• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.763-771
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• 2010

The rapid increase of wildlife passage installation since the late 2000s was aimed to reduce roadkill caused by habitat fragmentation and losses related to road construction, but wildlife-vehicle collisions are now still occurred even near the wildlife passage area. This is the reason that the effectiveness of wildlife passage have not been evaluated in combination with absence of monitoring data and management strategy of the wildlife passage. The AHP method are used, in this study, to identify the evaluation factors affecting the effectiveness of the present 367 wildlife passages in a mitigation measures to reduce road effects on wildlife species. Ten evaluation factors are derived from third levels in the AHP analysis. Priority setting to identify appropriate management strategies in first level is selected among four second levels on facility, environment, wildlife species and management tool. The AHP analysis suggested that neighboring environments are the most important factor at the second level, and passage structure, harmony with natural surroundings, wildlife occurrence and monitoring of the passage are also important factors at the third levels. In summary, effective measurements of wildlife passage management is based on managing the passage with neighboring topography and natural surrounding. This is useful to establish wildlife passage management strategy in order to reduce the negative effects of roads on wildlife species.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.2
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• pp.189-198
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• 2004

We consider the problem of whether the three-dimensional checkerboard has the connectivity. For this purpose, we first consider the problem of determining the effective conductivity of a checkerboard-shaped composite material by the Brownian motion simulation method. Specifically, we use the efficient first-passage-time technique. Simulation results show that the effective conductivity of the three-dimensional checkerboard increases faster than the two-dimensional counterpart as the contrast between the phase conductivities increases. This implies that the three-dimensional checkerboard's connectivity is stronger than the two-dimensional checkerboard's and thus each phase material of the three-dimensional checkerboard is more likely to be connected than not to be connected.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.9
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• pp.1249-1259
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• 2002

The present study investigates the convective heat/mass transfer inside a cooling passage of rotating gas-turbine blades. The rotating duct has various configurations made of ribs with 70。 attack angle, which are attached on leading and trailing surfaces. A naphthalene sublimation technique is employed to determine detailed local heat transfer coefficients using the heat and mass transfer analogy. The present experiments employ two-surface heating conditions in the rotating duct because the surfaces, exposed to hot gas stream, are pressure and suction side surfaces in the middle passages of an actual gas-turbine blade. In the stationary conditions, the parallel rib arrangement presents higher heat/mass transfer characteristics in the first pass, however, these characteristics disappear in the second pass due to the turning effects. In the rotating conditions, the cross rib present less heat/mass transfer discrepancy between the leading and the trailing surfaces in the first pass. In the second pass, the heat/mass transfer characteristics are much more complex due to the combined effects of the angled ribs, the sharp fuming and the rotation.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.79-79
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• 1993

The retrospective analysis of 285 cases with diagnoses of foreign bodies in the food and air passages that were managed at the Department of Otolaryngology, KangNam St.Mary's Hospital from Nov.1980 to Oct.1992 are reported. The results are as follows : 1) Among 285 cases, 254 cases(89.2%) were lodged in the esophagus and 31 cases (10.8%) in the air passage. The ratio between the foreign bodies in the food and those in the air passage was about 8.2 : 1 2) Among all cases, 171 cases were males(59.8%) and 114 cases were females(40.2%). 3) The group under 5 years old having foreign bodies was over half of all cases(56.5%), and the group over 51 years old was 15.5% of all cases. 4) The incidence of foreign bodies in order of frequency was coin(35.6%), fish bone (21.8%) and chicken bone(7.9%) in the food passage. Beans and peanuts were the most common foreign bodies in the air passage. 5) In the location of foreign bodies of the food passage, 208 cases(82.2%) were found in the first esophageal narrowing. In the air passage, the frequent sites of lodgement were the bronchus, trachea and larynx in order. 6) The 67.0% of all cases was removed within 24 hours. The duration of lodgement showed differences in relation with varieties of the foreign bodies.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.305-318
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• 2012

Although the existing performance-based design method for the vertical breakwater evaluates an average sliding distance during an arbitrary time, it does not calculate the probability of the first occurrence of an event exceeding an allowable sliding distance(i.e. the first-passage probability). Designers need information about the probability that the structure is damaged for the first time for not only design but also maintenance and operation of the structure. Therefore, in this study, a time-dependent reliability design method based on a stochastic process is developed to evaluate the first-passage probability of caisson sliding. Caisson sliding can be formulated by the Poisson spike process because both occurrence time and intensity of severe waves causing caisson sliding are random processes. The occurrence rate of severe waves is expressed as a function of the distribution function of sliding distance and mean occurrence rate of severe waves. These values simulated by a performance-based design method are expressed as multivariate regression functions of design variables. As a result, because the distribution function of sliding distance and the mean occurrence rate of severe waves are expressed as functions of significant wave height, caisson width, and water depth, the first-passage probability of caisson sliding can be easily evaluated.

• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.140-149
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• 2007

This study investigated the thoughts of undergraduate students in Seoul about the birth rites and wedding ceremony and their foods. Among 524 students who were surveyed, 299 students answered that the meaning of the first birthday rites was for special memory, followed by the child's future and family's harmonies. 248 desired birth rites to remain unchanged and 150 desired extravagance and waste to be reduced. Regarding wedding ceremony, 328 answered that changes are necessary in wedding ceremony gifts. Next, process in wedding ceremony and bridegroom's gift box should be changed, Most of the students didn't know clearly the foods of the one hundredth birthday and the first birthday; nevertheless they considered the birth rites to be necessary. Regarding wedding ceremony, half of the students knew the process and half didn't. Two hundred students answered they knew ordinarily about the foods of wedding ceremony. There were no significant differences in hometown about foods of wedding ceremony. In parent's religions, there were no differences about gifts & foods offered by the bride. The Buddhist students knew well about the birth rites' foods and considered birth rites to be necessary. The correlation of parents' work and student's major and passage rites showed that professional parents knew well about birth rites' foods but religious believers didn't know well. Students majoring in natural science were not concerned with birth rites and thought that they were unnecessary and they didn't know about wedding ceremony process and foods. Knowledge about birth rites increased with increasing number of siblings. Large families were interested in birth rites and knew well about the wedding process, wedding ceremony foods and gift & foods offered by the bride.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.6.3-6
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• 1983

A total of 287 patients with foreign body in the air and food passage was treated in our unit between 1972 and 1982 and the following results were obtained : 1) The ratio between food and air passage was about 8 : 1. 2) The most common foreign bodies in the esophagus were coin (55.8%) and bone (28.5 %). Beans were the most common in the air passage (39.4%). 3) In sex distribution, there was no significant difference between male and females in the esophageal foreign bodies, but in the air passage male were prevalent (M : F = 57.9% : 42.1%). 4) In the age incidence, 61.8 % of the esophageal foreign bodies and 71 % of the foreign bodies in the air passage were under 5 Years of age. 5) The most prevalent site of Lodgement in the esophagus was the first narrowing (82.3 %). In the air passage, bronchial foreign bodies were more common and the right bronchus was the more frequent site (2 : 1). 6) In duration of lodgement, 62.2 % of esophageal foreign bodies and 55.2 % of foreign bodies in the air passage were removed within one day. 7) The most common complication of foreign bodies in the air passage was pneumonia (55.5%). 8) The removal of the foreign bodies in the air passage was performed by ventilation - bronchoscopy (84.3%). Two of 38 cases expired.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.227-231
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• 2007

We improve Wilehemski-Fixmann theory for intrachain reaction dynamics of a polymer chain by taking into account excluded volume effects between reactive groups in the polymerchain. An approximate analytic expression for the intra-chain reaction dynamics is obtained for Gaussian chain model and compared to Brownian dynamics simulation results. The results of the present theory are in a better agreement to Brownian dynamics simulation results than those calculated by previously reported theories.

• Proceedings of the Korean Statistical Society Conference
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• 2000.11a
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• pp.57-64
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• 2000

In this paper we consider a Markovian perfect debugging model for which the software failure is caused by two types of faults, one which is easily detected and the other which is difficult to detect. When a failure occurs, a perfect debugging is immediately performed and consequently one fault is reduced from fault contents. We also treat the debugging time as a variable to develop a new debugging model. Several measures, including the distribution of first passage time to the specified number of removed faults, are also obtained using the proposed debugging model, Numerical examples are provided for illustrative purposes.

• Journal of the Korean Statistical Society
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• v.24 no.1
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• pp.141-147
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• 1995

A diffusion model for a system subject to random shocks is introduced. It is assumed that the state of system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. It is also assumed that the shocks coming to the system according to a Poisson process decrease the state of the system by a random amount. It is further assumed that a repairman arrives according to another Poisson process and repairs or replaces the system i the system, when he arrives, is in state zero. A forward differential equation is obtained for the distribution function of X(t), the state of the systme at time t, some boundary conditions are discussed, and several interesting characteristics are derived, such as the first passage time to state zero, F(0,t), the probability of the system being in state zero at time t, and F(0), the limit of F(0,t) as t tends to infinity.