• Economic and Environmental Geology
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• v.46 no.4
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• pp.301-312
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• 2013

Landslides are caused by complex interaction among a large number of interrelated factors such as topography, geology, forest and soils. In this study, a comparative study was carried out using fuzzy relationship method and artificial neural network to evaluate landslide susceptibility. For landslide susceptibility mapping, maps of the landslide occurrence locations, slope angle, aspect, curvature, lithology, soil drainage, soil depth, soil texture, forest type, forest age, forest diameter and forest density were constructed from the spatial data sets. In fuzzy relation analysis, the membership values for each category of thematic layers have been determined using the cosine amplitude method. Then the integration of different thematic layers to produce landslide susceptibility map was performed by Cartesian product operation. In artificial neural network analysis, the relative weight values for causative factors were determined by back propagation algorithm. Landslide susceptibility maps prepared by two approaches were validated by ROC(Receiver Operating Characteristic) curve and AUC(Area Under the Curve). Based on the validation results, both approaches show excellent performance to predict the landslide susceptibility but the performance of the artificial neural network was superior in this study area.

• Fire Science and Engineering
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• v.23 no.4
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• pp.32-39
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• 2009

In this study, 18 plots were selected for particular investigation on Gangneung area and Samcheok area and Uljin area, where forest fire was occurred after thinning in 2007. After selection, a relationship between a damage of forest fire and thinning were compared and analyzed. Many factor such as a damaged species, a thinning or non-thinning, a direction of forest fire head, DBH, a height of tree, a mortality of tree, a leeward scorching ratio, a crown damage ratio, a forest tree standing crop density, a crown base height, a leaving of thinning slash, a location of plot (GPS), elevation, an aspect of slope, an angle of slope, and a topography were measured. Therefore, we analyzed a relationship with forest fire. In the result of this analysis, it was founded that the leeward scorching ratio was 24.7% on thinning area whereas 60.2% on non-thinning area. Subsequently, leeward scorching ratio on thinning area was increased by about 35.5% more than on non-thinning area. In the result of analysis about tree species, a forest of pine tree was more damaged than forest of oak tree. The mortality of tree was increased by about 41.4% on non-thinning area. When stands were close to thinning slashes, these were more damaged by 10${\sim}$20% than other stands for increasing of amount of a combustion material. Especially, as potential of re-ignition increased for more cumulated thinning slash, it will be more important to require a method for a periodical removing or practical utilization of slash.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.1-23
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• 1979

The use of barley seeder attached to rotary tiller in the rural area has a significant meaning not only for the solution of labor peak season, but also for the increase of land utilization efficiency. The facts that presently being used barley seeders are all based on the mechanical principles of the reverse rotation, center drive and are all using forward rotating tine, which is used to be easily and heavily worn out when it rotates reversely, raise problem of recommending them to rural area in Korea. Therefore, the main objective of the study was to develop new type of rotary tine attachable to barley seeders. To attain the objective the following approaches were applied. (1) The kinematic analysis of reverse rotating barley seeders. (2) The studies on the soil bin and artificial soil. (3) The comparative experiment on the power requirement of prototype tine. The results obtained from the studies are summarized as follow: 1. The kinematic analysis of barley seeder attached to rotary tiller: The following results were obtained from the kinematic analysis for deriving general formulae of the motion and velocity characterizing the rotary tine of barley seeders presently being used by farmers. a) The position vector (P) of edge point (P) in the rotary tine of reverse rotating, center drive was obtained by the following formula. $$P=(vt+Rcos wt)i+Rsin wt j+ \{ Rcos \theta r sin \alpha cos (wt- \beta +\theta r) +Rsin \theta r sin \alpha sin (wt-\beta + \theta r) \} lk $$ b) The velocity of edge point $(P^')$ of reverse rotating, center drive rotary tine was obtained by the following formula. $$(P^')=(V-wR sin wt)i+(w\cdot Rcoswt)j + \{ -w\cdot Rcos \theta r\cdot sin \alpha \cdot sin (wt-\beta +\theta r) + w\cdot Rsin \theta r\cdot sin \alpha \cdot cos (wt- \beta + \theta r \} k $$ c) In order to reduce the power requirement of rotary tine, the angle between holder and edge point was desired to be reduced. d) In order to reduce the power requirement, the edge point of rotary tine should be moved from the angle at the begining of cutting to center line of machine, and the additional cutting width should be also reduced. 2. The studies on the soil bin and artificial soil: In order to measure the power requirement of various cutting tines under the same physical condition of soil, the indoor experiments Viere conducted by filling soil bin with artificially made soil similar to the common paddy soil and the results were as follows: a) When the rolling frequencies$(x)$ of the artificial soil were increased, the densIty$(Y)$ was also increased as follows: $$y=1.073200 +0.070780x - 0.002263x^2 (g/cm^3)$$ b) The absolute hardness $(Y)$ of soil had following relationship with the rolling frequencies$(x)$ and were increased as the rolling frequencies were increased. $$Y=37.74 - \frac {0.64 + 0.17x-0. 0054x^2} {(3.36-0.17x + 0.0054x^2)^3} (kg/cm^3)$$ c) The density of soil had significant effect on the cohesion and angle of internal friction of soil. For instance, the soil with density of 1.6 to 1.75 had equivalent density of sandy loam soil with 29.5% of natural soil moisture content. d) The coefficient of kinetiic friction of iron plate on artificial soil was 0.31 to 0.41 and was comparable with that of the natural soil. e) When the pulling speed of soil bin was the 2nd forward speed of power tiller, the rpm of driving shaft of rotary was similar to that of power tiller, soil bin apparatus is indicating the good indoor tester. 3. The comparative experiment on the power requirement of prototype tine of reverse rotating rotary: According to the preliminary test of rotary tine developed with various degrees of angle between holder and edge pcint due to the kinematic analysis, comparative test between prototype rotary tine with $30 ^\circ $ and $10 ^\circ$ of it and presently being used rotary tine was carried out 2nd the results were as follows: a) The total cutting torque was low when the angle between holder and edge point was reduced. b) $\theta r$ (angle between holder and edge point) of rotary tine seemed to be one: of the factors maximizing the increase of torque. c) As the angle between holder and edge point ($\theta r$) of rotary tine was $30 ^\circ $ rather than $45 ^\circ $, the angle of rotation during cutting soil was reduced and the total cutting torque was accordingly reduced about 10%, and the reduction efficiency of total cutting torque was low when the angle between holder and edge point ($\theta r$) of rotary tine was $10 ^\circ $, which indicates that the proper angle between holder and edge point of rotary tine should be larger than $10 ^\circ $ and smaller than $30 ^\circ $ . From above results, it could be concluded that the use of the prototype rotary tine which reduced the angle between holder and edge point to $30 ^\circ $, insted of $45 ^\circ $, is disirable not only decreasing the power requirements, but also increasing the durabie hour of it. Also forward researches are needed, WIlich determine the optimum tilted angle of rotary brocket, and rearrangement of the rotary tine on the rotary boss.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.111-118
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• 2009

In modern Asia major cities had same problem with lack of affordable housing for families. So they had to concentrate to the mass supply of housing and made some physical counter effects like high density of cities, limitation of parking space. Also people who lived in those cities could suffer from broken traditional community culture. To rebuild traditional community and increase land usage, Block housing is suggested as a new kind of multi-family housing for old town redevelopment. Now some governments are trying to make urban code to give some initiative for new block housing development in old city blocks. They expect this new housing type can help to solve serious problems like lack of parking area, green space and context of block. Also they hope that block housing development can help to increase safety of town and reduce cost of development. The purpose of this study is to review the establishment and development process of Block Housing and to confirm the aspect which has been changed with urban organization together. Also this study tried to find out the intentional characteristics of similarities and differences with comparison of Korea and Japan. And as a result we could find critical physical viewpoint, and provide considerations for future study and plan. Several cases of block housing in Korea and Japan were reviewed for comparative study and Post Occupancy Evaluation (POE) survey was examined to find satisfaction factors and problems which were expected to improved.

• Journal of Oriental Neuropsychiatry
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• v.7 no.1
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• pp.15-37
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• 1996

This thesis investigates 220 female students ranging from 19 to 26 years old attending universities in the Wonju area to determine the correlations between mental health and the density of serum iron . According to their serum iron levels, they were divided into three groups and analyzed with the GARS Scale Assessment and the THI Test Assessment. The results are as follows;1. On the comprehensive GARS Scale tests, for all groups, task, occupation and levels of university-related frustration(1) marked the highest scores.2. On the comparative assessment of each group's GARS Scale scores, Group A showed higher stress perception in terms of personal relationship(2,3) than any orther groups. 3. On the comprehensive THI test scores coverring all groups, Multiple subjective symptoms(I) marked the highest scores. 4. On the comparative assessment of each group's THI test scores, Group A showed higher Multiple subjective symptoms(I) and Irregularities of life(G) than any orther groups.5. Comparing and analyzing the GARS Scale Assessment and the THI Test, we found that Group A showed high stress perception, which may cause psychosomatic diseases such as 'yu zheng(鬱證;melancholia). With those results, we can see that the contant of serum iron is correlated to stress perception and the condition of mental health. In the future studies using the GARS Scale and the THI Test, it will be necessary to examine more subject groups in terms of multi-aspects and to investigate the standard group in more detail.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.6
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• pp.1219-1228
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• 2015

The Fixed Area ARFs (Area Reduction Factors) method has limitations in providing exact information about spatial distribution due to the lack of enough density of rain gauge stations. In this study the storm-centered ARF was evaluated between frontal and typhoon storm events utilizing radar precipitation. In estimating storm-centered ARFs, in order to consider the horizontal advection, direction, and spatial distribution of rain cells, the rotational angle of rainfall of each rainfall event and the optimum areal rainfall within the spatial rain cell envelope was taken into account. Compared with the frontal storm, the ARF of typhoon storm shows narrow range of variability. It is noted that the ARFs of frontal storm increases with the rainfall duration, but those of typhoon storm shows opposite pattern. As a result the typhoon ARFs appear greater than frontal ARFs for 1~3 hours of duration, but less for more than 6 hours of duration.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.29-39
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• 2023

In the recent period, there have been numerous earthquakes both domestically and internationally, and buildings in South Korea are particularly vulnerable to seismic design and earthquake damage. Therefore, the objective of this study is to discover an effective method for assessing the seismic vulnerability of buildings and conducting a density analysis of high-risk structures. The aim is to model this approach and validate it using data from pilot area(Seoul). To achieve this, two modeling techniques were employed, of which the predictive accuracy of the statistical analysis technique was 87%. Among the machine learning techniques, Random Forest Model exhibited the highest predictive accuracy, and the accuracy of the model on the Test Set was determined to be 97.1%. As a result of the analysis, the district rating revealed that Gwangjin-gu and Songpa-gu were relatively at higher risk, and the density analysis of at-risk buildings predicted that Seocho-gu, Gwanak-gu, and Gangseo-gu were relatively at higher risk. Finally, the result of the statistical analysis technique was predicted as more dangerous than those of the machine learning technique. However, considering that about 18.9% of the buildings in Seoul are designed to withstand the Seismic intensity of 6.5 (MMI), which is the standard for seismic-resistant design in South Korea, the result of the machine learning technique was predicted to be more accurate. The current research is limited in that it only considers buildings without taking into account factors such as population density, police stations, and fire stations. Considering these limitations in future studies would lead to more comprehensive and valuable research.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.1
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• pp.15-32
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• 1986

Today, the control and criteria of design for apartment site are heavily dependent on laws and ordinance in Korea. But they are indefinite and some part which are deficient in laws and ordinance, are dependent on professional judgement. So trey are not consistent and there are many problems in their applications. The purpose of this study is to suggest fundamental date for the future establishment of better control and criteria, by way of evaluation method about existing control and criteria of design in apartment site in the country. The method of this study is reviewing the present laws and ordinance, carrying out the questionaire survey and making a comparative analysis by doing various statistical analyses. The results of this are as follows; 1) More definite criteria of site density are necessary. 2) Stricter criteria and control about the orientation are indispensible for more efficient use of site. 3) More diverse facilities must be provided. 4) The laws and ordinance must be strengthened for the purpose of increasing the landscape area. 5) It is desirable to provide the criteria of bicycle road to save energy. 6) The facilities criteria for the physically handicapped must be strengthened. 7) The mechanism for the reflection of habitant's attitudes and beliefs should be established. 8) It's necessary to simplify the permission procedure to save tilde and money.

• Applied Microscopy
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• v.27 no.4
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• pp.417-432
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• 1997

The structures of the fertilized egg envelope in three species of cichlidae, golden severum (Cichlasoma severum var.), convic cichlid (Cichlasoma nigrofasciatum) and discus (Symphysodon aequifasciatus) were investigated by routine light and electron microscopies. The fertilized eggs of all three species were of the non-transparent, ellipsoidal, adhesive and non-floted type. The egg envelopes have a single micropyle, which is thought to the pathway of sperm in the area of the animal pole. In golden severum, an outer surface of egg envelope was covered by a reticular layer, that of convic cichlid was covered by an amorphous reticular layer and that of discus was covered by a branched reticular layer. The fertilized egg envelopes consisted of two distinct layers, an adhesive outer layer and an inner layer, consisted of lamellae alternating with interlamellae of lower electron density, in all three species; an inner layer of golden severum was $15\sim17$ layers, that of convic cichlid was $14\sim16$ layers, and that of discus was $18\sim19$ layers.

• Journal of Fisheries and Marine Sciences Education
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• v.15 no.2
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• pp.135-144
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• 2003

1. The appearance of fisheries animals and plants of investigation areas were fishes, 20 species; algae, 9 species; molluska, 6 species; arthropod, 12 species; echinoderm, 5 species by confirmed appearance species. 2. The C.P.U.E by trap(1pcs of trap) were 3.95 species and weight of 2,098g, mainly catching species are greenling and jacopever(94.16%). The C.P.U.E by long liner(long liner 1coil, 100pcs) were 11.7species and weight of 6,418g, It occupied jacopever(35.63%) greenling(20.78%), bastard halibut(20.31%). The C.P.U.E of appearance species gill net(ipcs of gill net) were 5.05species and weight of 3,050g, It occupied jacopever(39.63%) greenling(29.83%), bastard halibut(17.47%). 3. The results of comparative analysis and natural species and stocked species, in case of bastard halibut, jacopever species were occupied species(83.33~92%), weight(86.86~96%). The stocked species were occupied species of 8.00~16.67%, weight of 4.00~13.14%. Provided the stocked projets were enacted effectively in future. The density of dwelling of stocked species were increase. Also, it will be contribute to the increase of fishermens income.