• Journal of Plant Biology
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• 제22권3호
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• pp.59-62
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• 1979

Distribution and standing crops of seedling and sapling as undergrowing tree were investigated in a Pinus rigida forest. The relative light intensity(RLI) on the ground level was 3.9∼59.3% which indicates a wide range. Under this range of RLI seedlings and saplings distribute well in the stand. Eight trees were selected from the stand, then measured dry weight of stem, branches and leaves using thestratified clip technique. A possible relationship between the diameter at the bottom of the tree (Do) and standing crops was investigated. As Do increased from 0.8cm (T1) to 7.2cm (T8), the standing crops also increased from 42.6g to 7,410.4g. Since semi-log values between Do and standing crops clearly indicates a straight line, there is close relationship between these two factors. Therefore it is possible to estimate the standing crops of seedling and sapling by measuring Do. Productive structure shows that phytosynthetic layer is located above the 1/2 height of the tree and maximum photosynthetic layer apperars on 2/3 level in height.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.398-402
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• 1987

In the process industries control & organization consist of interconnections on different levels. The process controls that run these industries are a collection of well-defined functions in the form of standard modules interconnected by a communication network. Real-Time(throughput, response time), operator communication, flexibility, back-up and recovery needs have distribute organization of both system hardware and software. Multi-level systems are aften advocated for controlling complex systems, such as, electric, water, oil, gas plants. In practice, these systems encompass computers and person with their various communication requirements and limitations. Hence, Careful mutual adaptation of computer communications and organizational structure is necessary. This paper concentrates on these interactions between process control and organization on the basis of industrial case studies.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 춘계 종합학술대회 논문집
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• pp.234-240
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• 2004

Now that the e-commerce users are explosively increasing, there is always followed by a sharp increase in load from the e-commerce system and the heavy traffic on the network, where leads to the delayed service for the client's request. The natural consequences contain decreasing customer satisfaction and weakening the business's competitive position in markets. Therefore, we'll need to study the e-commerce system in due consideration of the operational efficiency and response speed. This study includes a design of e-commerce system, with a hierarchical structure based on the local server, which has the capability of caching necessary to distribute the system load, makes a proposal concerning a split web-cache algorithm devoted to the local web server to finally give an analysis of the performance through the appropriate trial.

• 로봇학회논문지
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• 제11권4호
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• pp.217-225
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• 2016

Dynamic Positioning (DP) is used to automatically maintain the position and heading of a floating structure subjected to environmental disturbances. A DP control system is composed of a motion controller to compute the desired force and moment and a thrust allocator to distribute the computed force and moment to multiple thrusters considering mechanical and operational constraints. Among various thruster configurations, azimuth thrusters or propeller/rudder pairs tend to make the allocation problem difficult to solve, because these types of propulsion systems include nonlinear constraints. In this paper, a dynamic positioning strategy for a twin-thruster ship that is propelled by two azimuthing thrusters is addressed, and a thrust allocation method which does not require a numerical optimization solver is proposed. The applicability of the proposed method is demonstrated with an experiment using an autonomous boat.

• Steel and Composite Structures
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• 제19권6호
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• pp.1483-1499
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• 2015

With the improvement of the quality of construction materials and the development of construction technologies, large-scale long-span steel frame buildings have been built recently. The P.E.B system using tapered members is being employed as an economically-efficient long-span structure owing to its advantage of being able to distribute stress appropriately depending on the size of sectional areas of members. However, in December 2005 and in February 2014, P.E.B buildings collapsed due to sudden loads such as snow loads and wind gusts. In this study, the design and construction of the P.E.B system in Korea were analyzed and its structural safety was evaluated using the finite element analysis program to suggest how to improve the P.E.B system in order to promote the efficient and rational application of the system.

• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.75-81
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• 2011

Today, FPD manufactures are eager to develop larger and larger glass to become the prime market leader. To follow this need, larger AMHS(Automated Material Handling System) development is essential. The radical increase of glass/cassette weight puts a lot of pressure on stocker robot's dual arms, which can cause a damage of expensive glasses and contaminate a clean room facility. In this paper the axiomatic design method is used to institute a design guideline to evenly distribute a pressure throughout the stocker robot structure.

• ETRI Journal
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• 제36권4호
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• pp.643-653
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• 2014

To reduce interconnect delay and power consumption while improving chip performance, a three-dimensional integrated circuit (3D IC) has been developed with die-stacking and through-silicon via (TSV) techniques. The power supply problem is one of the essential challenges in 3D IC design because IR-drop caused by insufficient supply voltage in a 3D chip reduces the chip performance. In particular, power bumps and TSVs are placed to minimize IR-drop in a 3D power delivery network. In this paper, we propose a design methodology for 3D power delivery networks to minimize the number of power bumps and TSVs with optimum mesh structure and distribute voltage variation more uniformly by shifting the locations of power bumps and TSVs while satisfying IR-drop constraint. Simulation results show that our method can reduce the voltage variation by 29.7% on average while reducing the number of power bumps and TSVs by 76.2% and 15.4%, respectively.

• 한국세라믹학회지
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• 제33권7호
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• pp.743-754
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• 1996

In this study (Ba1-xPbx)TiO3 was synthesized by modified oxalate process in order to prevent vaporization of PbO through low temperature synthesis climinate Cl ion reproducibly substitute Pb for by and uniformly distribute ion (Ba1-xPbx)TiO3 was synthesized by coprecipitation of lead acetate barium acetate and ammonium titanyl oxalate have been used as starting materials. The substitution of Pb for Ba was reproducibly possible synthetic temperature of perovskite structure becomes lowed as the Pb concentration increases and fine partic-les (specific surface are :7.2 cm2/g) were obtained, BaTiO3 powders calcined at 90$0^{\circ}C$ for 3 hours were cubic from in XRD analysis and as Pb content was increases evident split of tetragonal peaks could be observed The optimum conditions to synthesize (Ba,Pb)TiO3 powder are the followings ; synthesis temperature (5$^{\circ}C$)

• 대한원격탐사학회지
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• 제1권1호
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• pp.39-51
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• 1985

The study was emphasized on application of the digital image processing techniques for lineament analysis. The major lineament of the study area belongs to Choogaryong faults which many geologists have studied since 1903. Also the lineament is so significant in geological views, because the lineament runs through Seoul area. The several image processing methods such as gradient, Laplacian and spatial filter have been applied, and the spatial filtering is most suitable method for lineament analysis among them. The lineaments distribute predominently in the N20.deg.-30.deg.E trend and N80.deg.-90.deg.W trend which have the conjugated relationship each other, and it coincides with the Gyeongsang conjugate system. The circular structure of study area was developed by cooling circular joint.

• Design & Manufacturing
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• 제13권4호
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• pp.40-44
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• 2019

The light diffusion component spreads the light from one point evenly over a large area. Various types of light diffusion parts such as films and lenses are applied in the high-tech industries such as LCD display devices, lighting devices, and solar energy generation. Among these, a diffuser sheet (Diffuser Sheet) has a function to uniformly distribute the light, and various studies have been conducted to improve its function. The shape of the conventional light diffusion pattern is mainly made of a dot or hemispherical shape. In this study, a rectangular cone-shaped structure having a light diffusion function and an advantage of controlling the angle of refraction of light was fabricated by using a solenoid indentation process. The change in shape of the indentation structure was analyzed.