• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.127-140
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• 1988

The management of sewage and rainfall runoff becomes an emerging problem with the growth of urban communities. From the uncontrollable excess intensity or amount of rainfall, the conditions of sewer surcharge or manhole overflow could be generated in the combined sewer network where municipal or industrial wastewaters and rainfall runoff flow. The predictive model far the prevention of property and human life losses from this inundation was studied in this research. In the development of a mathematical flow model for the combined sewer surcharge and overflow, the Preissmann Slot concept and the four-point implicit method of finite difference were utilized. For the usage in personal computer, the overlapping segment method that required less memory storage was adopted. Through the simulation of hypothetical sewer network, the conservation of discharge volume was checked, and the usefulness of the Preissmann Slot was assured from the temporal distribution of discharge and depth along the sewer network. Also the possible field application for the correction of sewer diameters and slopes in the design of sewer network which has no surcharge/overflow condition was suggested.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.1
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• pp.24-34
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• 2001

The authors reconstruct a mooring type underwater positioning system to measure the movement of bag-net in a set-net by long base line mode with four transponders attached on the bag-net in latitudinal and a transponder fixed on the sea bed. To confirm the practical use of the system, the field experiments were carried out at the Jaran Bay, Kosung, Kyungnam Prov., on October 6, 2000 (neap tide) and November 28, 2000 (spring tide). And the vertical oscillation of bag-net was observed with three data loggers attached on the bottom of bag-net in longitudinal on November 28, 2000. The longitudinal movement range, the latitudinal one and the vertical one of the bag-net were 3.2 m, 3.4 m and 2.1 m. respectively. At the spring tide, these variations were 7.8 m, 7.8 m and 5.0 m, respectively. The vertical oscillation range about the bottom of the bag-net at near point of the slope net, at the middle part and at far point from the slope net were 3.2 m, 3.7 m and 8.4 m, respectively. The depth of the bottom net was decreased and its vertical oscillation appeared frequently when the current speed was more than 10 cm/s and the current direction was significantly different from the longitudinal axis of the bag-net. The variation of hydrophone coordinates measured by the transponder fixed on the sea bed presents that hydrophones equipped to the frame line of the set-net could be moved within several meters due to the tidal current. The fact indicates that the compensation of hydrophone coordinates is necessary to reduce the measuring errors. The position measuring errors of x, y and z axis of the system measured in the cage of aquaculture were 0.6 m, 0.8 m, and 1.2 m, respectively. And the errors of the transponders those were close to the base lines or placed in the baselines were smaller than those of others.

• Korean Security Journal
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• no.50
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• pp.145-172
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• 2017

In 2015 the Department of Education announced that it will make downsizing efforts by recommending classified downsizing ratio according to the evaluation of universities for active support toward autonomous efforts of universities with the possibilities of reform and qualitative structural reform for customized human resource cultivation according to the social demands. This is the preemtive structural reform preparing against the rapid decrease of the number of students, and the preparation for changing into competitive universities so that customized human resource that is needed in the society can be trained. Security Science Departments of Korea, first established in 1996, need changes in curriculum in order to prepare for the fourth revolution of the future, and are stagnant on the education goal and employment course. Therefore the adoption of related certificates, curriculum, NCS, and professional curriculum is needed. For example, Hansei University, Chung-Ang University, and Far East University have established the Department of Industrial Security, and Kyonggi University and Sungshin Women's University have established the Department of Convergence Security. Also, Konkuk University has established the Graduate School of Security and Disasters, the Graduate School of Information and Policy, the Graduate School of Criminal Justice, Gachon University the Graduate School of National Security, Sungkyunkwan University the Graduate School of Strategic Studies. This shows that the field of Security Science should not settle for itself. This article analyzes current curriculum and subjects of security, police, industrial security, military related academic departments of key universities. It is necessary to prepare for the future by predicting the change from the merge of academic departments and the demands of the times. As technical colleges are adopting NCS, this is the time to seek for systematic collaboration between universities and technical colleges and between industry, government, and academida.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.462-466
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• 2006

Close-to-nature stream evaluation is one of the processing to make the streams over in order to keep them natural. It is integral to evaluate and make an accurate analysis of them on the purpose of maintaining streams healthy. For many instances, there are, stream organization evaluation for restoration by German government, evaluation for ecosystem protection in natural preserves by New Zealand government, and stream-view evaluation for restoration by Britain government so on. In case of the country there are analysis and evaluation of stream physical organization by Cho, Yong-hyun, Close-to-nature stream evaluation for restoration by Kim, Dong-chan, evaluation of stream properties in korea by Park, Bong-jin. Close-to-nature evaluation by Lim, Chan-uk, that is advanced version of Park, Bong-jin's, shows form of stream including waterway curve, sand bar, diversity of flow, river bed material, diversity of minor bed, minor bed bank protection works, bank protection material. It also does environment of stream including side of minor bed vegetation, width of surface of the water/width of the river etc.. By the way, this evaluation does not have free access to apply those details above in the field, it often happens that you get various outcome from the one spot. so you must need more realistic testing method to obtain more accurate data. Remote sensing method is highly recommended because this is very useful for collecting realistic data of vegetation index. what is more, it can not only scan even the minimum area within its resolving power but also do obtain data anytime. Vegetation index indicates Ratio vegetation index, Normalized difference vegetation index, Soil adjusted vegetation index, Atmospherically resistant vegetation index etc.. The research is focusing on Cheokgwa stream which is the branch of Taehwa river and shows 19 sectioned Close-to-nature stream performed according to the method by Lim, chan-uk. Besides let you know vegetation index came from image data of satellite landsat 7 with the variation of buffering area, of the day 9. may. 2003. Of all, the outcome 0.758 at 200m buffer-zone of NDVI was the best we have got so far.

• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.265-280
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• 2003

The Mugeuk mineralized area that associated with the pull-apart type Cretaceous Eumseong basin is composed of several gold-silver vein deposits that are emplaced in late Cretaceous biotite granite. The gold-silver deposits in the area show various hydrothermal alteration zones as well as Au/Ag ratios and ore mineralogy. The Geumbong mine showing relatively high gold fineness is composed of multiple veins and show alteration pattern; vein \longrightarrow phyllic \longrightarrow subphyllic \longrightarrow propylitic \longrightarrow subpropylitic zone. In contrast, The Taegeuk mines show the low fineness values, in far southern part are characterized by increasing tendency of simple and/or stockwork veins. The deposit displays alteration pattern; vein \longrightarrow propylitic \longrightarrow subpropylitic zone. Variations of alteration zone with depth show that phyllic zone are dominant in deeper level and propylitic zone sporadically overlapped by argillic zone are dominant in shallow level. The differences of alteration pattern between the gold-silver deposits are reflect the evolution of the hydrothermal fluids; the ore-forming fluids of the Geumbong mine are at relatively high temperature and salinity and highly-evolved meteoric water, developing phyllic zone, the Taegeuk mine containing greater amounts of less-evolved meteoric waters shows relatively low temperature and salinity in ore-forming fluids, developing propylitic zone. The various physicochemical environment for gold-silver mineralization in the Mugeuk mineralized area is due to proximity from heat source area (Mugeuk mine) to marginal area (Taegeuk mine) in a geothermal field. Therefore, it is suggested that the criteria for project exploration in the area are to focus on the area proximal to heat source and phyllic zone.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.25-36
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• 2001

The purpose of this paper is to discuss the effects of soil properties such as liquid limit, water content, etc. on the compression index and to propose the empirical equation of compression index far regional clay and to verify the application Back Propagation Neural Network(BPNN). The compression index values obtained from laboratory tests are in the range of 0.01 to 3.06 for clay soils sampled in eleven regions. As the compare with the results of laboratory test and the predicted compression index value from the proposed empirical equations, the results of empirical equations including single soil parameter have a possibility to be overestimated. Also, the results of empirical equations including multiple soil parameters closed to the measured value more than that of empirical equations including single soil parameter, but the standard error for measured value obtained larger than 0.05. For these reasons, the empirical equations including single or multiple soil parameters proposed base on the results of laboratory test and the determination coefficient is up to 0.89. The result of BPNN shows that correlation coefficient and standard error between test and neural network result is larger than 0.925 and smaller than 0.0196, which means high correlativity, respectively. Especially, the estimated result by neural network, using only three parameters such as natural water content, dry unit weight and in-situ void ratio among various factors is available to the estimation of compression index and the correlation coefficient is 0.974. This result verified the possibility that if BPNN use, the compression index can be predicted by the parameters, which obtained from simplex field test.

• Proceedings of the KSEEG Conference
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• 2002.06a
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• pp.81-100
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• 2002

While most of regulatory communities in abroad recognize ' 'natural attenuation " to include degradation, dispersion, dilution, sorption (including precipitation and transformation), and volatilization as governing Processes, regulators prefer "degradation" because this mechanism destroys the contaminant of concern. Unfortunately, true degradation only applies to organic contaminants and short- lived radionuclides, and leaves most metals and long-lived radionuclides. The natural attenuation Processes may reduce the potential risk Posed by site contaminants in three ways: (i)contaminants could be converted to a less toxic form througy destructive processes such as biodegradation or abiotic transformations; (ii) potential exposure levels may be reduced by lowering concentrations (dilution and dispersion); and (iii) contaminant mobility and bioavailability may be reduced by sorption to geomedia. In this review, authors will focus will focul on "sorption" among the natural attenuation processes of hazardous inorganic contaminants including radionuclides. Note though that sorption and transformation processes of inorganic contaminants in the natural setting could be influenced by biotic activities but our discussion would limit only to geochemical reactions involved in the natural attenuation. All of the geochemical reactions have been studied in-depth by numerous researchers for many years to understand "retardation" process of contaminants in the geomedia. The most common approach for estimating retardation is the determination of distrubution coefficiendts ($K_{d}$) of contaminants using parametric or mechanistic models. As typocally used in fate and contaminant transport calculations such as predictive models of the natural attenuation, the $K_{d}$ is defined as the ratio of the contaminant concentration in the surrounding aqueous solution when the system is at equilibrium. Unfortunately, generic or default $K_{d}$ values can result in significant error when used to predict contaminant migration rate and to select a site remediation alternative. Thus, to input the best $K_{d}$ value in the contaminant transport model, it is essential that important geochemical processes affecting the transport should be identified and understood. Precipitation/dissolution and adsorption/desorption are considered the most important geochemical processes affecting the interaction of inorganic and radionuclide contaminants with geomedia at the near and far field, respectively. Most of contaminants to be discussed in this presentation are relatively immobile, i.e., have very high $K_{d}$ values under natural geochemical environments. Unfortunately, the obvious containment in a source area may not be good enough to qualify as monitored natural attenuation site unless owner demonstrate the efficacy if institutional controls that were put in place to protect potential receptors. In this view, natural attenuation as a remedial alternative for some of sites contaminated by hazardous-inorganic components is regulatory and public acceptance issues rather than scientific issue.

• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.165-173
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• 1995

This study was conducted to clarify not only the phytogeographical distribution but also species characteristics of Korean-native Anacardiaceae. 6 species of I genus were ascertained from herbarium specimens and field survey of natural population. Rhus verniciflua have been mainly cultivated in Wonju region, Kangwon-do and Hamyang region, Kyeongsangnam-do, could be cultivated in all parts of Korea, especially more in cold area. R. trichocarpa was distributed in all parts except for some far-islands of South in Korea. Petiole was especially reddish. Fruits are matured in June-July, and have stiff trichomes. R. sylvestris was widely distributed in the subtropical-temperate and temperate zone, and mainly distributed in the seashore and islands under 36$^{\circ}$ in Korea. Leaflets and petiole was reddish, and fruits were glabrous. R succedanea was only distributed in Jeju-do and several islands which is subtropical zone in Korea. Leaflets were lanceolate to oblong, characterized by little trichomes. R.chinensis is a ubiquitous tree which is widely distributed in the temperate zone, in Korea, and ranged perpendicularly to 800-900m. Inflorescense was characterized by apical site. Fruit was covered with dense short hairs and sometimes milky latex. R. ambigua was only distributed in subtropical zone, native in Kwang-do and Sangbaek-do, Yeochon-gun, Chunlanam-do in Korea. Especially, this species was a vine, trifoliolate and most poisonous. Leaflets were coriaceous, glabrous, and revolute type.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.36-41
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• 2018

This paper presents an implementation of a millimeter-wave(W band) multiflare-angle horn antenna. The proposed antenna is a multimode dual-polarized square horn having equal E- and H-plane beamwidths and consists of a multimode generating section, a four-square-waveguide exciter, orthomode transducers, and power combiners for the sum pattern formation. The antenna structure has been designed to allow for easy fabrication and the designed antenna has been fabricated to a precision of ${\pm}0.02mm$ by layer-by-layer machining and diffusion bonding. The input reflection coefficient and the radiation pattern of the fabricated antenna have been measured using a network analyzer and a far-field test facility. Measurements show that the proposed antenna has 17.7~18.3 dBi gain, $25.2{\sim}28.5^{\circ}$ beamwidth, and an input VSWR between 1.02~1.75, within ${\pm}0.5GHz$ from the center frequency.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.17-38
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• 2018

The purpose of present study was to examine whether the perceived distance is compressed to different extent according to the length of the tool in the object that is not reachable even when using the tool, and whether the perceived distance is compressed according to the tool length only in the object being pointed. In Experiment 1, we found by measuring the egocentric distance that the length of the tool causes the distance to the target to be closer to that of the object placed at a far distance. In Experiment 2, we found by measuring the egocentric distance that when the operated object and the non-operated object coexisted in the visual field, the length of the tool does not affect the distance perception to the non-pointed object. In Experiment 3, we found that the tool length affects only the distance perception of the operated object by measuring the exocentric distance which is the distance between the operated object and the target in the same environment as Experiment 2. The results of present experiment suggest that the compression of the perceived distance occurs at a distance that can not be reached by using the tool, and that the compression of the perceived distance is limited to the pointed object.