• Journal of Ship and Ocean Technology
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• 제3권1호
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• pp.12-26
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• 1999

A new concept of collision energy absorbing system for ;he New Oil-tankers with Advanced Double Hull Structure(NOAHS and NOAHS II) are presented through the joint-research pro-gran between Inha and Hamburg-Harburg University. A comparative study on col vision resistance of these proposed side structures with standard double hull structure of 310K DWT class VLCC, is carried out. The fatigue investigation of structural detail parts is also included. It contains a comparative fatigue study based on pertinent regulations of Classification Societies.

• 센서학회지
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• 제30권2호
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• pp.82-87
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• 2021

In this paper, we propose a high-speed, low-power complementary metal-oxide semiconductor (CMOS) binary image sensor featuring a gate/body-tied (GBT) p-channel metal-oxide-semiconductor field-effect transistor (PMOSFET)-type photodetector based on a double-tail comparator. The GBT photodetector forms a structure in which the floating gate (n+ polysilicon) and body of the PMOSFET are tied, and amplifies the photocurrent generated by incident light. The double-tail comparator compares the output signal of a pixel against a reference voltage and returns a binary signal, and it exhibits improved power consumption and processing speed compared with those of a conventional two-stage comparator. The proposed sensor has the advantages of a high signal processing speed and low power consumption. The proposed CMOS binary image sensor was designed and fabricated using a standard 0.18 ㎛ CMOS process.

• 한국정보통신학회논문지
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• 제17권2호
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• pp.461-466
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• 2013

사회가 고도의 디지털 정보화 시대로 발전함에 따라 영상복원 등 디지털 영상처리 기술분야에 관한 많은 연구가 진행되고 있다. 임펄스 잡음에 훼손된 영상을 복원하는데 대표적인 방법은 SM(Standard Median) 필터가 있지만, SM 필터는 에지영역에서 오류를 나타내어 영상의 품질을 저하시킨다. 본 논문에서는 임펄스 잡음환경에서 훼손된 영상을 복원하기 위해 화소를 중심으로 하여 이중 마스크를 취하는 변형된 메디안 필터 알고리즘을 제안하였다. 이중 마스크를 취함에 따라 제안한 방법은 우수한 잡음제거 및 에지보존 특성을 나타내었고 영상의 화질을 개선하였다.

• 한국환경보건학회지
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• 제21권4호
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• pp.56-62
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• 1995

Recently, the traffic noise around residences and schools has become a serious social problem with the increase of the amount of transportation. This study was performed to investigate the sound proof efficiency of windows for traffic noise. The results were as follows 1) The traffic noise in 19 sites among 22 sampling sites was higher value than 65 dB(A) being roadside environment standard level in the daytime when all windows were opened, while the noise in 22 sampling sites was transmitted below standard level when all windows were closed. 2) The transmission loss of sound level at single window and double windows were 10~25 dB(A) and 11~29 dB(A) respectively. 3) The transmission loss of sound level at sampled school with sound proof pannel was 7~8 dB (A), which was lower 2~7 dB(A) than the theoretical value of the influence assessment . 4) The construction cost of double windows was lower 28% even if include the cost of setting up air conditioner for the summer season and the power consuming cost for its operation than that of sound proof pannel for traffic noise. 5) The effect of transmission loss of windows was more influenced by airtight than materials of windows.

• Korea-Australia Rheology Journal
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• 제19권3호
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• pp.141-146
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• 2007

We examine the wall contact of a $3\;{\mu}m$ tethered DNA chain's free end under shear with a focus on developing schemes for double-tethering in the application of making scaffolds for molecular wires. At this scale our results are found to be highly dependent on small length scale rigidity. Chain-end-wall contact frequency, mean fractional extension deficit upon contact, and standard deviation in extension upon contact are examined for scaling with dimensionless flow strength, Wi. Predictions made using a one dimensional approximation to the Smoluchowski equation for a dumbbell and three dimensional dumbbell simulations produce extension deficit, standard deviation, and frequency scaling exponents of -1/3, -1/3, and 2/3, respectively whereas more fine-grained Kratky-Porod (KP) simulations produce scaling exponents of -0.48, -0.42, and 0.76. The contact frequency scaling of 2/3 is derived from the known results regarding cyclic dynamics Analytical scaling predictions are in agreement with those previously proposed for ${\lambda}-DNA$. [Ladoux and Doyle, 2000, Doyle et al., 2000]. Our results suggest that the differences between the dumbbell and the KP model are associated with the addition of chain discretization and the correct bending potential in the latter. These scaling results will aide future exploration in double tethering of DNA to a surface.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.406-412
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• 2018

In this paper, we propose a narrow resonant waveguide probe that can improve the measurement sensitivity in near-field scanning microwave microscopy. The probe consists of a metal waveguide incorporating the following two sections: a straight section at the tip of the probe whose cross-section is a double-ridged rectangle, and whose height is much smaller than the waveguide width; and a standard waveguide section. The advantage of the narrow waveguide is the same as that of the quarter-wave transformer section i.e., it achieves impedance-matching between the sample under test (SUT) and the standard waveguide. The design procedure used for the probe is presented in detail and the performance of the designed resonant probe is evaluated theoretically by using an equivalent circuit. The calculated results are compared with those obtained using the finite element method (Ansoft HFSS), and consistency between the results is demonstrated. Furthermore, the performance of the fabricated resonant probe is evaluated experimentally. At X-band frequencies, we have measured the one-dimensional scanning reflection coefficient of the SUT using the probe. The sensitivity of the proposed resonant probe is improved by more than two times as compared to a conventional waveguide cavity type probe.

• 국제초고층학회논문집
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• 제11권4호
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• pp.265-276
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• 2022

Double-Skin Facades (DSF) on tall buildings are becoming increasingly common in urban environments due to their ability to provide architectural merit, passive design, acoustic control and even improved structural efficiency. This study aims to understand the effects of porous DSF on the aerodynamic characteristics of tall buildings using wind tunnel tests. High Frequency Force Balance and pressure tests were performed on the CAARC standard tall building model with a variable porous DSF on the windward face. The introduction of a porous DSF did not adversely affect the overall mean forces and moments experienced by the building, with few differences compared to the standard tall building model. There was also minimal variation between the results for the three porosities tested: 50%, 65% and 80%. The presence of a full-height porous DSF was shown to effectively reduce the mean and fluctuating wind pressure on the side face of the building by about 10%, and a porous DSF over the lower half height of the building was almost as effective. This indicates that the porous DSF could be used to reduce the design load on cladding and fixtures on the side faces of tall buildings, where most damage to facades typically occurs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1138-1142
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• 2010

High speed railway structure, contact of vehicle needs to design considering the running stability(dynamic behavior). Also, upper structure has to satisfy design standard about moving load, high speed train(KTX). So, the high speed railway structure has to satisfy the requirement of natural frequency, vertical acceleration on deck, face distortion and vertical displacement considering ride comfort, which is suggested Ho-nam high speed railway design standard. In this study, it was investigated and evaluated to the dynamic behavior for a double-rib arch railway bridge subjected to moving load considering real high speed train loads.

• 기술표준
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• 통권12호
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• pp.67-78
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• 2003

In order to keep a characteristic corrugated fibreboard of fruits and flowers, temperature and humidity change of corrugated fibreboard are analyzed. According to relative humidity rises at fixed temperature, bursting strength of corrugated fibreboard was fallen and double wall corrugated fibreboard appeared greatly the bursting strength decline rate than double faced corrugated fibreboard and edgewise compressive strength of paper more than humidity 80% in rapidly fall. A column crush test of paper became decrease in the high temperature and ordinary temperature strength did over humidity 70% rapidly fallen and strength decrease happened by low temperature 80% slowly fallen and later rapidly. According to ISO standard temperature humidity conditioning (23$\pm$2 , 50$\pm$2%) change, pulp composition difference as to the ring crush strength of a physical strength and generally compare to KS standard increased 5∼8% for the compressive strength, and wet strength reagent was increased 4% inside and out.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.35-36
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• 2007

We report a probe using a single double clad fiber (DCF) for fluorescence spectroscopy. Bidirectional separate transmission for excitation and fluorescence light in a single fiber was implemented. A DCF coupler made by side-polished method could extract none but the collected fluorescence signals propagating in inner cladding mode, thereby diminishing the interference of silica background generated by the excitation in core mode. The experimental results show that the fluorescence spectra of biological tissues obtained using the DCF probes have much less silica background than using a standard multiple-mode fiber.