• 한국습지학회지
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• 제23권2호
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• pp.122-132
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• 2021

본 연구에서는 우리나라의 갯벌에서 조사대상으로 삼는 멸종위기야생생물이자 해양보호생물, 흰발농게(Austruca lactea)의 전체 개체수 추정 방법을 검토하였다. 일반적으로 무한모집단에 대한 전수조사는 불가능하며 이는 갯벌 내 제한된 서식처에서 개체수를 추정하더라도 마찬가지이다. 표본으로부터 추정되는 서식 밀도 역시 다양한 생물학적, 생태학적 요인들로 인해 높은 변동성을 보인다. 서식처 경계와 면적은 측정 오차뿐만 아니라 생물의 주기성이나 리듬 활동(주야, 간만 주기 등)에 따라서도 달라진다. 따라서 밀도와 서식처 면적으로 산출되는 전체 개체수는 일시적인 것으로 간주되어야 한다. 이 같은 추정은 인천 송도 갯벌에서 3년 간 관찰된 흰발농게(A. lactea)의 평균 밀도와 표준오차 범위 그리고 공간분포의 시공간적 변동성에 근거하면 타당한 것으로 볼 수 있었다. 본 연구에서는 로지스틱 회귀모형의 출현 확률인 50%를 기준으로, 서식처 보존 가치의 중요성을 반영하는 잠재적 서식처 면적을 전체 개체수 추정의 대안으로 제시하였다. 보편성을 갖춘 모형으로부터 예측되는 잠재적 서식처는 대상종의 주요 환경조건이 급격하게 변하지 않는다면 시간에 따라 일정한 모습을 유지할 것이다. 특정종을 대상으로 개발되는 모형은 추후 서식처 복원/조성 사업에서도 원하는 생물의 정착을 유도하는데도 활용이 가능할 것으로 기대된다.

• Journal of Mechanical Science and Technology
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• 제16권11호
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• pp.1550-1557
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• 2002

Diode laser sensor for measuring gas temperature and species concentration in combustion chamber was developed using 2.0 tim distributed feed back lasers. To evaluate the measurement sensitivity of diode laser sensor system, CO2 survey spectra near 2.0 Um were measured and compared with the calculated one. This diode laser absorption sensor was applied to measure gas temperatures in a premixed flat flame of CH$_4$-air mixture. Experimental results were in good agreement with the values by an R-type thermocouple within 6.12%. In addition, successful demonstration of measurement of gas temperature and species concentration in a soot flame showed the promising possibility of diode laser absorption sensors for practical combustion system with non-intrusive method.

• 전자공학회논문지A
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• 제30A권7호
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• pp.75-81
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• 1993

In this paper, New type of Static Edge Triggered D Flip-Flop Circuits which are effective for the sequencial selecting and addressing of Matrix type Electrodes being applied to Flat Display Devices is proposed by the Design Technique using the Transmission Characteristics of Feedback Transistors and Charge Back Up Function. These Circuits composed of 2-4 less transistors in number than Conventional Static D Flip Flop's have some advantages that the Maximum Transition Time of Clock Signals allowed is increased by 100-450 times more than that of the Conventional circuit at 100KHz Clock Frequence and Circuit Safety is much increased by making the wider ranges, 1-4V, of Clock Levelas a Non-operating periods than 3-3.2V ranges in case of the Conventional Circuit at 10MHz clock frequence. By these advantages, These circuits can be very effectively used in case that clock signal has long transition time, especially on the low frequency operation.

• 소성∙가공
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• 제11권2호
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• pp.147-154
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• 2002

The tension levelling Process is Performed to elongate the strip plastically In combination of tensile and bending strain so that all longitudinal fibers In the strip have an approximately equal amount ofn length and undesirable strip shapes are corrected to the flat shape. Thus paper is concerned with a simulation of the tension levelling process based on the analysis of tile unit model for the tension leveller. Analysis technique such as the sequential analysis of the unit model is suggested and verified with the assembly analysis of the unit model for the effective arts economic analysis of the full set of the tension leveller. Analysis of the full tension levelling Process using sequential unit models Is carried out for steel strips with the shape defect and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.

• 한국지반공학회지:지반
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• 제9권1호
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• pp.69-78
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• 1993

The Coulomb and Rankine theories have been usually used for design of retaining walls, in which the earth pressures have been assumed as a triangular distribution For the rigid retaining w리1 with inclined bacuace and horizontal surface backfilled by cohesionless soils, the analytical method of earth pressure distribution has been newly suggested by using the concept of the flat arch. The active thrust obtained by this method agrees well with those by the existing theories, except the Rankine solution. The analyzed results show that the height to the center of pressure depends mainly on the inclination of the back wall and the wall friction, instead of 0.33H, where H is the wall height.

• 한국환경과학회지
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• 제18권8호
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• pp.911-918
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• 2009

Electromagnetic interference (EMI) is defined as the interaction phenomena of electromagnetic waves scattered from a large structure or complex terrain. In this study, the propagation of linear wave is modeled with ray theory, direct simulation Monte Carlo (DSMC), and some classical theories on flat plates. The wave physics of reflection, refraction, and diffraction are simulated for the investigation of front and back scattering of the one-dimensional plane wave from a tower with ray theory and DSMC, respectively. The effect of rotating disk idealized from the real wind-turbine blades is modeled with a simplified version of the classical electromagnetic theory as well as DSMC based on the ray theory.

• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.106-112
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• 2007

Advanced back-end processing requires the integration of low-k dielectrics and Cu. However, in the presence of an electric field and a temperature, positive Cu ions may drift rapidly through dielectric and causing reliability problems. Therefore, in this paper, Cu+ drift diffusion in two low-k materials and silicon oxide is evaluated. The drift diffusion is investigated by measuring shifts in the flat band voltage of capacitance-voltage measurements on Cu gate capacitors after bias thermal stressing. The Cu+ drift late in $SiO_{x}C_{y}\;(2.85{\pm}0.03)$ and Polyimide(2.7${\leq}k{\leq}3.0$) is Considerably lower than in thermal oxide.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.201-204
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• 2001

The tension levelling process is performed to elongate the strip plastically in combination of tensile and bending strain so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat shape. This paper is concerned with a simulation of the tension levelling process based on the analysis of the unit model for the tension leveller. Analysis technique such as the sequential analysis of the nit model is suggested and verified with the assembly analysis of the unit model for the effective and economic analysis of the full set of the tension leveller. Analysis of the full tension levelling process using sequential unit models is carried out and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1398-1400
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• 2002

A new PLF-BLU (Plastic Light Fiber-Back Light Unit) using side glowing light fiber rods array for the 42" LCD TV display has been evelopedd. The light fibers were 14mm in diameter and 50cm long pure transparent acrylic rods of 1.49 refractive index. Fine seratees were made on the flat side of rod. extremely bright incandscent light from lamp fed into the fiber si scattered at scratches then emerges through the surface of rod. A typical PLF-BLU system consists of 24 PLFs produced side glow of brightness of 4,500cd/㎡ to 6,500cd/㎡. New PLF-BLU is proved to be a BLU of rigid, bright, no heat generation, and low power consumption, hence a prospective BLU system for very and/or ultra large size TVs. A new LED-PLF-BLU system considered to be a revolutionary to break-through of the BLU technologies has also been developed, and is decribed briefly.

• ETRI Journal
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• 제26권5호
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• pp.443-451
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• 2004

Since the publication of Alamouti's famous space-time block code, various quasi-orthogonal space-time block codes (QSTBC) for multi-input multi-output (MIMO) fading channels for more than two transmit antennas have been proposed. It has been shown that these codes cannot achieve full diversity at full rate. In this paper, we present a simple feedback scheme for rich scattering (flat Rayleigh fading) MIMO channels that improves the coding gain and diversity of a QSTBC for 2$^n$ (n=3, 4, ${\cdots}$) transmit antennas. The relevant channel state information is sent back from the receiver to the transmitter quantized to one or two bits per code block. In this way, signal transmission with an improved coding gain and diversity near to the maximum diversity order is achieved. Such high diversity can be exploited with either a maximum-likelihood receiver or low-complexity zero-forcing receiver.