• Journal of Biosystems Engineering
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• 제8권2호
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• pp.62-68
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• 1983

This study was to examine the drying characteristics of barley and the effect of moisture content of barley on milling performance. A barley variety, Jogang, having 35.0% of initial moisture content was used for this experiment. Thermo-hydrostatic dryer which consists of blower, condensor, heater, humidifier, drying chamber and control box, etc., was used for the drying experiment. The change in the weight of a barley sample was continuously measured by means of the ring type load cell installed inside the drying chamber. Milling test runs the samples having the predetermined moisture content were taken from each drying test run. A laboratory type barley miller was used for the milling test. The results of the study are summarized as follows: 1. The drying constants (k) applied for the thin layer drying model, (M-Me)/(Mo-Me) = $Ae^{-kt}$ were 0.155, 0.259 and 0.548, respectively, at the three levels of drying temperatures, $40^{\circ}C$, $50^{\circ}C$ and $60^{\circ}C$. The drying constants complied with the Arrhenius Equation, K = Ko exp (-C/T), were determined as $Ko=1.901455{\times}10^8$ and C = 6563. 2. The laboratory milling test indicated that the highest milled and head barley recovery was resulted from the sample which was dryed at $40^{\circ}C$. In general, the increase in the drying temperature from $40^{\circ}C$ to $60^{\circ}C$ indicated a negative effect on milling yields. 3. Also, the sample having 15% M.C. presented the highest milled and head barley recovery among the five moisture content levels (12, 15, 18,21 and 24%).

• Parasites, Hosts and Diseases
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• 제51권4호
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• pp.441-448
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• 2013

This study describes the first record of Bourgelatia diducta (Nematoda: Chabertiidae) from wild boars in the Republic of Korea (=South Korea). Gastrointestinal tracts of 87 Korean wild boars (Sus scrofa coreanus) hunted in mountains in the south-western part of South Korea between 2009 and 2012 were examined for their visceral helminths. B. diducta, as identified by morphological characteristics of the head and tail, were recovered from the large intestine of 47 (54%) wild boars. The average length of adult female worms was $11.3{\pm}0.872$ mm and the thickest part of the body measured $0.54{\pm}0.04$ mm in maximum width, while those of males were $9.8{\pm}0.72$ and $0.45{\pm}0.03$ mm, respectively. The characteristic J-shaped type II ovejector was observed in females, and the type II dorsal ray with 2 rami on each side of the median fissure was uniquely seen in males. The buccal capsule was small, relatively thin-walled, cylindrical, very short, and ring-shaped. The externodorsal ray arose from a common stem with the dorsal ray. The cervical groove was absent. The anterior extremity was equipped with 20-22 external corona radiata, 4 cephalic papillae and 2 lateral amphids around the mouth. The eggs were $66.0{\times}38.9{\mu}m$ in average size. By the present study, B. diducta (Nematoda: Chabertiidae) is recorded for the first time in South Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic or taxonomic studies for strongylid nematodes related.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권12호
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• pp.761-767
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• 1999

Poly-Si TFTs(polycrystalline silicon thin film transistors) fabricated on a low cost glass substrate have attracted a considerable amount of attention for pixel elements and peripheral driving circuits in AMLCS(active matrix liquid crystal display). In order to apply poly-Si TFTs for high resolution AMLCD, a high operating frequency and reliable circuit performances are desired. A new poly-Si TFT with CLBT(counter doped lateral body terminal) is proposed and fabricated to suppress kink effects and to improve the device stability. And this proposed device with BC(buried channel) is fabricated to increase ON-current and operating frequency. Although the troublesome LDD structure is not used in the proposed device, a low OFF-current is successfully obtained by removing the minority carrier through the CLBT. We have measured the dynamic properties of the poly-Si TFT device and its circuit. The reliability of the TFTs and their circuits after AC stress are also discussed in our paper. Our experimental results show that the BC enables the device to have high mobility and switching frequency (33MHz at $V_{DD}$ = 15 V). The minority carrier elimination of the CLBT suppresses kink effects and makes for superb dynamic reliability of the CMOS circuit. We have analyzed the mechanism in order to see why the ring oscillators do not operate by analyzing AC stressed device characteristics.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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• pp.75-82
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• 2004

Many researcher's efforts have made a significant advancement of space frame structure with various portion, and it becomes the most outsanding one of space structures. However, with the characteristics of thin and long term of spacing, the unstable behavior of space structure is shown by initial imperfection, erection procedure or joint, especially space frame structure represents more. This kind of unstable problem could not be set up clearly and there is a huge difference between theory and experiment. Moreover, the discrete structure such as space frame has more complex solution, this it is not easy to derive the formulation of design about space structure. In this space frame structure, the character of rise-span ratio or load mode is represented by the instability of space frame structure with initial imperfection, and snap-through or bifurcation might be the main phenomenon. Therefore, in this study, space frame structure which has a lot of aesthetic effect and profitable for large space covering single layer is dealt. And because that the unstable behavior due to variation of inner force resistance in the elastic range is very important collapse mechanism, I would like to investigate unstable character as a nonlinear behavior with a geometric nonlinear. In order to study the instability. I derive tangent stiffness matrix using finite element method and with displacement incremental method perform nonlinear analysis of unit space structure, star dome and 3-ring star dome considering rise-span $ratio(\mu}$ and load $ratio(R_L)$ for analyzing unstable phenomenon.

• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.31-34
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• 2016

System In Package (SiP) is getting popular and momentum for the recent wearable, IoT and connectivity application apart from mobile phone. This is driven by market demands of cost competitive, lighter and smaller/thinner and higher performance. As one of many semiconducting assembly products, Leadframe product has been widely used for low cost solution, light/ small and thin form factor. But It has not been applied for SiP although Leadframe product has many advantages in cost, size and reliability performance. SiP is mostly based on laminate substrate and technically difficult on Leadframe substrate because of a limitation in SMT performance. In this paper, Leadframe based SiP product has been evaluated about key technical challenges in SMT performance and electrical shield technology. Mostly Leadframe is considered not available to apply EMI shield because of tie-bar around package edge. In order to overcome two major challenges, connection bars were deployed properly for SMT pad to pad and additional back-side etching was implemented after molding process to achieve electrical isolation from outer shield coating. This product was confirmed assembly workability as well as reliability.

• 센서학회지
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• 제20권3호
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• pp.172-177
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• 2011

Finger patients can't use their hands because of the paralysis their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by measuring the pressing force to be contacted with two fingers(thumb and first finger, thumb and middle finger, thumb and ring finger, thumb and little finger). At present, most hospitals have used a thin plastic-plate for measuring the two-finger grasping force, and we can only judge that they can grasp the plate with their two-finger through it, because the plate can't measure the two-finger grasping force. But, recently, the force measuring system for measuring two-finger grasping force was developed using three-axis force sensor, but it is very expensive, because it has a three-axis force sensor. In this paper, two-finger force measuring system with a one-axis force sensor which can measure two-finger grasping force was developed. The one-axis force sensor was designed and fabricated, and the force measuring device was designed and manufactured using DSP(Digital Signal Processing). Also, the grasping force test of men was performed using the developed two-finger force measuring system, it was confirmed that the grasping forces of men were different according to grasping methods, and the system can be used for measuring two-finger grasping force.

• 한국재료학회지
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• 제8권3호
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• pp.229-237
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• 1998

열적으로 이온화된 N과 증기상태의 Ga을 $300~730^{\circ}C$의 온도 범위에서 직접 반응시켜 (001)Si과 (00.1)사파이어 기판 위에 GaN박막의 성장 초기 단계에서는 GaN의 성장률이 증가한 후, 결정 핵을 중심으로 수평방향으로서 성장과 합체에 의하여 성장률의 변화가 일정 값에 달하였다. 이 연구에서 성장한 GaN박막에 대한 XPS분석 결과 낮은 온도에서 성장된 GaN박막은 진공 chamber 내의 산소가 성장된 박막 내에 많이 혼입 되어 있음을 알 수 있었다. 낮은 온도, 짧은 시간 동안 성장된 표면은 Ga덩어리들도 도포 되었다. 그러나, 기판온도와 성장시간이 증가함에 따라 이들은 피라미드 형태의 결정들로 성장된 후 원형고리 형태의 결정으로 합체되었다. 특히 N-소스의 공급이 충분한 경우에는 판상의 결정으로 성장되었다. 20K의 온도에서 측정된 PL스펙트럼에서는 3.32eV와 3.38eV에서 불순물과 관련된 발광이 관찰되었다.

• Journal of the Korean Wood Science and Technology
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• 제16권1호
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• pp.9-20
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• 1988

Lespedeza species have been widely used not only as plant resources for bark, leaves and honey, but also as erosion control materials. This study was carried out to investigate the structural and wood tiber characteristics in order to obtain basic information for the utilization of the wood. The wood structure was investigated for 10 selected species and the wood fiber, for the 5 selected species among Lespedeza species distributed all over the country. The following results were obtained. In the cross section, campylotropis showed ray diffuse porous wood, L. bicolor, L. cyrtobotrya, L. thunbergii var. intermedia, diffuse porous wood, and L. tomentella, L. angustifolioides. L. maritima, L. robusta, L. patentibicolor, ring porous wood. The maximum diameter of a single vessel ranged 66-123 ${\mu}$ in all species. Campylotropis showed the most number of vessels, L. angustifolioides, the least. The number of ray per mm ranged 7-22, Campylotropis showed the most number of rays, L. angustifolioides, the least. In the radial section the average length of vessel ranged 121-250 ${\mu}$ in all species. L. thunbergii var. intermedia showed the longest vessel, L. tomentella, the shortest. In tangential section the average width of the uniseriate ray ranged 9.2-14.7${\mu}$, that of the multiseriate ray, 19.2-42.1 ${\mu}$. The average height of the uniseriate ray ranged 143.0-1162.0 ${\mu}$. The width of fiber ranged 10.12-13.61 ${\mu}$, L. maximowiezii showed the narrowest tiber, L. thunbergii var. intermedia. the widest, the thickness of fiber wall ranged 2.93-3.71 ${\mu}$ in the five species. L. maximowiezii showed the most thin fiber wall, L. thunbergii var. intermedia, the thickest, L. cyrtobotrya showed the difference in the size of fiber between the shade and the sunny sites but L. maximowiezii showed no difference. There was significant difference in fiber length, fiber width and wall thickness between L. eyrtobotrya and L. maximowiezii.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.105-105
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• 2000

현재 급격히발전하는 이동통신기술로 미루어 보아 앞으로는 모든 정보통신이 무선통신으로 이루어질 것이다. 그런데 무선통신은 이동성과 대용량의 정보전송에 초점을 맞추어 발전하고 있다. 많은 정보량을 전달하기 위해서 현재 사용되는 주파수 대역보다 고주파의 전파가 사용되어야 한다. 또한 이동성을 향상시키기 위해서는 통신기기의 소형화를 이루어야 하고 그러기 위해서 궁극적으로 모든 소자를 하나의 칩(chip)으로 집적화하는 것이 필요하다. 따라서 벌크상태로 사용되고 있는 유전체 공진기를 소형화, 즉 박막화해야만 한다. 결국 유전체 박막의 마이크로파 대역에서의 유전특성을 연구하고 그 특성을 향상시켜야만 한다. 통신기기에서 사용되는 유전체 공진기는 소형화를 위해 높은 유전율과 낮은 유전손실(tan$\delta$), 즉 높은 품질계수 (Q)를 가져야 한다. 마이크로파 대역에서 사용되고 있는 유전체 중에서 TiO2는 벌크 상태의 rutile 상에서 100정도의 높은 유전율과, 4 GHz에서 10,000 정도의 높은 품질계수를 나타낸다고 보고되어 있다. 따라서 본 연궁서는 TiO2 박막의 마이크로파 유전특성을 연구하였고 anatase 박막의 유전특성도 측정하였다. TiO2 박막을 RF magnetron reactive sputtering 방법으로 Ar (15 sccm)과 O2 (1.5 sccm) 기체를 사용하여 상온에서 증착하였다. 4mTorr의 증착압력에서 안정한 rutile 박막을 얻었고, 15 mTorrdo서 준안정한 anatase 박막을 얻을 수 있었다. 그리고 그 중간의 압력에서 두 상이 혼합된 박막이 증착되었다. 위와 같은 방법으로 형성한 TiO2 박막의 마이크로파 유전특성을 측정하기 위해 마이크로스트립 링공진기 (microstrip ring resonator)를 제작하였다. 마이크로스트립 링 공진기는 링의 원주길이가 전자기파 파장길이의 정수배가 되면 공진이 일어나는 구조이다. Fused quartz를 기판으로 하여 증착압력을 변수로 하여 TiO2 박막을 증착하였다. 그리고 그 위에 은 (silver)을 사용하여 링 패턴을 형성하였다. 이와 같이 공진기를 제작하여 network analyzer (HP 8510C)로 마이크로파 대역에서의 공진특서을 측정하였다. 공진특성으로부터 전체 품질계수와 유효유전율, 그리고 TiO2 박막의 품질계수를 얻어내었다. 측정결과 rutile에서 anatase로 박막의 상이 변할수록 유전율은 감소하고 유전손실은 증가하는 결과를 나타내었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.435-435
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• 2010

A inclined slot-excited plasma source is newly designed and constructed for higher flux HNB(Hyperthermal Neutral Beam) generation. The present source is different from the vertical SLAN(SLot ANtenna) sources [1] in two aspects. One is that the slots are inclined, and the other is that the magnetic field is configured to a cusp type. These modifications are intended to make the source plasma operated in sub-milli-torr pressure regime and as thin as possible, both of which is to get higher HNB flux by decreasing the re-ionization rate of the reflected atoms from the neutralizer [2]. The plasma is generated in a quartz tube of internal diameter 170 mm enclosed in a aluminum application chamber of larger diameter 250 mm. The microwave power is fed to the plasma chamber by 8 inclined slots cut into the application chamber wall. The slots are coupled the chamber to a WR280 waveguide wound around it to form a ring resonator. In order to make two slots $\lambda_g/2$ apart in phase, the adjacent slots are rotated in opposite directions. The rotation angle of the slots are set to $60^{\circ}$ from the chamber axis. Between the quartz chamber and the aluminum cylindrical chamber 8 NdFeB magnets are equally spaced and fixed to form the cusp magnetic field confinement and ECR (Electron Cyclotron Resonance) field. In this presentation, the magnetic and electromagnetic simulations, and the measured plasma parameters are given for both the inclined and the vertical slot-excited plasma sources. We also discuss how the sources can be tailored to suit better-performing HNB sources.