• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.780-785
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• 2012

Existing states of attached algae in the sedimentation basin was observed during late april to early october, and the attached algae were visible 7 days after of cleaning the trough and the communities of algae became larger with increasing the operation periods. Attached algae community included bluegreen algae (Oscillatoria sp.), diatom (Synedra sp.,) and green algae (Mougeotia sp., Oedogonium sp.) and suspended diatom (Stephanodiscus sp.) as well. Diatom (Cymbella sp., Navicula sp., Synedra sp. and Stephanodiscus sp.), green algae(Mougeotia sp. and Cosmarium sp.) and blue-green algae (Anabaena sp.) were detected in the effluent of sedimentation basin. The chlorophyll-a (chl-a)concentrations of algae community on a square centimeter after 14 and 28 days were distinctively different depended on the copper sulphate treatment. The concentration of chl-a were $4{\mu}g/L/cm^2$ and $19{\mu}g/L/cm^2$ for the copper sulphate treated water and $59{\mu}g/L/cm^2$ and $147{\mu}g/L/cm^2$ for the untreated water. Diatom algae fragments were observed in red-brownish sediments on the bottom of industrial water distribution basin and degraded blue-green and green algae formated organic sediments combined with oxidized iron.

• Journal of Nutrition and Health
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• v.38 no.9
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• pp.765-776
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• 2005

The purposes of this study were to a) examine IC (intellectual capital) circumstance of CFMC (contract foodservice management company), b) identify the correlation between IC of CFMC, c) analyze the cause and effect of IC in the viewpoint of contractor, client, and customer. The questionnaires of IC measurement were handed out to 108 CfHCs, there composing of main office employees, foodservice managers, customers, and clients of 207 school, 38 hospital, and 86 business/industry foodservices. The statistical data analysis was completed using SPSS Win (ver 12.0) for descriptive analysis, correlation analysis, simple linear regression analysis. First, CFMCs had operational experience for an average of 8 years and 8 months, and served an average of 38,540 meals a day. Most of the respondent companies operated 'food supply/distribution($50\%$)', 'catering ($46.7\%$)', and restaurant business ($43.3\%$)' except for institutional foodservice and managed an average of 66 clients for the contract period of 2 years and 3 months. Second, there was positive correlation between $\ulcorner$sales of foodservice$\lrcorner$ and 'market ability', $\ulcorner$client satisfaction$\lrcorner$ and necessary intellectual capital for managing branch/chain foodservice office, and $\ulcorner$customer satisfaction$\lrcorner$ and $\ulcorner$renewal and development$\lrcorner$, 'market ability', 'infrastructure support for foodservice operation', 'employee satisfaction', respectively. Finally, the result of the cause and effect analysis on CFMCs, clients, and customers was positively influenced by 'client satisfaction' with 'customer satisfaction', 'infrastructure support for foodservice operation' and 'customer satisfaction' with 'employee satisfaction', and 'infrastructure support for foodservice operation'. In conclusion, if CFMCs were to perform a routine checkups by utilizing CFMC's IC measuring tool, improvements in CFMC operational capacities as well as foodservice quality can be noted. Additionally, CFMCS can satisfy their client-customer relationship by employing internal marketing thechniques for employee, a more efficient infrastructure support system, and construc tive infrastructure utilization. Therefore, CFMCs can show significant improvement in their sales and foodservice quali-ty though continuous maintenance of the client and customer satisfaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.673-680
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• 2017

sump pump is a system that draws in water that is stored in a dam or reservoir. They are used to pump large amounts of water for cooling systems in large power plants, such as thermal and nuclear plants. However, if the flow and sump pump ratio are small, the flow rate increases around the inlet port. This causes a turbulent vortex or swirl flows. The turbulent flow reduces the performance and can cause failure. Various methods have been devised to solve the problem, but a correct solution has not been found for low water level. The most efficient solution is to install an anti-vortex device (AVD) or increase the length of the sump inlet, which makes the flow uniform. This paper presents a computational fluid dynamics (CFD) analysis of the flow characteristics in a sump pump for different sump inlet lengths and AVD types. Modeling was performed in three stages based on the pump intake, sump, and pump. For accurate analysis, the grid was made denser in the intake part, and the grid for the sump pump and AVD were also dense. 1.2-1.5 million grid elements were generated using ANSYS ICEM-CFD 14.5 with a mixture of tetra and prism elements. The analysis was done using the SST turbulence model of ANSYS CFX14.5, a commercial CFD program. The conditions were as follows: H.W.L 6.0 m, L.W.L 3.5, Qmax 4.000 kg/s, Qavg 3.500 kg/s Qmin 2.500 kg/s. The results of analysis by the vertex angle and velocity distribution are as follows. A sump pump with an Ext E-type AVD was accepted at a high water level. However, further studies are needed for a low water level using the Ext E-type AVD as a base.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.226-231
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• 2016

Binomial trees are used to price barrier options. Since barrier options are path dependent, option values of each node are calculated from binomial trees using backward induction. We use generalized Catalan numbers to determine the number of cases not reaching a barrier. We will generalize Catalan numbers by imposing upper and lower bounds. Reaching a barrier in binomial trees is determined by the difference between the number of up states and down states. If we count the cases that the differences between the up states and down states remain in a specific range, the probability of not reaching a barrier is obtained at a final node of the tree. With probabilities and option values at the final nodes of the tree, option prices are computable by discounting the expected option value at expiry. Without calculating option values in the middle nodes of binomial trees, option prices are computable only with final option values. We can obtain a probability distribution of exercising an option at expiry. Generalized Catalan numbers are expected to be applicable in many other areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.648-654
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• 2016

This paper investigates differences of tourism destination choices for sightseeing in Seoul between first-time visitors and repeat visitors. We constructed social network using secondary data from '2015 International Visitor Survey' and analyzed its density and centrality. Study results find that: (1) first-time and repeat visitors' tourism destinations are concentrated in areas located north of the Han river. The proximity of destinations suggests the positive effects resulting from the movement network. (2) As the result of degree centrality, closeness centrality, betweenness centrality, the highest ranking tourism destinations for both visitor groups are identical, but indexes of centralities in repeat visitors' destinations increase, including Shinchon/ Hongik University, Gangnam station, and Garosu-gil. Therefore, the roles of these destinations are becoming established as tourism hubs and are popular among younger visitors as well as attract repeat visitors. Results of this study will be a useful reference in developing and managing new tourism products.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.9-16
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• 2016

Wireless sensor networks (WSN) are composed of sensor nodes and a base station. The sensor nodes deploy a non-accessible area, receive critical information, and transmit it to the base station. The information received is applied to real-time monitoring, distribution, medical service, etc.. Recently, the WSN was extended to mobile wireless sensor networks (MWSN). The MWSN has been applied to wild animal tracking, marine ecology, etc.. The important issues are mobility and energy consumption in MWSN. Because of the limited energy of the sensor nodes, the energy consumption for data transmission affects the lifetime of the network. Therefore, efficient data transmission from the sensor nodes to the base station is necessary for sensing data. This paper, proposes an energy consumption model using two-tier clustering in mobile sensor networks (TTCM). This method divides the entire network into two layers. The mobility problem was considered, whole energy consumption was decreased and clustering methods of recent researches were analyzed for the proposed energy consumption model. Through analysis and simulation, the proposed TTCM was found to be better than the previous clustering method in mobile sensor networks at point of the network energy efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.366-374
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• 2017

In this study, we present a new product strategy corresponding to the needs of the consumer segment in the mobile convergence industry, which is a field with a very high interest, and the implications are as follows. First, we believe that mobile convergence will lead the market for products that are regarded by consumers as innovative. Second, it can be seen that it is more attractive to consumers to dramatically improve existing functions than to add multiple functions that are not so important. Third, the type of convergence preferred by each type of consumer differs. For consumers who are less innovative, less professional and more technologically fatigued, it was shown that breakthrough improvements in existing technologies lead to better evaluations than adding multiple innovations. In addition, highly innovative consumers are more likely to appreciate the addition of a variety of mediocre features, such as less convergent innovations than the existing ones, as well as mobile convergence. Moreover, there was no significant difference in the product attitudes between the consumers with low technological fatigue and the highly innovate ones.

• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.213-220
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• 2015

To elucidate the origin and patterns of establishment of insular plants on Ulleungdo Island, maternally inherited chloroplast DNA, which is useful for tracing seed movements, was used. Fagus multinervis, an endemic species that dominated broadleaf deciduous forests on Ulleungdo Island, is an excellent model for such a study. To understand the diversity and spatial distribution of the chloroplast haplotypes of F. multinervis, nucleotide sequences of the psbA-trnH region were determined from 144 individuals sampled throughout the island. Results of a phylogenetic analysis of the region with close relatives of F. multinervis suggest that F. multinervis is sister to a clade of F. japonica and F. engleriana. No haplotype variation was found within F. multinervis. This remarkably low cpDNA haplotype diversity is in contrast to the findings of previous allozyme studies of F. multinervis populations that showed high genetic diversity on Ulleungdo Island. Repeated colonization during the early stage of establishment via birds that migrated from a source area where the F. multinervis cpDNA haplotype was geographically structured may have resulted in the observed pattern of haplotype diversity. Alternatively, long-distance dispersal of seeds of the progenitor of F. multinervis via birds or typhoons to Ulleungdo may have been a single event, whereas the immigration of pollen from the mainland likely occurred frequently. Comparative phylogeographic studies of other species endemic to Ulleungdo Island and their close relatives on the neighboring mainland are necessary for a more complete understanding of the evolution of the island's native species.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.391-401
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• 2017

This study develops an indicator to manage regional variations of approval rates for long-term care (LTC) service. We used LTC insurance data for grade assessment that include 433,155 applicants from 227 LTC centers across Korea in 2015. The approval rate for each center was defined as the proportion of the numbers of approved applicants out of all applicants. We assumed that the approval rates depended on the characteristics of applicants. We estimated the 'standard' approval rates from a multiple linear regression analysis using the characteristics of applicants as independent variables. The difference between the observed and the standard rates was then defined as an indicator for deviation. A center having a large difference could be considered as a center with a potential error in grade assessment. We also examined if the characteristics of investigators affected the approval rates. We found that the socio-demographic characteristics of applicants and reapplication rate for LTC grade were independent factors affecting the approval rates. Centers having the management indicator values falling outside the middle 95% of the distribution were identified as centers with an error in grading. We expect that this study will contribute to enhancing reliability and equity in LTC grading.

• Polymer(Korea)
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• v.34 no.1
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• pp.20-24
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• 2010

In this study, ETFE-g-PSSA membranes with various degrees of grafting (DOG) and thicknesses were prepared by a simultaneous irradiation method. SEM-EDX instrument was applied to measure the relative distribution of sulfur which is corresponding to that of a grafted polymer over the Cross-section of the ETFE-g-PSSA membranes prepared at various irradiation conditions. The results indicate that to obtain the evenly-grafted membranes, a styrene/dichloromethane ratio is needed to be under 60 (v/v%), and a higher DOG is required as the film thickness increases. The effects of DOG and thickness on the ion exchanging capacity (IEC) and water uptake (WU) were investigated by measuring the IEC and WU values of the membranes with various DOG and thicknesses.