Earticle

음향 도플러 유속계(Acoustic Doppler Current Profiler, ADCPs)는 하천의 유량측정에 널리 사용되고 있으나, 유량 측정성과의 불확도를 평가하는 방법에 대하여 진행된 연구는 부족한 현실이며, 이는 실제 하천에서 유속 및 유량 등의 수리량을 조절하는 것이 현실적으로 불가능하여 ADCP의 불확도 요인별 실험 및 분석이 어렵기 때문이다. 유량 및 수리량의 측정 불확도를 평가하기 위하여 과학 및 공학 분야에서는 다양한 연구들이 진행되어 왔으며, 그 중 국제적으로 공인받고 있는 방법 중 하나가 GUM (Guide to the Expression of Uncertainty Measurement)이다. 본 연구에서는 GUM 표준안을 기반으로 ADCP의 유량 측정 불확도를 평가하기 위한 연구를 수행하였다. ADCP의 유량 측정 불확도 요인별 분석을 수행하기 위하여 유량 공급의 조절이 가능한 실 규모 수로를 보유하고 있는 하천실험센터에서 실험을 진행하였으며, ADCP의 측정 정확도에 영향을 미치는 수심, 측정 지점에서 하안까지의 거리, ADCP의 잠김 깊이, 유속 오차, 측정 시간, 반복 횟수, 하상 조건 등에 대한 측정 정확도 평가 실험을 수행하였다. ADCP로 유량을 측정하는 방법은 지점측정방식을 기반으로 유속-면적법을 통해 산정하는 방법과 일반적으로 사용되는 이동측정방식이 있으며, 본 연구에서는 ADCP의 지점측정방식을 통해 유량을 산정하는 Section-by-Section 방법으로 산정된 유량의 불확도를 평가하였다. 모든 측정 결과는 요인별 불확도 평가를 수행하기 위하여 유속은 ADV, 수심은 광파기로 측정된 결과와 비교하였다.

Acoustic Doppler Current Profilers (ADCPs) have been widely utilized for assessing streamflow discharge, yet few comprehensive studies were conducted to evaluate discharge uncertainty in consideration of individual uncertainty components. It could be mostly because it was not easy to determine which uncertainty framework can be appropriate to rigorously analyze streamflow discharge driven by ADCPs. In this regard, considerable efforts have been made by scientific and engineering societies to develop a standardized theoretical framework for uncertainty analysis in hydrometry. One of the well-established UA methodology based on sound statistical and engineering concepts is Guide to the Expression of Uncertainty Measurement (GUM) adopted widely by various scientific and research communities. This research fundamentally adapted the GUM framework to assess individual uncertainty components of ADCP discharge measurements, and subsequently provided results of a customized experiment in a controllable real-scale artificial river channel. We focused particularly upon sensitivities of uncertainty components in the GUM framework driven by ADCPs direct measurements such as depths, edge distance, submerged depth, velocity gap, sampling time, repeatability, bed roughness and so on. Section-by-Section method for ADCP discharge measurement was applied for uncertainty analysis for this study. All of measurements were carefully compared with data using other instrumentations such as ADV to evaluate individual uncertainty components.

In this study, due to the buckling of steel structures in the absence of rapid degradation and consequent strength steel members without causing the destruction of the stable behavior of the proposed method to produce test specimens for the compression tests were performed. The purpose of this study is the development of FLD(Force Limiting Device) to prevent a member buckling for a slender member. Further, the behavior of steel structures with FLD would be stable by high energy absorption capacity.

Reinforced concrete structures are often required repair and strengthening because of various external factors. Recently, fiber reinforced polymer or plastic (FRP) in the form of sheet or plate is often used in repair and strengthening RC structures. Many of previous researches have conducted theoretical examinations and experiments on repair and strengthening with FRP and supplied materials necessary in construction sites, but few of them are about the effects of strengthening quantities on the strengthening effect. Thus, this study purposed to analyze through experiment, the flexural strengthening effect of section increment method using carbon fiber reinforced polymer(CFRP) strengthening RC structures.

교토대학 원자로실험소의 46-MeV 전자선형가속구를 이용하여 $^{99}Tc$의 중성자포획단면적을 중성자에너지 0.007 eV에서 47 keV에 걸쳐 중성자 비행시간법을 이용하여 측정을 하였다. 이 중성자포획 결과는 $^{10}B(n,\gamma)$반응의 중성자 반응 단면적에 상대적으로 얻어졌다. 얻어진 결과를 확인하기 위해서 교토대학 원자로실험소의 납감속장치를 이용한 결과를 확인하였다. TOF방법으로 얻어진 결과는 0.0253 eV에서의 결과(20.01 b)에 규격화되었다. 기존의 실험결과들과 평가결과들인 ENDF/B-VI, JENDL-3.2, and JEF-2.2은 본 연구에서 TOF와 납감속장치로 얻어진 결과들과 비교 및 검토하였다.

The neutron capture cross section of $^{99}Tc$ has been measured relative to the $^{10}B(n,\gamma)$ standard cross section by the neutron time-of-flight(TOF) method in the energy range of 0.007 eV to 47 keV using a 46-MeV electron linear accelerator(linac) at the Research Reactor. Institute, Kyoto University(KURRI). In order to experimentally prove the result obtained, the supplementary cross section measurement has been made from 0.3 eV to 1 keV using the Kyoto University Lead stowing-down spectrometer (KULS) coupling to the linac. The relative measurement by the TOF method has been normalized to the reference value(20.01 b) at 0.0253 eV and the KULS measurement to that by the TOF method. The existing experimental data and the evaluated capture cross sections in ENDF/B-VI, JENDL-3.2, and JEF-2.2 have been compared with the current measurements by the linac TOF and the KULS experiments.

본 연구는 의료 시뮬레이션에서 절개 및 봉합과 같은 위상 변화를 효과적으로 처리하기 위한 볼륨 변형 가시화를 개 선하는 방법을 제안한다. 병렬 리샘플링을 적용하여 실시간 고해상도 볼륨 변형이 가능하다. 본 연구는 병렬 리샘플 링 기법 적용 시 단면에서 발생하는 노이즈에 주목하여 노이즈의 발생 원인을 분석하고, 노이즈를 줄이기 위한 두 가지 방법을 제안한다. 우선, 볼륨 가시화시 그라디언트 계산에서 오차가 발생하는 것에 착안하여 전체 탐색 마스크 를 이용하는 방법을 제안하고, 이어서 더 효율적인 십자 마스크를 제안하여 단면 영역을 검출하고 조명 연산에서의 오류를 방지한다. 실험 결과, 제안된 방법은 단면에서의 화질이 개선됨을 확인하였고, 십자 마스크는 전체 탐색 마 스크에 비해 효율적인 연산이 가능한 것으로 나타났다.

This study proposes an improved volumetric deformation visualization method to effectively handle topological changes, such as cutting and suturing, in medical simulations. By applying a parallel resampling technique, real-time high-resolution volumetric deformation is achieved. This research focuses on the noise that occurs in cross-sections during parallel resampling and analyzes its causes. To reduce this noise, two methods are proposed. First, recognizing errors in gradient calculations during volume rendering, a full-search mask method is introduced. Then, a more efficient crossmask method is proposed to detect cross-section regions and prevent errors in lighting calculations. Experimental results confirm that the proposed methods enhance cross-sectional image quality, and the cross-mask method demonstrates higher computational efficiency compared to the full-search mask method.

본 연구의 목적은 2007 개정 국어과 교육과정에 따른 여러 검정 교과서 의 학습활동을 분석하여 효율적인 비언어적 의사소통을 교육을 위한 방안 을 연구하는 데 있다. 먼저 Ⅱ장에서는 교과서의 학습활동을 분석하기 위한 기준을 설정할 것 이다. 이를 위하여 비언어적 의사소통의 특성과 유형을 살펴보고, 2007 개 정 국어과 교육과정의 특성과 말하기 영역의 내용 체계 및 말하기 영역의 성취 기준을 검토하여 분석의 기준을 제시할 것이다. Ⅲ장에서는 Ⅱ장에서 설정한 네 가지의 분석기준을 바탕으로 각 검정 교 과서의 학습활동을 분석할 것이다. 현 교과서에서 비언어적 의사소통을 지 도하는 데 문제가 되는 부분을 지적하여 Ⅳ장에서 제시할 개선 방안의 기 초를 마련할 것이다. Ⅳ장에서는 Ⅱ장과 Ⅲ장의 내용을 바탕으로 비언어적 의사소통을 효과적 으로 교육할 수 있는 방안을 교육과정의 측면과 교과서의 측면에서 살펴볼 것이다. Ⅴ장에서는 앞으로 개정될 교육과정과 새로 나올 교과서에서 앞서 살펴 본 개선 방안을 반영하여 효과적인 비언어적 의사소통의 교육이 이루어지 기를 전망해 볼 것이다.

The purpose of this study is to research efficient methods for teaching non-verbal communication skills according to the 2007 revised Language Arts curriculum. It is based on an analysis of learning activities in several textbooks. Chapter two sets up a standard to analyze the learning activities in textbooks. It will examine the types and characteristics of non-verbal communication. A standard of analysis will also be suggested to review characteristics of the speech section in the 2007 revised Language Arts curriculum. Chapter three will analyze each textbook's learning activities based on four standards set up in chapter two. Current textbooks do not teach non-verbal communication skills properly, so improvements will be recommended in the next chapter. Chapter four, looks at effective ways to teach non-verbal communication through the curriculums and textbooks examined in chapters two and three. Chapter five, looks forward to the expected improvements that can result from the suggested changes.

$^{237}Np$ is very important material in the fission products of nuclear reactors. Resonance integral(RI) tests of this material is necessary to check between the experiments and the evaluated data. Such feedback to the evaluated data is very important to correct data and improve of codes. The RI for the $^{237}Np(n,{\gamma})^{238}Np$ reaction were measured by using the 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University (KURRI). The measurement was performed in the energy region from 0.005 eV and 10 keV. RI obtained as 804.7 barns, compared with those of the evaluated data in JENDL-4.0 and Mughabghab.

PURPOSE. Adequate passive-fitting of one-piece cast 3-element implant-supported frameworks is hard to achieve. This short communication aims to present an alternative method for section of one-piece cast frameworks and for casting implant-supported frameworks. MATERIALS AND METHODS. Three-unit implant-supported nickel-chromium (Ni-Cr) frameworks were tested for vertical misfit (n = 6). The frameworks were cast as one-piece (Group A) and later transversally sectioned through a diagonal axis (Group B) and compared to frameworks that were cast diagonally separated (Group C). All separated frameworks were laser welded. Only one side of the frameworks was screwed. RESULTS. The results on the tightened side were significantly lower in Group C ($6.43{\pm}3.24{\mu}m$) when compared to Groups A ($16.50{\pm}7.55{\mu}m$) and B ($16.27{\pm}1.71{\mu}m$) ($P$ <.05). On the opposite side, the diagonal section of the one-piece castings for laser welding showed significant improvement in the levels of misfit of the frameworks (Group A, $58.66{\pm}14.30{\mu}m$; Group B, $39.48{\pm}12.03{\mu}m$; Group C, $23.13{\pm}8.24{\mu}m$) ($P$ <.05). CONCLUSION. Casting diagonally sectioned frameworks lowers the misfit levels. Lower misfit levels for the frameworks can be achieved by diagonally sectioning one-piece frameworks.

In this paper, an integrated fault section detection and isolation strategy is proposed based on the application of the Distribution Automation System(DAS) utilizing advanced IT and communication technologies. The Feeder Remote Terminal Unit(FRTU) has been widely used to collect data in the Korean distribution system. The achieved data is adopted in this method for detecting multiple fault types. Especially in the case of single phase-to-ground fault, the fault section is detected by comparison of the zero-sequence current phase angle. The test results have verified the effectiveness of the proposed method in a radial distribution system through extensive simulations in Matlab/Simulink. Furthermore, a communication-based demo system identical to the simulation model has been developed, and it can be applied as an online monitoring and control program for fault section detection and isolation.

Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

Panel methods are useful tools for analyzing fluid-flow around a wing section. It has the advantage of fast and accurate calculation, compared to other CFD Methods such as RANS solvers. This paper suggests a piecewise linear panel method in order to improve accuracy of existing panel methods by changing the piecewise constant singularity strength to linear singularity strength(for dipole strength). The piecewise linear panel method adopts the linear distribution of singularity strength, while control point is located at the node of each panel. Formulation of the piecewise linear panel method is given, and some calculation results are shown for typical wing sections.

Panel methods are useful tools for analyzing fluid-flow around a wing section. It has the advantage of fast and accurate calculation, compared to other CFD Methods such as RANS solvers. This paper suggests a piecewise linear panel method in order to improve accuracy of existing panel methods by changing the piecewise constant singularity strength to linear singularity strength(for dipole strength). The piecewise linear panel method adopts the linear distribution of singularity strength, while control point is located at the node of each panel. Formulation of the piecewise linear panel method is given, and some calculation results are shown for typical wing sections.

최근 대도시에서는 교통량 증가 등으로 인해 대심도 터널 건설의 필요성이 날로 증대되고 있어서, 대심도 복층터널의 분기에 대한 연구가 필요한 실정이다. 때문에 본 연구에서는 FLAC 2D 프로그램을 이용하여 지반의 종류, 측압계수, 보강방법, 토피고를 매개변수로 선정하여 민감도 분석을 실시하였다. 궁극적으로 터널 분기부에서 최적의 분기부 형상 및 보강방법을 찾고자 하였다. 본 연구결과 일반적인 생각과 달리 박스형 확폭단면이 아치형보다 안정성이 높게 나타났다. 이는 아치형 굴착면적이 박스형보다 약 30% 정도 넓었기 때문인 것으로 판단된다. 또한 지반이 좋지 않은 경우는 록볼트 보강보다 강관그라우팅 보강 시의 안정성이 더 높았으며, 강관그라우팅의 보강두께와 범위는 확폭부의 안정성에 큰 영향을 끼치지 못하였다.

Recently, the necessity of deep and double-deck tunnels has been grown day by day due to the increase of traffic volume at metropolitans and thus the study on the divergence of those tunnels becomes required. Therefore sensitivity analyses were conducted with FLAC 2D program by selecting ground condition, coefficient of lateral pressure, support pattern, and depth of rock cover as parameters. Ultimately, this study is to find the optimal shape and support method of a diverged section. As the results of this study, it turned out that the box type gave higher stability of the section than arch type unlike the general thought. It can be explained that the arch type has about 30% bigger excavation area than the box type. When the ground conditions are poor, steel pipe grouting reinforcement gives higher stability than rockbolt reinforcement, but its thickness and range do not give a great influence on the stability of the enlarged section.

Panel methods are essential tools for analyzing a fluid-flow problem around complex three dimensional bodies, but they lack ability to solve viscous effects. On the other hand, CFD methods are considered as powerful tools for analyzing fluid-flow characteristics including viscosity. However, they also have short falls, requiring more computing time and showing different results depending on the selection of turbulence models and grid systems. In this paper a hybrid scheme combining a panel method and a CFD method is suggested. The scheme adopts a panel method for far-field solution where viscous effects are negligible and a CFD method for the solution of RANS equations in near-field where viscous effects are relatively strong. The intermediate region between the far-field and near-field is introduced where the calculated field point velocities by the panel method are given as boundary velocities for the CFD method. To verify the scheme, calculated results, by a panel method, a CFD method and the hybrid scheme, for a two dimensional foil section are compared. The suggested hybrid scheme gives reasonable results, while computation time and memory can be dramatically reduced. By using the hybrid scheme efforts can be concentrated for the local flow near the leading and trailing edges, by providing more dense grid system, where detailed flow characteristics are required.

The paper proposes a method of constructing the three-dimensional CAD model from digitized cloud-of­points data of the human body, thereby automatically extracting several featured dimensions. The main steps are; segmentation, sectioning, fairing and surface approximation. In segmentation process the input three-dimensional set of points are grouped into each functional part of the human body by searching the boundary points when being viewed from a certain direction. The next step slices the grouped points to obtain section curves which will be faired (smoothed) by the difference-fairing method. Each faired section curve (a set of points) is approximated to the NURBS form by use of well known method, from which we can construct a NURBS surface. The parametric surfaces for functional parts of a human body are interrogated to extract several featured dimensions of a human body.

전 지구적 기후변화에 따른 돌발성 집중호우의 증가와 급격한 도시화로 인해 도시홍수의 위험성이 증가하고 있으며 침수로 인한 인명 및 재산피해가 급증하고 있다. 특히 중·소규모 도시하천은 대부분 홍수유출 도달시간이 매우 짧고 수위가 급격히 상승하는 특성이 있어 집중호우에 매우 취약하여 더욱 선제적이고 정확한 홍수 예·경보가 요구된다. 현재 중·소규모 도시하천의 경우 실시간 하천수위가 위험수위에 도달할 시 하천을 통제하고 위험경보를 발령하는 방식으로 대응하고 있지만, 둔치 침수에 이르는 시간이 매우 짧아 통제가 어려우며 이마저도 행정 자치구별로 예경보 운영 및 통제기준이 상이하여 실질적인 대응에 한계가 있다. 따라서 본 연구는 강우 발생 시부터 즉각적 대응을 위해 강우-수위 관계 및 상류 돌발홍수와 강우강도의 영향을 분석하여 구간별 둔치 범람 기준을 제시하고 자치구별로 상이한 예경보 수위 기준을 통합하여 산정하는 방법을 개발하였다. 본 연구는 서울시의 주요 침수취약지구인 도림천을 대상으로 수행하였으며, 도시하천 특성의 내외수를 연계한 강우-유출모형(SWMM)을 이용하여 확률강우 시나리오에 따른 대상하천의 수위변화 및 도달시간을 분석하였다. 본 연구의 성과는 중, 소규모 도시하천에의 홍수예경보시스템 구축 및 효율적인 하천방재계획 수립에 기여할 것으로 기대된다.

The underground method can be divided into Top-Down, Semi-Top-Down, Up-Up and Down-Up methods according to the construction order of the upper and lower structures. Among them, the Down-Up method proceeds with the construction of the first floor and its lower floors, and when the foundation is completed, the vertical members of the basement are sequentially completed from the foundation and the above-ground floor is constructed. In this paper, the crack reduction method around the open section of the Down-Up method affected by earth pressure was analyzed and divided into design and construction parts.

Optimum cross-sectional shape of an automotive disc brake was developed based on FEM thermal analyses and the Taguchi method. Frictional heat flux and convection heat transfer coefficients were first calculated using equations and applied to the disc to calculate accurate temperature distribution and thermal deformations under realistic braking conditions. Maximum stress was generated in an area with highest temperature under pads and near the hat of ventilated disc and vanes. The SN ratio from Taguchi method and MINITAB was applied to obtain the optimum cross-sectional design of a disc brake on the basis of thermal deformations. The optimum cross-section of a disc can reduce thermal deformation by 15.2 % compared to the initial design.

교통시설의 성능개선과 신규 건설로 인하여 지상 및 지하에서의 교통시설의 병행 및 교차가 빈번하게 발생한다. 특히, 도심지 확대로 대심도 도로, 지하철, 철도 등의 건설을 위하여 수평굴착(근접시공) 공사가 시공되어야 한다. 이러한 굴착공사에 의하여 상부 지반 또는 시설물에서는 침하와변형이 발생하며, 이 피해를 최소화하는 방안이 필요하다. 현재 저토피 구간 굴착공사시 지반이완과 굴착 상부지반의 초기침하 억제를 효율적으로 제어하기 위하여 지반내 응력 변형을 최소화할수 있도록 소구경 강관 또는 강판을 이용한 공법(Super Equilibrium Method ; SEM)을 개발하고 있다. 본 연구에서는 이 공법에서 요구되는 구성요소별 성능을 수치해석을 통하여 검토하였다. 이를위하여 무처리 상태에서의 SEM 공법의 특성을 평가하여 순수 지반 응력 변화를 확인하고, SEM 구성요소(SEM 파일, SEM 플레이트)별 요구사양을 정의하였다. 이후 SEM 공법의 구성요소에 대하여 재료, 강성, 길이, 설치각도 등 변화에 따른 성능평가를 검토하여 SEM 공법 개발을 위한 최적설계단면을 검토하였다.

Due to the improvement of the performance of the traffic facilities and the construction of the new facilities, traffic facilities in the ground and underground are frequently accompanied and crossed. In particular, horizontal drilling works will be carried out for the construction of roads, subways, railways, etc. in the urban areas. Such excavation works will cause settlement and deformation in the upper ground or facilities and it is necessary to minimize the damage. In this study, we developed a super equilibrium method (SEM) that can effectively suppress the settlement and the initial settlement of the excavation upper ground during low - to - highway excavation. This method uses small diameter steel tubes or steel plates. The performance of each component required by this method was studied through numerical analysis. For this purpose, the characteristics of the SEM method in the untreated state were evaluated and the change of the pure ground stress was confirmed. And we defined requirements for each component(SEM file, SEM plate). The performance of the SEM method was evaluated by changing the material, stiffness, length, and installation angle. Finally, optimal design section for SEM method could be suggested.