• Korean Journal of Remote Sensing
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• v.29 no.6
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• pp.663-670
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• 2013

Total Vertical Column Density (VCD) of $NO_2$, a key component in air quality and tropospheric chemistry was measured using a ground-based instrument, Pandora, in Seoul from March 2012 to October 2013. The $NO_2$ measurements using Pandora were compared with those obtained by satellite remote sensing from Ozone Monitoring Instrument (OMI) where the intercomparison characteristics were analyzed as a function of measurement geometry, cloud amount and aerosol loading. The negative biases of the OMI $NO_2$ VCD were larger when cloud amount and Aerosol Optical Depth (AOD) were higher. The correlation coefficient between $NO_2$ VCDs from Pandora and OMI was 0.53 for the entire measurement period, whereas the correlation coefficient between the two was 0.74 when the cloud amount and AOD were low (cloud amount<3, AOD<0.4). The low bias of OMI data was associated with the shielding effect of the cloud and the aerosols.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.84-88
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• 2001

Two methods of nitrogen application at the 4th leaf stage were evaluated in direct-seeding rice cultivation on dry paddy soil: one was the top dressing of nitrogen on dry paddy condition before irrigation (TNDP) for labor saving, and the other was the top dressing of nitrogen on dry paddy with mechanical rotavation of the inter-row space (TNDPIR) for increasing the efficiency of nitrogen. To evaluate these two application methods, leaf chlorophyll contents, growth characteristics and yields were compared with two conventional methods, basal application (BA) and top dressing on flooded paddy condition at the 4th leaf stage (TNFP). The SPAD value of rice in TNDP was similar with that in TNFP throughout the whole growth stage of rice. Also, there were no differences in rice growth and yield between the two methods. However, in TNDPIR, the SPAD value was the highest during tillering stage among the four application methods, and the tiller number, LAI at heading stage and the panicle number were higher than the two conventional methods.

• Journal of Fashion Business
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• v.21 no.1
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• pp.45-57
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• 2017

This study explored the current implementation status of corporate social responsibility (CSR) among textiles and apparel manufacturers and retailers in Korea, based on the Triple Bottom Line (TBL). We also investigated the provision of information related to CSR practices on the websites of companies. A quantitative content analysis was conducted to analyze the website disclosures of 61 listed companies categorized in the textiles, apparel, shoes, and luxury industry. Analysis was focused on the presence, accessibility, and the level of CSR website disclosure. Seven themes emerged by applying the constant comparison analysis. Using Scott's formula for pi, a high level of inter-coder reliability was achieved, ranging from 0.91 to 0.97. Regarding the three dimensions of CSR suggested in TBL, economic dimension was relatively more emphasized in the website disclosures of most companies, compared to social and environment dimensions. Website disclosures were further investigated, based on the product categories of each company. Limitations of this study and suggestions for future studies are discussed.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1519-1528
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• 2017

The paper proposes a well structured, component count waned single phase multilevel inverter (MLI) topology, which drives three different modules viz. Stipulation Based Sources Insertion (SBSI) module, Level Count Increasing (LCI) module and Inter-Linking H-Bridge (ILHB) module. The SBSI module confronts the number of basic sources needed in series/parallel to achieve required magnitude for any particular level. The LCI possesses an offsetting dc source and opuses to increase the number of levels and the ILHB module links the SBSI and LCI modules. A developed Hybrid Pulse Width Modulation (HPWM) strategy has PWM pulses for the switches of LCI module while the switches of the remaining two modules function at fundamental switching frequency. A fifteen level version of the proposed stipulation based sources insertion MLI (SBSIMLI) topology is simulated in MATLAB R2010a and a prototype of the similar specifications is constructed to validate the performance by experimental results. The comparison between the developed SBSIMLI topology and the competent topologies shows many interesting facts.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.128-134
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• 1988

This experiment was carried out to compare chemical composition of corn-cowpea inter cropping and corn monocropping plants at different harvestion time and obtained the following results. 1. In both cropping systems, the contents of crude fat and nitrogen free extract (NFE) were significantly increased (P<0.01), while that of crude protein crude fiber and crude ash were decreased (P<0.01) with each harvesting time. 2. The acid detergent fiber (ADF) and crude fiber contents were decreased same patterns in growing period, however, according to maturing of corn ears the difference between ADF and crude fiber contents reduced. 3. At mature stage, crude protein yields per 10a in corn monocropping and corn-cowpea intercropping system were 127.6kg and 152.1kg, respectively. The difference of crude protein content between corn-cowpea intercropping and corn monocropping system was 19.2%. 4. TDN yields of each cropping system, at mature stage, obtained similar results and TDN yields per 10a of corn monocropping and corn-cowpea intercropping system were 1006.1kg and 990.1, respectively. 5. Conseqently, corn-cowpea intercropping system could be increased protein yield without decreasing of dry matter yield in comparison with corn monocropping system.

• Journal of the Korean Operations Research and Management Science Society
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• v.16 no.2
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• pp.86-102
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• 1991

The purpose of this paper is to present a branch and bound algorithm for the hierarchical transportation network design problem in 2-level directed networks. This problem is to find the least cost of hierarchical transportation networks which consist of a primary path and a secondary path. The primary path is a simple path from a prespecified orgin node to a prespecified terminal node. All nodes must be either a transsipment node on the primary path or connected to that path via secondary arcs. This problem is formulated to a 0-1 inter programming problem with assignment and illegal subtour elimination equations as constaints. We show that the subproblem relaxing subtour elimination constraints is transformed to a linear programming problem by means of the totally unimodularity. Optimal solutions of this subproblem are polynoially obtained by the assignment algorithm and complementary slackness conditions. Therefore, the optimal value of this subproblme is used as a lower bound. When an optimal solution of the subproblem has an illegal subtour, a better disjoint rule is adopted as the branching strategy for reducing the number of branched problems. The computational comparison between the least bound rule and the depth first rule for the search strategy is given.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.121-138
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• 1999

This study was carried out to evaluate the performance of a sampling and analytical methodology for the measurement of selected volatile organic compounds (VOCs) in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/FID and GC/MSD analysis. Target analytes were aromatic VOCs, including BTEX, 1,3,5-and 1,2,4,-trimethylbenzenes(TMBs), and naphthalene. The methodology was investigatedwith a wide range of performance criteria such as repeatability, linearity, lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal and external standards. standards. Stability of samples collected on adsorbent tubes during storage was also investigated. In addition, the sampling and analytical method developed during this study was applied to real samples duplicately collected in various indoor and outdoor environments. Precisions for the duplicate samples and distributed volume samples appeared to be well comparable with the performance criteria recommended by USEPA TO-17. The audit accuracy was estimated by inter-lab comparison of both duplicate samples and standard materials between the two independent labs. The overall precision and accuracy of the method were estimated to be within 30% for major aromatic VOCs such as BTEX. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.125-131
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• 2017

In this paper, an efficient structure of device-to-device (D2D) synchronization preamble is proposed to meet the enhanced time and frequency synchronization requirements for D2D communication. D2D communication can be applied not only for the cellular communications, but also unmaned aerial vehicle communications and vehicle-to vehicle communication. The proposed preamble structure is transmitting signals at every odd subcarriers, and empty the other subcarriers to minimize the effect of inter-carrier interference. According to the simulation results, the proposed preamble structure provides improved time offset estimation performance, without degrading frequency offset estimation performance compared to the current LTE D2D preamble.

• Journal of Korean Library and Information Science Society
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• v.2
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• pp.1-21
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• 1975

Thc purposc of this .study is for ri~aking a model of building a library collcction dcnizn~cd on th.3 curriculum through thc inter-comparison of 15 standards for collcgc ant1 anivcrsily libraries in 5 countries (U. S. A.. Great Ikitain, Canada, Japan, and Icorca) Thc rcsult of thcscl colnpsrisons is as follow.. (1) Qu;~nlitalivc scope: of thc cull(:ction: (r/ Standards for a minimal collcction arc presented to about 100,000 vols (20-30 vols per student) for a ncw university and about 40,000 vols (40 vols pcr studcnt) for a nrnr collcge. $)$ Standards for a working collcction arc prescnted to 70-80 vols per student for a univer:aity and 50-60 vols per student for a college. $$ Standard for an intcnsive rescc~rch collcction is presented to morc than 100 vols p::r studcnt. (2) Stop: of the annual incrc;lsc cf thc collection: (i: Standard for a minimal collcction is ~~rescntcdto 1.4-2 vols per studcnt. $$ Standard for an intensive rrscarch or working collection is pcrsented to 4-5 vols pcr studcnt. (3) Scope of thc anni.1a1 budgetary standards: In Grcat I3ritain and U.S. A.. th-re aro assigned to 1 . 5 ~ 2 % of the collcge and university cxpcnditurr for books. $,$ In our country, it is prcscntcd to 3.5% of thc collcge and university expenditure for books, whcn my calculating by thc various factor analysis.

• Korean Journal of Materials Research
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• v.20 no.9
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• pp.478-482
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• 2010

A series of molecular dynamic (MD), finite element (FE) and ab initio simulations are carried out to establish suitable modeling schemes for the continuum-based analysis of aluminum matrix nanocomposites reinforced with carbon nanotubes (CNTs). From a comparison of the MD with FE models and inferences based on bond structures and electron distributions, we propose that the effective thickness of a CNT wall for its continuum representation should be related to the graphitic inter-planar spacing of 3.4${\AA}$. We also show that shell element representation of a CNT structure in the FE models properly simulated the carbon-carbon covalent bonding and long-range interactions in terms of the load-displacement behaviors. Estimation of the effective interfacial elastic properties by ab initio simulations showed that the in-plane interfacial bond strength is negligibly weaker than the normal counterpart due to the nature of the weak secondary bonding at the CNT-Al interface. Therefore, we suggest that a third-phase solid element representation of the CNT-Al interface in nanocomposites is not physically meaningful and that spring or bar element representation of the weak interfacial bonding would be more appropriate as in the cases of polymer matrix counterparts. The possibility of treating the interface as a simply contacted phase boundary is also discussed.