• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1837-1860
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• 2020

We propose a general framework for studying resource allocation problem and the tradeoff between spectral efficiency (SE) and energy efficiency (EE) for downlink traffic in power domain-non-orthogonal multiple access (PD-NOMA) and device to device (D2D) based heterogeneous cloud radio access networks (H-CRANs) under imperfect channel state information (CSI). The aim is jointly optimize radio remote head (RRH) selection, spectrum allocation and power control, which is formulated as a multi-objective optimization (MOO) problem that can be solved with weighted Tchebycheff method. We propose a low-complexity algorithm to solve user association, spectrum allocation and power coordination separately. We first compute the CSI for RRHs. Then we study allocating the cell users (CUs) and D2D groups to different subchannels by constructing a bipartite graph and Hungrarian algorithm. To solve the power control and EE-SE tradeoff problems, we decompose the target function into two subproblems. Then, we utilize successive convex program approach to lower the computational complexity. Moreover, we use Lagrangian method and KKT conditions to find the global optimum with low complexity, and get a fast convergence by subgradient method. Numerical simulation results demonstrate that by using PD-NOMA technique and H-CRAN with D2D communications, the system gets good EE-SE tradeoff performance.

• Journal of Information Technology Services
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• v.6 no.2
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• pp.63-80
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• 2007

In this paper, the function factors contributing to ITA/EA functions in their organizations, are suggested. Also the reasons to the construction of IT governance system and their effects on the their organizations are discussed and the relationships are verified by empirical model. From the survey, the data of the 227 respondents were collected and regression analysis was performed for validating the research model. ITA/EA functions consist of the IT infrastructure systemization, ITA/EA business process support, IT investment efficiency factors. And the factors of IT resource and performance management, IT process management, IT service management are included to IT governance. The main analysis results described significantly are shows as follows. At first, IT resource and performance management factor is effected by the ITA/EA business process support factor and IT investment efficiency factor. In similarly, IT service management factor is also affected by the factors such as ITA/EA business process support, IT investment efficiency, and IT infrastructure systemization. In additional analysis, IT investment efficiency factor in official sectors, ITA/EA business process support factor in private sectors respectively are described as the significant factors on the IT governance.

• Environmental and Resource Economics Review
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• v.10 no.2
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• pp.135-159
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• 2001

This study analyses the energy consumption increase by using a physical production index (PPI) based decomposition method. The energy efficiency of the Korean industry deteriorated to a large extent in the 1992 to 1997 period. This outcome, however, does not contradict the result of a previous study that the physical energy intensities (measured by energy use per production unit) decreased in four Korean energy intensive industries such as steel, cement, petrochemical and pulp and paper in the same period. Although the physical energy intensities in four industries considered decreased significantly, the energy efficiency of the Korean industry deteriorated because the increase in the value-added production was smaller than that in the physical production except for the steel industry. This outcome suggests that the reduction in the physical energy intensity alone will not result in reducing the economic energy intensity, thereby reducing the increase in the energy consumption of the Korean industry. Therefore, it necessitates to restructure the Korean industry towards a higher value-added production and to strengthen energy efficiency improvement efforts in the Korean industry. As the overinvestment in the energy intensive industries caused a deep price fall of Korean products and a reduction of the value added of the Korean industry and with it an increase in the economic energy intensity, a decrease in this intensity will highly depend on reducing the overcapacity in the energy intensive industries which was partly responsible for the currency and economic crisis of 1997.

• Environmental and Resource Economics Review
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• v.17 no.2
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• pp.255-286
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• 2008

In this paper, it is tried to combine the decomposition method and econometric analysis for the extension of the decomposition method. Since two approaches approach the energy efficiency problem in the different perspectives, it is believed that it is hard to reconcile the results of two approaches. In the results of energy intensity effect analysis with the econometric method, it is found that the increase in the energy price results in the improvement of energy intensity effect. In enconometric analysis of energy efficiency, the coefficient of a time trend measured as a proxy of energy efficiency is significant and has a negative effect on the energy consumption. This finding implies the energy efficiency improves very slowly over time. In addition, the directions of energy efficiency improvement in the decomposition method are consistent with those in the econometric analysis in four industries. This finding indicates that two methods may be in complementary cooperation for the analysis of energy efficiency. Therefore, it is needed the efforts to seek the complementarity between two methods for the enhancement of academic and policy implications.

• KIEAE Journal
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• v.9 no.3
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• pp.21-27
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• 2009

The goal of this paper is to determine the suitability evaluation indices of a riverside reservoir space planning by classifying major indicators and calculating AHP(Analytical Hierarchy Process) based weights of them. The major indicators were set up based on literature review and questionnaire survey to experts. Four indicator categories were developed: location, environment, resource availability and economical efficiency. And they were divided into 12 sub-categories for calculating AHP-based weights. First, as for the major indicator categories, the calculation shows that the weighted index of environment is the most important at 0.458, followed by location at 0.128, economical efficiency at 0.170 and resource availability at 0.154. This suggests that environment is getting more public attention and the reservoir is regarded as a facility that is connected to a river. Those weight values were considered in calculating final weights for each of 12 sub-categories. Among them water quality and ecological environment take top ranks at 0.190 and 0.186, respectively. The lower ranks include access 0.112, resource availability of site 0.082, tourism resource 0.078, users 0.076, available land 0.052, area of site 0.031, shape of site and deterioration level 0.030 and percentage of private land 0.030 - which represents general considerations in other space planning. The difference of the top rank (water quality, 0.190) and the last one (percentage of private land, 0.027) is 0.163. The above result shows that users regard environmental aspect and resource availability more important than easiness of construction.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.146-167
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• 2001

Korea and China are two opposite countries located aside Yellow Sea and co-utilize the East China Sea. The two countries are close together from geological point of view, however, the competitive development of resources was more emphasized than the cooperative development of resources between the two countries because the special policy relationship. Additionally, after the communist government of China was founded in 1949, the political conception between the two countries was quite different. Therefore the establishment of appropriate international fisheries co-operation was impossible, and the international management problems of fisheries resources in Yellow Sea and East China Sea were let alone. UN convention on the Law of the Sea came to force in 1994, Korea and China adopted the exclusive economic zone system in 1996. On the other hand, Fisheries Law in Korea was enacted in 1953 in order to management of fisheries resources, and also China was enacted fisheries law in 1986. The two countries control the fisheries effort through fisheries license system, meanwhile through prohibition fishing area, prohibition fishing period, limitation of net size, and limitation of body length to conserve and manage the fisheries resource. The serious management methods of resource management in the two countries are similar such as the creation of promptly decreased species and those species that have commercial value, discharge of fish seedling stock, settlement of artificial reef and clean of fishing ground. Therefore, the two countries should consider not only the improvement of formal law system, but also how to recover the fisheries resources in circumference water zone and how to improve the efficiency of fisheries resource management. Specially the settlement and management of artificial reef should be chosen in the area that have the highest benefit to two countries, and should establish the common management system of discharge of fish seedling stock. And the two countries should adopt the same criteria through technical management and limitation of net size, limitation of body length, and prohibition area of special fisheries to ensure the highest fisheries benefit of fisherman in the two countries and the highest efficiency of fisheries resource management.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.575-584
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• 2019

Colletotrichum acutatum is a species complex responsible for anthracnose disease in a wide range of host plants. Strain C. acutatum KC05, which was previously isolated from an infected pepper in Gangwon Province of South Korea, was reidentified as C. scovillei using combined sequence analyses of multiple genes. As a prerequisite for understanding the pathogenic development of the pepper anthracnose pathogen, we optimized the transformation system of C. scovillei KC05. Protoplast generation from young hyphae of KC05 was optimal in an enzymatic digestion using a combined treatment of 2% lysing enzyme and 0.8% driselase in 1 M NH₄Cl for 3 h incubation. Prolonged incubation for more than 3 h decreased protoplast yields. Protoplast growth of KC05 was completely inhibited for 4 days on regeneration media containing 200 ㎍/ml hygromycin B, indicating the viability of this antibiotic as a selection marker. To evaluate transformation efficiency, we tested polyethylene glycol-mediated protoplast transformation of KC05 using 19 different loci found throughout 10 (of 27) scaffolds, covering approximately 84.1% of the entire genome. PCR screening showed that the average transformation efficiency was about 17.1% per 100 colonies. Southern blot analyses revealed that at least one transformant per locus had single copy integration of PCR-screened positive transformants. Our results provide valuable information for a functional genomics approach to the pepper anthracnose pathogen C. scovillei.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.5-10
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• 2015

D2D (Device-to-Device) communication underlaying LTE-advanced networks is a promising technology to improve the system capacity and spectral efficiency. By sharing the same radio resources with cellular user equipments, D2D communications can significantly enhance the overall spectral efficiency. However, it may cause interference between D2D link and cellular link. Careful resource allocation and interference coordination between cellular and D2D communications are very important and need to be properly handled. This paper proposes a radio resource allocation scheme based on FFFR (Flexible Fractional Frequency Reuse) for D2D communication underlaying cellular networks. The base station selects randomly resource blocks assigned to cellular users, and reuses them for a D2D pair. Through simulations, we have confirmed that the proposed scheme improves the system throughput, reduces the computational complexity, and mitigates the interference of D2D link and cellular link.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1532-1541
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• 2015

D2D(Device-to-Device) communication is a promising technology to improve the system capacity and spectral efficiency. By sharing the same radio resources with cellular user equipments, D2D communications can significantly enhance the overall spectral efficiency. However, it may cause interference between D2D link and cellular link. So, careful resource allocation and interference coordination between them are very important and need to be properly handled. This paper proposes a radio resource allocation scheme that decreases interference through the use of area grouping and D2D pair grouping. Simulations results are provided to verify the performance improvement of the proposed scheme in terms of the number of assigned resource blocks and computational complexity.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2995-3000
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• 2014

A sensitive concentration method utilising modified gas-purge microsyringe extraction (GP-MSE) was developed. Concentration (reduction in volume) to a microlitre volume was achieved. PAHs were utilised as semivolatile analytes to optimise the various parameters that affect the concentration efficiency. The injection rate and temperature were the key factors that affected the concentration efficiency. An efficient concentration (75.0-96.1%) of PAHs was obtained under the optimised conditions. The method exhibited good reproducibility (RSD values that ranged from 1.5 to 9.0%). The GP-MSE concentration method enhances the volume reduction (concentration factor), leading to a low method detection limit ($0.5-15ngL^{-1}$). Furthermore, this method offers the advantage of small-volume sampling, enabling even the detection of diurnal hourly changes in the concentration of PAHs in ambient air. Utilising this method in combination with GC-MS, the diurnal hourly flux of PAHs from the gas phase of ambient air was measured. Indeed, the proposed technique is a simple, fast, low-cost and environmentally friendly.