After excluding elements derived from biogenic, authigenic and diagenetic origins, the lithogenic elements (K, Ti, Cs, Zr, Nb, Hf and Ta) could be classified into three groups from the comparison of element/Al ratios among cores. The first group consisted of elements (K and Ti) that showed the nearly similar element/Al ratios among three cores. The second group contained Cs which showed significant difference between two slope sediments. The third group elements (Zr, Nb, Hf and Ta) showed highly enriched in basin relative to both slope areas. The depth profiles of metal/Al ratios in basin sediments provided the following interpretation for the compositions of sediment and their variation. From 10,000 yr B.P. to 7,000 yr B.P. two lithogenic components (volcanic ashes and western slope sediments) were mixed and deposited in the basin. After 7,000 yr B.P., however, southern slope sediments were mixed with volcanic ashes and deposited in basin area. This event of source change is nearly close to inflow period of the Tsushima Warm Current to Ulleung Basin. Thus, it might be suggested that element geochemistry in Ulleung basin sediment indicate the change of current system in the study area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.4
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• pp.249-258
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• 2001

Compressional wave velocity and electrical resistivity of muddy sediments in the southeastern inner shelf of Korea were studied using nine piston core samples. The acoustic and physical properties were measured with 10 cm depth interval. Sediment structures were examined by x-radiographs of the cored sediments. Subbottom profiles were obtained by a high-resolution acoustic subbottom profiler. Acoustic turbid layers are clearly seen on the profiles, and x-radiographs of the sediments showed degassying structures formed by gas escaping. On the basis of x-radiographic images, velocities, electrical resistivities and physical properties, the sediments are divided into gassy and non-gassy sediments. The presence of gas and degassying structures result in a marked variation in velocity and electrical resistivity. It can be concluded that velocity and electrical resistivity arep arameter to recognize gassy sediment. The velocity is important parameter to indicate gassy sediment.

• The Journal of the Acoustical Society of Korea
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• v.33 no.1
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• pp.10-20
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• 2014

To study the water-entry impact noise, on-board experiment using a small launcher firing various objects was performed in the Yellow Sea. As the launcher fires a cylindrical object from the ship vertically, generated noise is measured with a hydrophone on the starboard of Chung-hae, Marine surveyor. Three types of cylindrical objects, which have noses of flat-faced, conical, and hemisphere, were used during the experiment. The measured noise exhibits a time-dependency which can be divided into three phases: (1) initial impact phase, (2) open cavity flow phase, (3) cavity collapse and bubble oscillation phase. In most cases, the waveform of bubble oscillation phase is dominant rather than that of initial impact phase. Pinch-off time, where a cavity begins to collapse, occurs at 0.18 ~ 0.2 second and the average lasting time of bubble was 0.9 ~ 1.3 second. The energy of water-entry impact noise is focused in the frequency region lower than 100 Hz, and the generated noise is influenced by the nose shapes, object mass, and launching velocity. As a result, energy spectral density on the bubble frequency is higher in the order of flat-faced, conical, hemisphere nose, and the increase of initial energy raises the energy spectral density on the bubble frequency in the cylinder body of same shape. Finally, we compare the measurements with the simulated signals and spectrum based on the bubble explosion physics, and obtain satisfactory agreements between them.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.383-390
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• 2013

Lateral gene transfer (LGT) of genes from other bacteria into Vibrio cholerae is expectable because of the pronounced natural competence of the bacterium. In this study, quantitative aspects of LGT among the three species of Vibrio pathogenic to humans were characterized. Genome sequences of V. cholerae N16961, V. parahaemolyticus RIMD2210633, V. vulnificus CMCP6, and Escherichia coli K12 substrain MG1655 were analyzed to determine orthologous quartets of protein coding genes present in all four genomes. Phylogenetic analyses on the quartets were conducted to resolve vertical versus lateral patterns of gene polymorphisms based on congruence versus incongruence of phylogenetic trees. About 70% of the quartets could be resolved as either cohesive topology (75%) or LGT tree topologies (25%). The amount of LGT genes in Vibrio spp. appeared to be abnormally high for a genus and comparable to those of families. Patched distributions of LGT from different donors were observed on a chromosome. In the small chromosome of V. cholerae, physical linkages among LGT loci spanned half the length of the chromosome. Either accumulative selection for the donor alleles in LGT or presence of large-scale LGT events was hypothesized. These findings warrant further studies on the nature of donor-specificity of LGT alleles and its influence on evolution of Vibrio virulence to humans.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.153-163
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• 2020

Mineral and geochemical analysis were conducted on two sections (~3.5 m) of red-brown claysilt sediments covering the gneiss and granite weathering zones in Suwon-si for establishing Quaternary paleoenvironmental changes in Korea. The sections were divided into four sedimentary layers (Unit 1-4) by vertical changes in mineral composition and chemical composition. The lowermost unit 1 was a sandy sediment with a high K-feldspar content with a significant contribution of weathered bedrock. Unit 2 was a transition layer showing intermediate characteristics. Unit 3 was a reddish brown clay-silt sediment, with a total clay content of 58% on average, and the main clay minerals were illite-smectite mixed layer minerals and hydroxy-interlayered vermiculite/smectite. Unit 3 contained almost no plagioclase, while the content of kaolin minerals derived by the plagioclase weathering was higher than in the other layers. Unit 4 had similar mineral composition and chemical properties to Unit 3, but had a higher content of plagioclase and chlorite and lower content of kaolin minerals. The chemical compositions of the sections were compared with those in other regions of Korea, suggesting the eolian origin of Units 3 and 4. The paleoenvironmental change in the sedimentary section of this region was interpreted as follows. Weathered products of gneiss and granite, which are bedrocks of this region, were eroded and deposited as sandy sediments in the periphery to form the lower layers (Unit 1, 2), followed by the deposition of the claysilty rich eolian sediments (Unit 3) during the glacial. Unit 3 was chemically weathered during the warm humid climate during the last interglacial, developing a reddish brown color. After that, a eolian sediment layer (Unit 4) was deposited during the last glacial.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.591-598
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• 2000

This study was designed to analysis the airway which affects to breathing, speech and facial growth pattern in unilateral cleft lip and palate patients. Upper airway and the position of hyoid bone pattern were analyzed on the lateral cephalometric radiographs of the 78 subjects of complete unilateral cleft lip and palate group and each group was divided two sub-groups by circumpubertal growth peak and gender. These data were statistically analyzed to examine the difference between pre-circumpubertal growth peak group and post-circumpubertal growth peak one, and between male and female group. The results of this study were as follows: 1. After circumpubertal growth peak stage, the position of hyoid bone was lower than before in both male and female group. 2. After circumpubertal growth peak stage, the measurement were increased in CV3ia-APH, PNS-ad which related to the volume of pharyngeal space. This was due to the decrease of adenoid and anteroiferior growth of mandible and affected to breathing and speech after circumpubertal growth peak. 3. During circumpubertal growth peak stage, all measurements increased more in male than female group, which due to the different amount of growth in different gender. 4. The position of hyoid bone was lower in male than female group in all age group. 5. After circumpubertal growth peak stage, CV3ia-APH increased more in male. This was due to the more growth in madible of male which resulted in the activation of digastric muscle.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1
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• pp.8-16
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• 2004

An inversion method is presented for the determination of the compressional wave speed, compressional wave attenuation, thickness of the sediment layer and density as a function of depth for a horizontally stratified ocean bottom. An experiment for estimating those properties was conducted in the shallow water of South Sea in Korea. In the experiment, a light bulb implosion and the propagating sound were measured using a VLA (vertical line array). As a method for estimating the geoacoustic properties, a coherent broadband matched field processing combined with Genetic Algorithm was employed. When a time-dependent signal is very short, the Fourier transform results are not accurate, since the frequency components are not locatable in time and the windowed Fourier transform is limited by the length of the window. However, it is possible to do this using the wavelet transform a transform that yields a time-frequency representation of a signal. In this study, this transform is used to identify and extract the acoustic components from multipath time series. The inversion is formulated as an optimization problem which maximizes the cost function defined as a normalized correlation between the measured and modeled signals in the wavelet transform coefficient vector. The experiments and procedures for deploying the light bulbs and the coherent broadband inversion method are described, and the estimated geoacoustic profile in the vicinity of the VLA site is presented.

• Proceedings of the CALSEC Conference
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• 1998.10b
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• pp.585-594
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• 1998

이미 전자상거래(EC)가 시간적ㆍ공간적 제약을 극복하고 국경을 초월한 새로운 교역시장 (Cyber Market)으로 등장하고 있으며 세계 자동차 산업은 표준부품의 공동개발 및 조달을 통해 중복투자 방지, 신차개발기간 단축 등 전략적 제휴를 통한 공조ㆍ공생체계 구축을 경쟁적으로 추진하고 있으나 국내 자동차업계는 제품개발, 부품조달, 판매 및 A/S 등 모든 부문을 독자적으로 해결함으로써 경쟁력 제고에 역행하는 경향이 있다. 또한 자동차 선진국과는 달리 국제 경쟁력 강화를 위한 CALS/EC 정보 기반 기술의 실질적인 활용이 미흡한 실정이다. 이러한 현실을 개선하기 위해 최근에 자동차공업협회(KAMA)와 현대, 대우, 기아 자동차 3사는 자동차 산업 CALS 추진 모델(Autopia)의 구축을 추진하고 있다. 추진 내용은 자동차 산업의 전체 Life-Cycle인 제품기획 단계부터 설계, 생산, 구매/조달, 고객지원 단계등 전 분야를 3개 부문(신차개발 프로세스, 구매조달 프로세스, 고객지원 서비스)으로 구분되어 있다. 신차개발 프로세스 부문은 차세대 PDM을 통하여 제품개발 사이클 단축을 추구하며 STEP을 통한 범용적 설계정보 교환 체계 구현이 기반이 된다. 또한 업무 흐름의 불투명성으로 인한 업무의 불균형 현상 타파와 설계 변경의 효율적 대응을 위하여 Workflow Management가 동시공학에 바탕을 두고 도입 적용되어야 한다. CAD 데이터를 비롯한 방대한 데이터의 효율적 관리를 위해서는 각 프로세스별로 독립된 정보를 체계적으로 관리할 수 있는 통합 환경(Integrated Data Environment)을 구성하여 각 프로세스에 걸쳐 데이터의 처리효율을 증대하여야 한다. 신차개발 부문의 핵심 기술이면서도 현업 적용이 초기 단계인 Digital Mockup과 Virtual Reality의 적용을 위해서는 3D 모델링이 기본 설계 방법으로 적용되어야 하며 이를 통한 어셈블리 및 부품구조의 관리가 이루어져야 한다. 구매조달 프로세스 부문은 자동차 업계의 공통 EDI/EC 네트워크 구축을 통한 경제적인 인프라 구조와 함께 부품 조달 체계의 간소화를 추구함으로써 자동차 산업의 대외 경쟁력 강화가 이루어 질 수 있다. 공개구매 시스템의 구축을 통하여 완성차별로 전속 계열화된 수직적인 부품조달 체계와 업체간 정보공유의 폐쇄성을 제거할 수 있고 완전 경쟁에 의한 우량 협력업체 발굴 기회의 확대가 용이하다. 이를 통하여 궁극적으로는 Global Vendor망의 구축이 실현될 것이다. 종합물류 시스템이 구현되면 판매는 경쟁체제, 물류는 공동화가 됨으로써 국가적으로 물류 비용의 절감이 엄청날 것으로 예상된다. 전국에 산재되어 있는 1,000여개의 대리점과 7,000여개의 정비업소를 대상으로 한 정비부품 EDI/EC 시스템이 구축되면 고객 서비스의 효율 향상과 함께 정비업소의 물류 및 재고 비용의 감소, 조달 속도의 향상, 조달 업무의 간소화 등의 효과를 보게 될 것이다. 고객지원 서비스는 정비정보 시스템, 산업정보 시스템, 쇼핑몰 시스템, 등록대행 시스템등을 통하여 일반 국민들이 피부로 느낄 수 있는 시스템으로 구축 되어야 할 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.76-83
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• 2017

Fish respond sensitively to light, so it is possible to develop fish management technology using this feature. In this study, we developed a light-based fish barrier and analyzed itsblocking effect using the difference in illuminance for the major fish species in Korea, bass and bluegill. The light was generated by a light emitting diode and the facility was installed vertically from the bottom. Considering the fish's ability to travel upstream, the flow rate was divided into three stages (0.2, 0.1, and 0.05 m/s). To prevent the learning effect, an experiment was carried out with fish that had rested for more than one day in a rearing tank. The experiment was carried out in such a way as tocompare the number of fish which travelled upstream after the introductionof the fish barrier and that of the fish which travelled upstream after itsremoval. It was also carried out after sunset to increase the effectiveness of the barrier. According to the results of the experiment, the fish blocking effect depending on the difference in illuminance was high and, overall, the blocking rate for bass was lower than that for bluegill. Based on the total size of the experimental population, the blocking rates for bass and bluegill were 96.33% and 99.00%, respectively. Based on the number of fish that travelled upstream, the blocking rates for bass and bluegill were 91.73% and 98.73%, respectively.