• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.26-33
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• 2005

The study was carried out to provide information about growth and ecological characteristics by site types of natural deciduous forest in Pyeongchang, Gangwon Province. The data were collected from four aspects(the East, the West, the South, and the North) with three elevation(higher than 1.000 m, 700~1,000 m, lower than 700 m) and three topographical conditions(ridge, hill, and valley). Growth parameters by site types were evaluated based on the growth performances of dbh for the last 5 to 10 years; which were also estimated based on both Pressler and Schneider formulae. In addition, ecological characteristics such as Shannon-Wiener's diversity index, evenness index and richness index were analyzed by site types. The management methods by site types were suggested by considering stand density, growth patterns, and ecological characteristics. It was found that the stands on the South and the East are necessary the tending practices to improve growth and ecological characteristics. On the other hand, the West and the North needed the tending practices focusing on stand density management to increase growth rate rather than ecological management. It was also found that the area lower than 700 m in elevation showed Higher growth rate than other areas. As a management standard considered in terms of growth rate, it was suggested that tending practices should be applied to the stands of which growth rate for the last 5 to 10 years were lower than 2%. Considering topographical conditions, valley area showed better ecological characteristics than both ridge and hilly areas. Consequently, it was revealed that the valley areas were suitable for the ecological management.

• Environmental and Resource Economics Review
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• v.19 no.1
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• pp.101-127
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• 2010

The purpose of the research is to tackle proximity effects (PEs) when nonmarket valuation method CVM is applied to environmental goods such as tidal flats. 1,000 households are surveyed in the ratio of national household for the research. The sample are reclassified into five areas by 30-minute distance. Log-linear are used to analysis PEs in the research. On conclusion log-linear model regarding income effects proves that PEs are apparently represented in NMVMs(${\theta}_1$ >0. ${\theta}_2$ >0 and $dum1{\neq}0$, $dum2{\neq}0$, $dum3{\neq}0$, $dum4{\neq}0$) as a result of a 5 per cent significant level of t -test and F-test, finally rejecting the null hypothesis. In addition, WTP of area I respondents shows 26 per cent more then that of area V respondents, which is from \87,969 to \64,866 in the open-ended format. Finally, the research proves that the PEs in CVM are evidently represented with the econometric model, hence the PEs have to be embedded into the questionnaire of non-market valuation methods with the environmental goods to reduce the underestimation and improve the estimation accuracy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.137-145
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• 2012

According to the National Police Agency, the total number of traffic accidents which occurred in 2010 was 226,878. Intersection accidents accounts for 44.8%, the largest portion of the entire traffic accidents. An research on the signalized intersection is constantly made, while an research on the unsignalized intersection is yet insufficient. This study selected traffic volume, road width, and sight distance as the input variables which affect unsignalized intersection accidents, and number of accidents as the output variable to build a model using ANFIS(Adaptive Neuro-Fuzzy Inference System). The forecast performance of this model is evaluated by comparing the actual measurement value with the forecasted value. The compatibility is evaluated by R2, the coefficient of determination, along with Mean Absolute Error (MAE) and Mean Square Error (MSE), the indicators which represent the degree of error and distribution. The result shows that the $R^2$ is 0.9817, while MAE and MSE are 0.4773 and 0.3037 respectively, which means that the explanatory power of the model is quite decent. This study is expected to provide the basic data for establishment of safety measure for unsignalized intersection and the improvement of traffic accidents.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.640-649
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• 2015

This study aims to investigate mediating effect of teenagers' spirituality on the relationship between Irrational Beliefs and self-esteem. For research, questionnaires were distributed to 500 teenagers aged 14 to 19. And data were collected from 419 persons. The average age of subjects was 15.8. The collected data verify by structural equation model. As a result, it was shown that the first research model was not good. Hence, according to the results of modifying the model after referring to model modification index, the first modified model showed ${\chi}2=222.527$, df=83,p<.000, CFI=.975, TLI=.968, NFI=.961 and RMSEA=.061. Therefore, it was shown that the model was suitable. According to the results of analyzing the effect of model at this point, it was shown that the direct effect which unreasonable beliefs had on self-esteem was .02, and indirect effect through the mediation of spirituality was .30. Hence, it was verified that spirituality mediated the effect which unreasonable beliefs had on self-esteem. When this is considered, it is thought that, if the level of spirituality is improved, the negative effect which teenagers' unreasonable beliefs had on self-esteem will decrease, though the unreasonable beliefs have a negative effect on self-esteem.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.207-215
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• 2017

With rapid development of IT technology and biotechnology, human lifespan is extended rapidly, and we are living in the era where aging becomes the social issue. Due to this aging problem, manpower is mainly replaced by Automated Guided Vehicles (AGV) in manufacturing factories or warehouse logistics transportation. Rate of AGV use increases sharply every year. AGVs, which were used only in Smart Factories, extends its usage into indoor and outdoor operation by changing their usages to container transportation that can carry huge containers in the harbor. With the expansion of AGVs usage, the importance of RCS (Remote Control System) is also increased. In this study, we surveyed and analyzed the characteristics and technology trends of technical features of AGV's RCS that are developing in various ways to establish quality evaluation system of AGV RCS. Based on this, and by referring to international quality assessment standards, ISO/IEC 25000 series, we derived evaluation items on functional suitability and usability to secure reliability of AGV RCS. Also, it is our intention to develop evaluation model using those derived usability and reliability evaluation items.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.23-34
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• 2018

Recently, mainly in downtown, there have been frequent safety incidents in underground space like ground subsidence and land sinking. Out of diverse coping measures, the government is carrying forward the establishment of underground space integrated map. As a core element of the underground space integrated map, the 3D geotechnical information is used as major data of underground space impact assessment obliged in accordance with the "Special Act on the Safety Control of Underground Space Safety". The construction method of 3D geotechnical information is drawn when establishing the basic establishment plan of underground space integrated map, and the continuous construction is performed by the Integrated DB Center of National Geotechnical Information. However, it is necessary to draw concrete measures with accuracy, efficiency, and utilization. This study drew the construction plan considering the accuracy, utilization, and efficiency of 3D geotechnical information for the support of underground space safety. For this, accuracy between elevation and underground level is compared using MVS and MakeJiban which are software to construct boring information with geotechnical information in geotechnical information portal system. In the results of general analysis, the milepost-based construction of whole strata in a lump would be the most suitable in the aspect of accuracy, utilization, and efficiency. Based on the results of this study, Plan to construct 3D geotechnical information will be pursued.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.674-681
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• 2015

This research conducts both experimental evaluation and resident's assessment of zero food waste system (ZFWS) in multifamily housing estates in order to explore the feasibility of ZFWS embedded in fermentation and extinction technology utilizing wood chips turned into fertilizer. Having been established in a multifamily housing estate, ZEFWS was proved to be functional and effective. During the 3-month experimental period, the weight between infused food waste and its reactor was reduced significantly enough, and the chemical analysis showed that the concentration of organic compounds went from 87.9% to 75.8%, $H_2O$ decreased from 69.7% to 45.5%, NaCl rose from 0.2% to 0.5%, pH increased from 4.6 to 7.8, and ATP escalated from 505.3 nmol/L to 723.5 nmol/L. Also, the chemical analysis of the output in the experimentation indicated adequacy of the organic fertilizer. In the self-administered questionnaire survey for residents participating in the field project, almost all the respondents viewed that ZFWS can compete with conventional food waste disposal methods and an idealistic way to upcycling food waste into fertilizer.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.3
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• pp.331-338
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• 2008

Coal-tar enamel, blown asphalt and polyethylene have been used as wrapping materials of steel pipe in Korea. Currently, every manufacturer produces wrapped steel pipes with different materials and methods, and little research has been performed to get on wrapping methods and materials. In this research, properties of wrapping material of steel pipe used for water supply have been evaluated. All of the materials tested in this work were found to meet the standard. Among the wrapping materials of steel pipe tested, blown asphalt and coal-tar enamel were reasonable in price, and their mechanical properties were excellent. The quality of the wrapped steel pipes was being melted easily in organic solvent. When coated thick, the load of the steel pipes was higher than necessary. Tensile strength of cathode exfoliation and PE 3-layer wrapping method was excellent. The pulling intensity of T-Die PE 3-layer was stronger than PE fluidized in PE wrapping method. Cathode exfoliation area was smaller than PE fluidized. Mechanical property and thermo-property of T-Die PE 3-layer were excellent and its anti-chemical property was great. Liquid epoxy can change the property of coating materials depending on the hardening condition and resin selection. Polyurethane used in this test showed a less adhesive strength with steel pipes than epoxy. Moisture absorbance rate was higher than Epoxy's, however. To utilize polyurethane as wrapping materials, basic property of the matter should be improved followed by finding the best suited coating condition. The method of PE 3-layer by extrude method appeared to be the best in this study. However, identification of other wrapping materials requires further additional tests.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.666-674
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• 2013

Physical disturbance, which induces a lack of flow rate, frequently occurs in freshwater ecosystem. Due to this, it is required to provide a new fish shelter to resolve. We installed a pilot scale test-bed to scrutinize the relationship between water level and the influence of fish shelter. The proposed ADP (artificial deep pool) is a fish shelter which composed of concrete materials. From the monitoring results in test-bed, it was observed that the population of fish was the highest at the 0.5 m in depth from the water level of experimental pond. But it was more appropriate for shallow water level (<0.3 m) to conserve the total number of fish by increasing the number per unit area despite of lower inner temperature and DO than outer environment. Therefore, inner of ADP was more efficient lentic system for fish to live due to higher WCS, OS, SS, and TS. In addition, there was a relative abundance of WCS fish species such as Acheilognathus koreensis (A. koreensis), Carassius carassius (C. carassius). Considered these results, it is suggested that ADP is appropriate to use for fish shelter and habitat for the fishes in lentic ecosystem.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.273-282
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• 2009

To render more valuable information, a spatial database is being constructed from digitalized maps in the geographic areas. Transferring file-based maps into a spatial database, facilitates the integration of larger databases and information retrieval using database functions. Geological mapping is the graphical interpretation results of the geological phenomenon by geological surveyors, which is different from other thematic maps produced quantitatively. These features make it difficult to construct geologic databases needing geologic interpretation about various meanings. For those reasons, several organizations in the USA and Australia are suggesting the data model for the database construction. But, it is hard to adapt to a domestic environment because of the representation differences of geological phenomenon. This paper suggests the data model adaptive in domestic environment analyzing 1:50,000 scales of geologic maps and more detailed mine geologic maps. The suggested model is a logical data model for the ArcGIS GeoDatabase. Using the model it can be efficiently applicable in the 1:50,000 scales of geological maps. It is expected that the geologic data model suggested in this paper can be used for integrated use and efficient management of geologic maps.