• Journal of the Optical Society of Korea
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• 제19권2호
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• pp.169-174
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• 2015

Muscle vibration measurement has long been an unique scientific study, in general, and the direct reaction of animals to feel pain (algesia), either from vascular or muscle contraction, is a complex perceptual experience. Thus this paper proposes a way to measure animal algesia quantitatively, by measuring the changes in muscle vibration due to a pinprick on the surface of the skin of a Spodoptera litura larva. Using the laser optical triangulation measurement principle, along with a CMOS image sensor, linear laser, software analysis, and other tools, we quantify the subtle object point displacement, with a precision of up to $10{\mu}m$, for our chosen Spodoptera litura larva animal model, in which it is not easy to identify the tiny changes in muscle contraction dynamics with the naked eye. We inject different concentrations of formalin reagent (empty needle, 12% formalin, and 37% formalin) to obtain a variety of different muscle vibration frequencies as the experimental results. Because of the high concentrations of reagent applied, we see a high frequency shift of muscle vibration, which can be presented as pain indices, so that the algesia can be quantified.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.445-446
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• 2010

Gen-2 Q-알고리즘에서는 질의 라운드 동안 사용할 슬롯-카운트 매개변수인 $Q_{fp}$에 대한 초기 값이 정의되어 있지 않다. 이 경우, 만일 초기 $Q_{fp}$ 값이 아주 큰 경우에는 초기 질의 라운드 동안 빈 슬롯이 많이 발생할 수 있고, 반면 초기 $Q_{fp}$ 값이 아주 적은 경우에는 충돌이 많이 발생할 수 있다. 이로 인하여 질의 라운드 동안 최적의 프레임 크기에 수렴하는 속도가 늦어질 수 있으므로 식별 속도 및 효율이 저하되는 문제점이 발생할 것으로 예상된다. 따라서 본 논문에서는 초기 슬롯 카운트의 값이 Gen-2 Q-알고리즘의 성능에 미치는 영향을 분석한다.

• Computers and Concrete
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• 제20권6호
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• pp.655-661
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• 2017

Fiber reinforced concretes exhibit higher tensile strength depending on the percent and type of the fiber used. These concretes are used to reduce cracks and improve concrete behavior. The use of these fibers increases the production costs and reduces the compressive strength to a certain extent. Therefore, the use of fiber reinforced concrete in regions where higher tensile strength is required can cut costs and improve the overall structural strength. The behavior of fiber reinforced concrete and normal concrete adjacent to each other was investigated in the present study. The concrete used was self-compacting and did not require vibration. The samples had 0, 1, 2 and 4 wt% polypropylene fibers. 15 cm sample cubes were subjected to uniaxial loads to investigate their compressive strength. Fiber Self-Compacting Concrete was poured in the mold up to 0, 30, 50, 70 and 100 percent of the mold height, and then Self-Compacting Concrete without fiber was added to the empty section of that mold. In order to investigate concrete behavior under bending moment, concrete beam samples with similar conditions were prepared and subjected to the three-point bending flexural test. The results revealed that normal Self-Compacting Concrete and Fiber Self-Compacting Concrete may be used in adjacent to each other in structures and structural members. Moreover, no separation was observed at the interface of Fiber Self-Compacting Concrete and Self-Compacting Concrete, either in the cubic samples under compression or in the concrete beams under bending moment.

• Wind and Structures
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• 제31권6호
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• pp.495-508
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• 2020

To investigate the structural behaviour of grouped tanks under wind loads, 2 problems need to be figured out, wind pressures on tank shells and critical loads of the shell under these pressure distribution patterns. Following the wind tunnel tests described in the companion paper, this paper firstly seeks to obtain wind loads on the external wall in a squarely-arranged cylindrical tank group by numerical simulation, considering various layouts. The outcomes demonstrate that the numerical method can provide similar results on wind pressures and better insights on grouping effects through extracted streamlines. Then, geometrically nonlinear analyses are performed using several selected potentially unfavourable wind pressure distributions. It is found that the critical load is controlled by limit point buckling when the tank is empty while excessive deformations when the tank is full. In particular, significant reductions of wind resistance are found on grouped full tanks compared to the isolated tank, considering both serviceability and ultimate limit state, which should receive special attention if the tank is expected to resist severe wind loads with the increase of liquid level.

• 대한전자공학회논문지
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• 제24권1호
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• pp.102-109
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• 1987

This study is carrier out to investigate the carrier injection and the characteristics of trapping for the CVD deposited Al2O3 film on Si substrates. Samples used are metal -Al2O3-Si Structure in which metal field plates are used with Aluminium or God. Canier injection and trapping, which result in flat band voltalge shift, occur at fields as low as 1~2 MV/cm. An approximate method is proposed for computing the location of the centroid of the trapped electrons in this paper. Results show that carriers are trapped near the injecting interface at fields less than about 5MV/cm. Because of continued charging, a steady state can not be reached. Therefore the unique I-V curve is obtained when the traps are initially empty. By utilization of applied voltage on each point of the fresh device sample, it is measured the I-V surves for two polarities of applied voltage. The current densities observed in the Al2O3 films are much larger than those obtained in SiO2.

• 한국인터넷방송통신학회논문지
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• 제23권6호
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• pp.139-143
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• 2023

본 논문에서는 CT영상을 구성하는 RT 알고리즘에 비해 원추형 CB-CT 시스템에서 이용할 수 있는 TPSM 알고리즘을 적용하여 기존의 RT보다 빠르게 3D CT 영상 구성을 할 수 있도록 하였으며 두 개의 알고리즘에 대한 영상속도를 비교분석 하였다. 이를 위하여 원추형 CB-CT 시스템에서 이용할 수 있는 TPSM 알고리즘을 적용하여 3D CT 영상구성에 있어서 실시간 처리가 가능하도록 하였다. 실험결과 TPSM을 이용하여 구성된 단면 영상은 중심점에서 멀어질수록 빈 화소에 의해 영상의 질이 미소하게 감소하지만 TPSM 회전 기반법의 경우에서 영상 구성 속도는 RT알고리즘보다 월등하게 우수하다는 것을 알 수 있었다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2011년도 춘계학술발표대회 논문집
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• pp.153-158
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• 2011

According to the change of life environment and economic growth, the more city has highly developed, the more concentrated urban function. That is, city is required for adding infra structure. But, both of limited land resources and financial problems made it impossible to add infra structure. So, the necessity of multi-dimensional planning of urban infra structure was recognized. Especially, In Urban residential area, in order to secure parking area, It is on the increase that mixed-use of the playground of school in the high density area and the empty space of park. School and park is closely connected with town community, playing a central role on town life. For this reason, they are highly demanded for providing space in the urban residential area and also expected to be effective. However, people using park and school are almost young students and the elderly, it needs to consider not only the parking convenience also the safety of users in design process. In this study, we analysed the physical characteristics and the utilization of mixed-use of school and park. and then evaluated the case in the point of convenience and safety. For this, first we selected the case among the sites constructed in seoul, and divided 2type of 'slope type' and 'flatland type'. The meaning of this study is to suggest elementary standards for design in the point of multi-dimensional land use planning.

• 인지과학
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• 제29권1호
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• pp.1-16
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• 2018

본 연구에서 얼굴형 인공지능 스피커에 대한 선호도와 신뢰도가 나이에 따라 어떻게 달라지는지 살펴보았다. 인공지능 스피커의 외형은 성별(남녀)과 나이(20/60대) 네 가지 범주에서 로봇 얼굴과 사람 얼굴이 7단계로 혼합되어 제시되었다. 참여자들 역시 이 네 가지 범주에 맞춰 모집되었고, 각 범주의 얼굴 자극에 대한 호감도와 신뢰도를 7점 척도로 평가하였다. 연구 결과, 인공지능 스피커의 외형이 사람 얼굴을 닮을수록 노인들은 호감도와 신뢰도를 높게 평가했지만, 청년들은 로봇 얼굴과 사람 얼굴이 중간 정도 섞인 형태를 가장 선호하고 신뢰하여 전체적으로 뒤집힌 U자 형태의 평가를 보였다. 네 가지 얼굴 범주에서 선호도를 평가했을 때, 참여자들은 나이와 성별과 관계없이 젊은 얼굴이 가장 높은 점수를 받았다. 그런데, 이모티콘 얼굴과 얼굴이 없이 비어있는 조건을 추가하여 물었을 때, 여전히 노인들은 사람 얼굴을 가장 선호했지만, 청년들은 상대적으로 이모티콘 얼굴과 비어있는 조건을 더 선호하였다. 종합하면, 인공지능 스피커 맥락에서, 노인들은 청년들보다 로봇 얼굴이 아닌 사람 얼굴에 높은 수용적 태도를 보였다. 홀로 사는 노인 인구가 증가하는 미래에 인공지능 스피커의 역할이 중요해짐에 따라, 노인들을 위한 인공지능 스피커의 디자인과 개발에서 본 연구 결과가 좋은 참고가 될 것으로 기대된다.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.106-111
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• 2017

본 연구에서는 해양구조물의 상부(top side) 구조물을 설치할 때 필요한 장치인 LMU(Leg Mating Unit)의 강성을 구조해석을 통하여 검토하였다. 이것은 구조물의 지지 점에 장착되어 설치 시 충격을 흡수하고 안정적으로 구조물을 지지하는 데 사용된다. LMU는 가운데가 비어있는 원통형 구조로서 수직 하중을 지지하기 위해서 일래스토머릭 베어링(Elastomeric Bearing, 이하 EB)과 철판을 여러 층으로 적층한다. EB의 강성은 기본적으로 베어링의 크기에 영향을 받지만, 동일한 크기에서도 내부 보강판의 적층 수에 따라 강성이 변하게 된다. 일반적으로 보강판과 압축 강성 사이의 관계를 분석하여 적합한 설계를 한다. EB의 강성은 변위를 제어하면서 반력을 산출하는 방식으로 분석을 한다. 먼저 보강판의 크기와 압축 강성 관계를 검토하고, 보강판의 적층 수와 압축 강성 관계를 검토한다. LMU는 장착되는 지점마다 다른 하중이 요구된다. 해석을 통해 각 지점에서 동일한 변형이 발생하도록 압축 강성을 다르게 설계하는 것이 목표이다. 본 연구의 유한요소해석을 위하여 상용 프로그램인 ANSYS를 이용하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.218-218
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• 2012

Recently, hexagonal manganites have attracted much attention because of the coexistence of ferroelectricity and antiferromagnetic (AFM) order. The crystal structure of hexagonal manganites consists of $MnO_5$ polyhedra in which $Mn^{3+}$ ion is surrounded by three oxygen atoms in plane and two apical oxygen ions. The Mn ions within Mn-O plane form a triangular lattice and couple the spins through the AFM superexchange interaction. Due to incomplete AFM coupling between neighboring Mn ions in the triangular lattice, the system forms a geometrically-frustrated magnetic state. Among hexagonal manganites, $YMnO_3$, in particular, is the best known experimentally since the f states are empty. In addition, for applications, $YMnO_3$ thin films have been known as promising candidates for non-volatile ferroelectric random access memories. However, $YMnO_3$ has low magnetic order temperature (~70 K) and A-type AFM structure, which hinders its applications. We have synthesized $YMn1_{-x}Cr_xO_3$ (x = 0, 0.05 and 0.1) samples by the conventional solid-state reaction. The powders of stoichiometric proportions were mixed, and calcined at $900^{\circ}C$ for $YMn1_{-x}Cr_xO_3$ for 24 h. The obtained powders were ground, and pressed into 5-mm-thick disks of 1/2-inch diameter. The disks were directly put into the oven, and heated up to $1,300^{\circ}C$ and sintered in air for 24 h. The phase of samples was checked at room temperature by powder x-ray diffraction using a Rigaku Miniflex diffractometer with Cu $K{\alpha}$ radiation. All the magnetization measurements were carried out with a superconducting quantum-interference-device magnetometer. Our experiments point out that the Cr-doped samples show the characteristics of a spin-glass state at low temperatures.