• Journal of the Korean Institute of Landscape Architecture
• /
• v.49 no.2
• /
• pp.27-40
• /
• 2021

This study was carried out for the description of the conflicts on the measurement of the root collar diameter of the landscape trees that are currently being produced, distributed, and planted in S. Korea, and for determination of the standard for root collar diameter measurement. The difference in consciousness of appropriate measurement of root collar diameter among different ages of landscape practitioners was statistically significant at p<0.05 level. It seemed to be due to the difference in the amount of field experiences among different age groups. On "the ambiguity of measuring the root collar diameter' of landscape trees", the consciousness was significantly different at p<0.05 level among job positions. On "Improvement of measurement criteria for landscape trees," it was significantly different at p<0.05 level among job types. This was thought to be due to the disagreement between the client and the contractor. On "prevention of topsoil removal" when excavating landscape trees, the consciousness was significantly different at p<0.001 level among different age groups, and different at p<0.01 level among different occupations, and different at p<0.05 level among different working area. The consciousness on "removing top soil when excavating landscape trees and rooting after transplantation" was not significantly different. The consciousness on the conflict caused by "ambiguity in root collar diameter measurement criteria" was high with an average of 3.85 for job type, occupation, jop position, and work experience. It was higher for landscape contractors than public institutions. The higher job positions and more experiences, the more conflicts. The consciousness on the appropriate position of root collar diameter measurement for landscape trees revealed that measuring at above-ground part (66.5%) was prefered to the underground part (33.0%). During the excavation of landscape trees for transplant, topsoil removal up to average depth of -2cm to -4cm was favored by 84.0%, and the purpose of removing topsoil was recognized as 'to increase the size and unit cost' by 59.7%.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.6
• /
• pp.369-381
• /
• 2017

It has been presumed that highly nonlinear skewed waves frequently observed in a surf zone could significantly influence the transmission behaviour via a porous wave breaker due to its larger inertia force than its nonlinear counterparts of zero skewness [Cnoidal waves]. In this study, in order to confirm this perception, a numerical simulation has been implemented for 6 waves the skewness of that range from 1.02 to 1.032. A numerical simulation are based on the Tool Box called as the ihFoam that has its roots on the OpenFoam. Skewed waves are guided by the shoal of 1:30 slope, and the flow in the porous media are analyzed by adding the additional damping term into the RANS (Reynolds Averaged Navier-Stokes equation). Numerical results show that the highly nonlinear skewed waves are of higher transmitted ratio than its counterparts due to its stronger inertia force. In this study, in order to see whether or not the damping at the porous structure has an effect on the wave celerity, we also derived the dispersive relationships of Nonlinear Shallow Water Eq. [NSW] with damping at the porous structure being accounted. The newly derived dispersive relationships shows that the phase lag between the damping friction and the free surface elevation due to waves significantly influence the wave celerity.

• Applied Chemistry for Engineering
• /
• v.9 no.3
• /
• pp.377-382
• /
• 1998

This study was carried out to investigate the relation between surface acidity and interfacial electrical characteristics of surface-treated ${\gamma}-alumina$ whose surface activity was increased. The points of zero charge (P. Z. C.) of ${\gamma}-alumina$ whose surface is treated with the sulfuric, nitric and hydro-chloric acid of various concentration were measured from the site-binding theory and mass transport method. The surface active sites were measured by amine titration method and Hammett indicator method. The interfacial properties at alumina/KCl(aq) interface were measured by potentiometric titration. From the experimental results, the following results were obtained. Pure ${\gamma}-alumina$ surface acidity decreases with the increase of calcination temperature at strength $H_o{\leq}+9.3$ Surface-treated alumina acidic properties increase with the anion loading on alumina surface. The surface ionization constants decrease with anion loading on alumina surface, then P. Z. C. decreases with acid amount on alumina surface. Acid amount of surface treated alumina can be correlated with surface charge density at strength $H_o{\leq}+4.8$ as follows. $SO_4^2-/Al_2O_3:Q_A=-0.172ln(0.0418{\sigma}+1.448)$ $NO_3^-/Al_2O_3:Q_A=-0.024{\sigma}-0.0189$ $Cl^-/Al_2O_3:Q_A=-0.01{\sigma}-0.2006$.

• Journal of the Korean association of regional geographers
• /
• v.14 no.3
• /
• pp.239-253
• /
• 2008

This paper aims to explore the viability of a rural-industrial complex neighbouring in the metropolitan area and suggest policy implications for the restructuring of the rural industrial complex. In particular, the paper focuses on the location and management practices of the firms operating in the industrial complex. Research shows that the key elements of the viability of the rural industrial complex in Koryung-Gun are the geographical and relational proximities to the metropolitan city of Daegu and the decentralization of urban industries towards rural areas neighbouring in the large city as a result of the deterioration of location conditions in the large city. It is revealed that the major pull factors of location are 'availability of cheap industrial sites', 'agglomeration in a specialized industry' and 'proximity to major customers and suppliers' rather than 'availability of labour pool'. However, it shows that 'weak university-industry linkages' and 'insufficiency of cooperation culture' are the major limitations to attracting firms. In the context of pub1ic policy, the author argues that the restructuring of the rural industrial complex should be sought to promote social infrastructures centered on networks and learning rather than firm centered financial and tax incentives.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.3
• /
• pp.757-767
• /
• 2018

In the propane dehydrogenation reaction proceeding at high temperature, the main cause of deactivation of the catalyst is coke deposition and sintering. In order to investigate the catalysts for reducing such inactivation, we have investigated the applicability of $MgAl_2O_4$ as a carrier for the catalytic dehydrogenation reaction. $MgAl_2O_4$ was prepared by Alcohthermal method at calcination temperature of 800, 900, $1000^{\circ}C$, and $Pt-Sn/MgAl_2O_4$ catalyst was prepared by supporting Pt and Sn by co-impregnation method. The reaction temperature was conducted at a high temperature of 650, $600^{\circ}C$ to confirm the thermal stability. As a result of the reaction experiment, it was confirmed that the conversion rate and yield of propane dehydrogenation reaction test were higher than that of the carrier-applied catalyst having a carrier calcination temperature of 900 and $1000^{\circ}C$, when the carrier-applied catalyst having a calcination temperature of $800^{\circ}C$ was used, It was found that the yield was higher than that of $Pt-Sn/{\theta}-Al_2O_3$ at $650^{\circ}C$. TGA, BET, XRD, CO-chemisorption, and SEM-EDS analyzes were performed for characterization. $MgAl_2O_4-800^{\circ}C$ was correlated with the relationship between good yield, Pt dispersion and low deactivation rate.

• Clean Technology
• /
• v.19 no.3
• /
• pp.333-341
• /
• 2013

This paper presents results on $CO_2$ gasification of 17 raw coals containing a wide range of volatile matter (21-57 wt%). The gasification is performed using a TGA under $CO_2$ and also under $N_2$ atmosphere. An amount of weight loss with increasing temperature is proportional to that of volatile matter in a coal under $N_2$ atmosphere. Reactivity of $CO_2$ gasification also increases with a content of volatile matter. However, the correlation is a little scattered. Oxygenated functional groups in a coal are generally reactive and therefore, an increase in O/C ratio leads to enhanced reactivity. However, $CO_2$ reactivity is affected by neither H/C ratio nor a content of ashes that possibly activate the gasification reaction. These findings are also applicable to steam coal gasification and the reactivity series are confirmed in the test at a fixed bed reactor.

• Journal of Korea Spatial Information System Society
• /
• v.1 no.1 s.1
• /
• pp.5-18
• /
• 1999

Recently, the necessity of automatic knowledge extraction from spatial data stored in spatial databases has been increased. Spatial data mining can be defined as the extraction of implicit knowledge, spatial relationships, or other knowledge not explicitly stored in spatial databases. In order to extract useful knowledge from spatial data, an object management system that can store spatial data efficiently, provide very fast indexing & searching mechanisms, and support a distributed computing environment is needed. In this paper, we designed and implemented an open object management system for spatial data mining, that supports efficient management of spatial, aspatial, and knowledge data. In order to develop this system, we used Open OODB that is a widely used object management system. However, the lark of facilities for spatial data mining in Open OODB, we extended it to support spatial data type, dynamic class generation, object-oriented inheritance, spatial index, spatial operations, etc. In addition, for further increasement of interoperability with other spatial database management systems or data mining systems, we adopted international standards such as ODMG 2.0 for data modeling, SDTS(Spatial Data Transfer Standard) for modeling and exchanging spatial data, and OpenGIS Simple Features Specification for CORBA for connecting clients and servers efficiently.

• The Journal of Engineering Geology
• /
• v.21 no.1
• /
• pp.15-24
• /
• 2011

To clarify the distribution of joints and fracture zones in the Cheongju granitic mass, we analyzed drill-core and geophysical well-logging data obtained at two boreholes located 30 m from each other. Lithological properties were investigated from the drill-core data and the samples were classified based on the rock mass rating (RMR) and on rock quality designation (RQD). Subsurface discontinuities within soft and hard rocks were examined by geophysical well-logging and cross-hole seismic tomography. The velocity structures constructed from seismic tomography are well correlated with the profile of bedrock depth, previously mapped from a seismic refraction survey. Dynamic elastic moduli, obtained from full waveform sonic and ${\gamma}-{\gamma}$ logging, were interrelated with P-wave velocities to investigate the dynamic properties of the rock mass. Compared with the correlation graph between elastic moduli and velocities for hard rock at borehole BH-1, the correlation points for BH-2 data showed a wide scatter. These scattered points reflect the greater abundance of joints and fractures near borehole BH-2. This interpretation is supported by observations by acoustic televiewer (ATV) and optical televiewer (OTV) image loggings.

• Science of Emotion and Sensibility
• /
• v.23 no.1
• /
• pp.3-16
• /
• 2020

Recently, as the fashion e-commerce market has expanded, the proportion of online shops that are growing rapidly has increased and with them so too has competition. Most retailers operating online shops need their own competitiveness, and accordingly, the need to develop their logistics service quality components is increasing. This study investigated the quality of the logistics services, which is a factor of the logistics service quality of the internet shop. It influences customer satisfaction and repurchase intention by collecting samples from the customers using online fashion shops. Two hundred customers who shop online were surveyed to extract the data. The sample was subjected to basic statistical analysis using the SPSS 25.0 package, and factor analysis, t-test, ANOVA, and correlation analysis were performed. The results of this study showed that the information quality of proactive return, promptness of the return process, and reliability of the return cost had a positive impact on customer satisfaction, and it had a significant influence on the customer's repurchase intention to the online store. A selection of shops showed high amounts of return reasons, high customer satisfaction, and high repurchase, whereas, in general, many others scored poorly across these criteria. This suggests that a retailer operating online should consider pages for receiving information plus sales content in addition to the quality and constituent factors of its logistics services for returns that influence repurchase and satisfaction.

• Journal of Radiation Protection and Research
• /
• v.15 no.1
• /
• pp.9-13
• /
• 1990

1959년 한국원자력연구소가 창립됨과 동시에 &Health Physics&, 즉 보건물리라고 하는 명칭과 조직이 탄생되어, 방사선안전관리의 실무와 보건물리의 연구가 시작되었다. 최초 10년간은 선진제국의 보건물리분야의 연구와 기술을 추적하여 우리나라의 방사선안전관리 기술의 기초를 다지는 시기로서 개인방사선모니터링기술, 환경방사선(능) 모니터링기술 및 방사선방어용계측기기의 교정기술 개발에 중점을 두고 연구개발이 추진되었으며, TRIGA Mark-II 연구용원자로의 가동에 따라 원자로 생체차폐체의 건전성 검증에 관한 유익한 방사선량 측정자료도 얻게 되었다. 즉 이 기간은 방사선안전관리의 체제정비 및 기초기술 확립에 노력한 기간이었다. 1970년대는 원자력 연구개발에 대한 기본방향과 정책의 변경등으로 보건물리 연구조직은 방사선안전관리, 환경연구 그리고 방사화학분야로 분산되었으며, 그로인하여 연구개발활동은 거의 정체되어 겨우 방사선안전관리 실무만이 그 명맥을 유지하였다. 그 결과 우리나라 방사선안전관리 및 그와 관련된 연구개발의 기반이 흔들리게 되었으나, 그러한 환경하에서도 방사선량측정평가기술, 방사선차폐설계기술 및 원자로사고시 피폭선량평가기술의 선진화에 필요한 지식을 얻었으며, 방사선 안전관리에 유익한 실무경험도 축적하게 되었다. 1980년대는 통합된 원자력 연구개발체제의 구축으로 방사선작업종사자 및 일반공중의 피폭저감화 기술개발에 필요한 각종 최신기술을 도입하였고, 관리업무에 있어서도 측정의 정확도와 신뢰성향상 및 새로운 관리기술의 개발에 많은 노력을 한 결과, 유익한성과를 얻게된 기간이다. 특히, 이 기간은 방사선안전관리기술의 선진화를 위한 지식이 축적되어 90년대의 방사선안전관리기술자립화를 위한 전환기로서, 이와같이 축적된 기술은 원자력의 평화적 이용에 크게 기여할 것으로 기대된다.서 dithiothreitol를 투여한 군에서는 우라늄단독투여군에 비해 cretinine의 배설이 상당히 증가하였다(P<0.05). 6. 우라늄오염에 의한 신장의 소견에 있어 우라늄단독투여군은 근위곡세뇨관상피의 공포화 및 종창, microvilli와 brush border의 손실, 세뇨관 상피의 괴사가 관찰되었으며, 간장의 충혈, 중심성 괴사 및 모세관 확장증도 관찰되었다. 그리고 sodium bicarbonate와 생리적 식염수를 병행투여한 군과 우라늄을 투여하고 30분이 지나서 dithiothreitol를 투여한 군에서는 우라늄 단독투여군에 비해 높은 방호효과가 관찰되었으나 다른 실험군에서는 큰 효과가 없는 것으로 나타났다. 결론적으로 우라늄의 체내오염시에는 sodium bicarbonate와 생리적 식염수를 가능한 빨리 병행투여하거나 dithiothreitol을 체내오염후 30분이 지나서 투여하는 방법이 우라늄오염에 대한 제염에 매우 유효할 것으로 생각되며, 특히 우라늄에 의한 인체장해를 유의하게 경감시켜줄 것으로 사료되었다.내의 어떤 부위와도 관계가 되는 것으로 간주되는데 이것이 $(^3H)$ QNB가 $(^3H)$ NMS보다 높은 최대 결합능력 $(B_{max})$을 나타낼 이유이다. (b) 두 종류의 다른 제제에서 우리는 같은 양상의 결과를 관찰하었기에 결점이 많은 homogenates 제제보다는 intact cell aggregates 제제를 수용체 연구에 대한 새로운 실험모형(experiment model)으로 사용할 수 있는 가능성을 제시하고자 한다.$가 38.8%로 가장 많고, 그 다음이 ${\ulcorner}$l9세(歲)이후${\lrcorner}$가 25.2%로서 전체