• Fire Science and Engineering
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• v.30 no.2
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• pp.75-80
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• 2016

In the wake of expanding and overpopulating urban areas, traffic congestion has been worsening increasingly, causing huge economic losses. In a bid to effectively use the space of metropolitan areas, the construction and operation of a double deck tunnel has been on the rise. On the other hand, a lower height of a double deck tunnel is expected to generate more smoke and soot in a fire than other usual tunnels. Therefore, it is undesirable to apply the standard for fire intensity or smoke generation, which were designed for existing road tunnels. A part of an effort to propose a design fire curve that is useful for double deck tunnel, is intended to obtain and analyze the fire characteristics in a double deck tunnel through a real scale fire test. The test was conducted according to the fire scenario with one passenger car and two passenger cars; the monitored fire intensity was a maximum of 2.4 MW and 3.5 MW, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.11-20
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• 2011

This study aimed to devise the method to construct safe and convenient bicycle road by considering the peripheral environmental factor related to using bicycle. Analyzing the existing design of bicycle road and construction case, this study established the method to design bicycle road that reflects site condition and presented the optimal design method for each type of bicycle road to construct safe and convenient bicycle road by analyzing the type of traffic accident for each type of bicycle road, surveying present situation and local survey. It was found that the optimum design of bicycle road for specification, width, curve radius, ascending slope, etc in consideration of peripheral environment and separating traffic between users of traffic means should be done by installing safety sign, safe facilities and separation facilities to design safe bicycle road. Further, the minimum traffic space of bicycle users and connection between bicycle roads should be ensured to design safe bicycle road. It is judged that information related to safety and convenience of bicycle road such as slope, route information, location of convenience facilities, information to the public traffic should be provided so as to activate the users of bicycle.

• Tunnel and Underground Space
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• v.10 no.2
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• pp.180-195
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• 2000

Grouting has been practiced as a reliable technique to improve the mechanical properties of rock mass. But, the study of ground improvement by greeting is rare especially in jointed rock mass. In this study, joint compression test and direct shear test were performed on pure rock joint and cement milk grouted rock joint to examine the grouting effect on the property of rock joint. In the pure rock joint compression test, joint closure varied non-linearly with normal stress. But after cement milk grouting, the normal deformation characteristics of the joint was linear at the low normal stress level. As normal stress increased. deformation of the sample rapidly increased due to the stress concentration at the joint asperities. Peak shear strength of the grouted joint in low normal stress was higher than that of non-grouted joint due to the cohesion, decreased exponetially as the grout thickness increased. Thus after cement milk grouting, the failure envelope modified to a curve that has cohesion due to grout material hydration with decreased friction angle. Shear stiffness and peak dilation angle of the grouted joint decreased as the grout thickness increased. The peak shear strength from the direct shear test on grouted rock joint was represented by an empirical equation as a fuction of grout thickness and roughness mean amplitude.

• Korean Journal of Remote Sensing
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• v.33 no.6_2
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• pp.1047-1060
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• 2017

In recent years, global warming has been continuing and abnormal weather phenomena are occurring frequently. Especially in the 21st century, the intensity and frequency of hydrological disasters are increasing due to the regional trend of water. Since the damage caused by disasters in urban areas is likely to be extreme, it is necessary to prepare a landslide susceptibility maps to predict and prepare the future damage. Therefore, in this study, we analyzed the landslide vulnerability using the logistic model and assessed the management plan after the landslide through the field survey. The landslide area was extracted from aerial photographs and interpretation of the field survey data at the time of the landslides by local government. Landslide-related factors were extracted topographical maps generated from aerial photographs and forest map. Logistic regression (LR) model has been used to identify areas where landslides are likely to occur in geographic information systems (GIS). A landslide susceptibility map was constructed by applying a LR model to a spatial database constructed through a total of 13 factors affecting landslides. The validation accuracy of 77.79% was derived by using the receiver operating characteristic (ROC) curve for the logistic model. In addition, a field investigation was performed to validate how landslides were managed after the landslide. The results of this study can provide a scientific basis for urban governments for policy recommendations on urban landslide management.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.137-145
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• 1992

Three-dimensional dose calculations based on CT images are fundamental to stereotactic radiosurgery for small intracranial tumor. In our stereotactic radiosurgery program, irradiations have been performed using the 6 MV photon beam of linear accelerator after stereotactic CT investigations of the target center through the beam's-eye view and the coordinates of BRW frame converted to that of radiosurgery. Also we can describe the tumor diameter and the shape in three dimensional configuration. Non-coplanar irradiation technique was developed that it consists of a combination of a moving field with a gantry angle of $140^{\circ}$, and a horizontal couch angle of $200^{\circ}C$ around the isocenter. In this radiosurgery technique, we provide the patient head setup in the base-ring holder and rotate around body axis. The total gantry moving range shows angle of 2520 degrees via two different types of gantry movement in a plane perpendicular to the axis of patient. The 3-D isodose curves overlapped to the tumor contours in screen and analytic dose profiles in calculation area were provided to calculate the thickness of $80\%$ of tumor center dose to $20\%$ of that. Furtheremore we provided the 3-D dose profiles in entire calculation plane. In this experiments, measured isodose curves in phantom irradiation have shown very similiar to that of computer generations.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.94-98
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• 2006

미계측 유역에 대한 정확한 수문반응을 예측하기 위해 수문반응 모의할 때 발생하는 불확실성을 예측하고 감소시킬 필요가 있다. 이러한 불확실성은 사용가능한 자료의 질과 양에 따라 달라지므로, 자료의 해상도는 수문반응 예측에서 중요한 요소가 된다. 그러므로 본 연구에서는 격자크기가 수문모형의 강우-유출응답모의에 어떠한 영향을 미치는지 살펴보았다. 격자크기가 입력데이터의 정보 손실을 발생시키지 않는 경우의 모형의 불확실성을 조사하기 위하여, 2차 및 3차 하천차수와 유역면적의 증가를 고려한 4가지 가상유역을 구성 하였다. 50m, 100m, 250m, 500m, 1000m의 격자를 사용하여 강우-유출모의를 수행하고, 격자에 따른 모의결과를 비교하기 위해 유출구의 수문곡선을 작성하였다. 또한, 소유역에서 하천으로 유입되는 단위길이당 유량과 하천의 합류점 전..후 및 유출구의 하천유량에 대한 Nash 계수를 산정하고 비교하였다. 기준이 된 격자크기와의 차가 큰 격자가 사용된 경우 모의된 수문반응의 차이는 증가하였고, 대상 유역의 면적이 커질수록, 하천차수가 작을수록 그 차이는 감소하였다. 소유역에서 하천으로 유입되는 단위폭당 유량의 오차는 흐름길이가 증가할수록 감소하였다. 흐름길이가 일정한 소유역으로만 구성된 가상유역 I, II에 대한 수문모의에서 하천유량의 오차는 하천을 따라 증가한 반면, 각기 다른 흐름길이의 소유역으로 구성된 가상유역 III, IV의 경우, 오차는 하천의 흐름에 따라 일정한 경향을 갖지 않고, 하천의 합류를 통해 증가되거나 감소하였다. 이 경우, 유역 유출구의 총체적 수문반응의 오차는 1차 하천의 합류후 발생한 최대오차보다 작았다.량을 산출하여 하천환경정비를 위한 기초자료로서 활용 될 수 있도록 하였다.구에 맞는 작물 생산 및 농촌관광단지 조성을 통해 부가가치증대 및 소득증대를 꾀함으로 농촌문제 해결에 도움이 될 것으로 기대된다. 본 연구를 통해 GIS 와 RS의 기술이 농촌분야에 더 효율적으로 적용될 것으로 기대되며, 농업기술센터를 통한 정보제공을 함으로써 대농민 서비스 및 농업기관의 위상이 제고 될 것으로 기대된다.여 전자파의 공간적인 가시화를 수행할 수 있었다. 본 전자파 시뮬레이션 기법이 실무에 이용될 경우, 일반인이 전자파의 분포에 대한 전문지식을 습득할 필요 없이, 검색하고자 하는 지역과 송전선, 전철 등 각종 전자파의 발생 공간 객체를 선택하여 실생활과 관련된 전자파 정보에 예측할 수 있어, 대민 환경정보 서비스 질의 개선측면에서 획기적인 계기를 마련할 것으로 사료된다.acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.2
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• pp.37-46
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• 2009

In this study, the seismic performance of the Buckling Restrained Knee Bracing (BRKB) system was evaluated through a pin-connected 1-bay 1-story frame. The BRKB system using a bolted channel section developed was composed of a steel plate as a load-resisting core member and two channel sections as a restrainment of the local and global buckling of the core plate. The main purpose of the BRKB system is to be used as an effective tool to re-strengthen/rehabilitate old low- and mid-rise RC frame buildings, which do not have enough seismic resistance to earthquake loadings. The main variables for the test specimens were the size of the core plates, stiffeners and the use of guide plates. The test results showed that the size of the core plate, which was the main element for the load-resisting member, was the most important parameter to achieve ductile behavior under tension as well as compression, until the maximum displacement exceed twice the design drift limit given by the AISC Seismic Provisions.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.157-168
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• 2009

The random utility theory and the multinomial logit model (including a more recent variant--the mixed multinomial logit) derived from it have constituted a back bone for theoretical and empirical analyses of various travel demand features including mode choice. In their empirical applications, however, it is customary to specify random utilities which are linear in modal attributes such as time and cost, and in socio-economic variables. The linearity helps easy derivation of important information such as value of travel time savings by calculating marginal rate of substitution between time and cost. In this paper the author focuses on the very linearity of the random utilities. Taking into account the fact that the mode chooser is also labour supplier, commodity consumer as well as leisure-seeker, the author sets up a maximization model of the traveller, which encompasses various economic activities of the traveller. The author derive from the model the indifference curve defined on the space of modal attributes, time and cost and investigate under what conditions the random utility of the traveller becomes linear. It turns out that there exist the conditions under which the random utility is really linear in modal attributes, but the property does not hold when the traveller has a corner solution on the space of modal attributes, or when the primary utility function of the traveller is directly affected by labour provided and/or the travel time itself. As a corollary of the analysis, a random utility is suggested, approximated up to the second order of the variables involved for empirical studies of the field.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.503-510
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• 2020

Eco-friendly mountain railways operate on concrete rack tracks embedded on existing sharp curved and steep roads to preserve the environment in mountainous areas. Owing to the narrow roads, single lines are inevitable, and many branches are required. In branches, previous switchers and heating devices cannot be applied, because of the limited spacing for the rack and the slow removal of thick ice. To solve these problems, a switch and a heating device have been developed. The switcher changes the line by moving the block of concrete track with hydraulic actuators. The lack of discontinuity reduces the derailment risk and makes locking simple. The heating device uses high frequency induction coils to increase the efficiency and melt the thick ice rapidly. The prototype switcher and heating device were produced and operated to prove their performance. The heating device yielded a 10 times greater efficiency than the previous one. The switcher and heating device are the essential core technologies for the operation of mountain trams in winter and contribute to the spread of mountain railways to domestic or foreign resort areas by enhancing safety and efficiency. In addition, they can provide transportation rights to local residents in poor winter traffic, and bring about tourism and local economic growth.

• Analytical Science and Technology
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• v.11 no.5
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• pp.409-412
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• 1998

The analytical method to determine europium(III) ion in aqueous solution by fluorescence spectroscopy based upon the conformational change of calmodulin in the presence of the analyte has been studied. The fiber optic chemical sensor used in this study was constructed by entrapping a fluorescein-labeled calmodulin solution, EGTA, buffer solution at the common end of a bifurcated fiber optic bundle by means of a dialysis membrane. The calibration curve to determine europium(III) ion was obtained when concentration of calmodulin, concentration of EGTA, Tris-HCl buffer solution, pH, excitation wavelength and fluorescence wavelength were $5.0{\times}10^{-5}M$, 0.50 mM, 5.0 mM, 7.0, 495 nm and 520 nm, respectively. The detection limit was $1.0{\times}10^{-11}M$ and the working range of the calibration curve for the sensor was $1.0{\times}10^{-11}M{\sim}1.0{\times}10^{-9}M$. The response time was 15 minutes. For the determination of europium(III) ion by the present method, $Na^+$ and $K^+$ ions did not interfere but $Ca^{2+}$ ion seriously interfered.