• Journal of the Economic Geographical Society of Korea
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• v.6 no.2
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• pp.327-338
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• 2003

The concept of industrial cluster began with the agglomeration economies occurring in a small scale place, which are mainly drawn from intense networking between companies, universities, research centers and other institutional bodies. Recently, however, as cooperation between autonomous administrative units and between industrial clusters has been more active than ever, there has emerged the concept of extended industrial cluster (EIC) and, subsequently, policy measures for nurturing it. This study focuses on the concept of EIC, mainly in the perspective of the need to adopt it into the industrial cluster literature. The study identifies the raison d'etre of EIC in the respects of the flexibility of geographic range, complementarity and cooperation between functions and regions, scale economies and productivity, and the development stage of industrial clusters. It also suggests how to establish the concept of EIC in the Korean context and how to apply EIC policy in the Korean industrial policy.

• ETRI Journal
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• v.31 no.2
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• pp.173-181
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• 2009

The growth of the World Wide Web and web-based applications is creating demand for high performance web servers to offer better throughput and shorter user-perceived latency. This demand leads to widely used cluster-based web servers in the Internet infrastructure. Load balancing algorithms play an important role in boosting the performance of cluster web servers. Previous load balancing algorithms suffer a significant performance drop under dynamic and database-driven workloads. We propose an estimation-based load balancing algorithm with admission control for cluster-based web servers. Because it is difficult to accurately determine the load of web servers, we propose an approximate policy. The algorithm classifies requests based on their service times and tracks the number of outstanding requests from each class in each web server node to dynamically estimate each web server load state. The available capacity of each web server is then computed and used for the load balancing and admission control decisions. The implementation results confirm that the proposed scheme improves both the mean response time and the throughput of clusters compared to rival load balancing algorithms and prevents clusters being overloaded even when request rates are beyond the cluster capacity.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1996-2002
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• 2007

The redox behavior of a [Ni6(μ3-Se)2(μ4-Se)3(Fe(η 5-C5H4P-Ph2)2)3] (= [Ni-Se-dppf], dppf = 1,1-bis(diphenylphosphino) ferrocene) cluster was studied using platinum (Pt) and glassy carbon electrodes (GCE) in nonaqueous media. The cluster showed electrochemical activity at the potential range between +1.6 and ?1.6 V. In the negative region (0 to ?1.6 V), the cluster exhibited two-step reductions. The first step was one-electron reversible, while the second step was a five-electron quasi-reversible process. On the other hand, in the positive region (0 to +1.6 V), the first step involved one-electron quasi-reversible process. The applicability of the cluster was found towards the electrocatalytic reduction of CO2 and was evaluated by experiments using rotating ring disc electrode (RRDE). RRDE experiments demonstrated that two electrons were involved in the electrocatalytic reduction of CO2 to CO at the Se-Ni-dppf-modified electrode.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.166-171
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• 2023

Efficient energy management is a very important factor in sensor networks with limited resources, and cluster techniques have been studied a lot in this respect. However, a problem may occur in which energy use of the cluster header is concentrated, and when the cluster header is not evenly distributed over the entire area but concentrated in a specific area, the transmission distance of the cluster members may be large or very uneven. The transmission distance can be directly related to the problem of energy consumption. Since the energy of a specific node is quickly exhausted, the lifetime of the sensor network is shortened, and the efficiency of the entire sensor network is reduced. Thus, balanced energy consumption of sensor nodes is a very important research task. In this study, factors for balanced energy consumption by cluster headers and sensor nodes are analyzed, and a balancing distribution clustering method in which cluster headers are balanced distributed throughout the sensor network is proposed. The proposed cluster method uses multi-hop routing to reduce energy consumption of sensor nodes due to long-distance transmission. Existing multi-hop cluster studies sets up a multi-hop cluster path through a two-step process of cluster setup and routing path setup, whereas the proposed method establishes a hierarchical cluster routing path in the process of selecting cluster headers to minimize the overhead of control messages.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.316-328
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• 2023

In this study, the characteristics of nonpoint pollutant outflow and contribution rate of pollution in Songya-stream mainstream and tributaries were analyzed. Further, water pollution management and improvement measures for pollution-oriented rivers were proposed. An on-site investigation was conducted to determine the inflow of major pollutants into the basin, and it was found that pollutants generated from agricultural land and livestock facilities flowed into the river, resulting in a high concentration of turbid water. Based on the analysis results of the pollution load data calculated through actual measurement monitoring (flow and water quality) and the occurrence and emission load data calculated using the national pollution source survey data, the S3 and S6 were selected as the concerned pollution tributaries in the Songya-stream basin. Results of cluster analysis using Pearson correlation coefficient evaluation and Density based spatial clustering of applications with noise (DBSCAN) technique showed that the S3 and S6 were most consistent with the C2 cluster (a cluster of Songya-stream mainstream owned area) corresponding to the mainstream of Songya-stream. The analysis results of the major pollutants in the concerned pollution tributaries showed that livestock and land pollutants were the major pollutants. Consequently, optimal management techniques such as fertilizer management, water gate management in paddy, vegetated filter strip and livestock manure public treatment were proposed to reduce livestock and land pollutants.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1912-1918
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• 2006

Marine bacterium Hahella chejuensis KCTC 2396 simultaneously produced red antibiotic prodigiosin and undecylprodiginine. A complete set of the prodigiosin biosynthetic gene cluster has been cloned, sequenced, and successfully expressed in a heterologous host. Sequence analysis of the gene cluster revealed 14 ORFs showing high similarity to pig and red genes from Serratia spp. and Streptomyces coelicolor A3(2), respectively, and the gene organization was almost: similar to that of pig genes. These genes were named hap for Hahella prodigiosin, and determined to be transcribed as a single operon, by RT-PCR experiment. Based on the hap gene mutagenesis experiments and comparative analysis with pig and red genes, we propose a prodigiosin-biosynthetic pathway in KCTC 2396.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.67-77
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• 2007

In sensor networks, it is very important to refresh communication keys of sensors in a periodic or on-demand manner. To perform a dynamic key management efficiently, sensor networks usually employ cluster architecture and each CH (Cluster Head) is responsible for key management within its cluster. In cluster-based sensor networks, CHs are likely to be targets of capture attacks, and capture of CHs threatens the survival of network significantly. In this paper, we propose a periodical key refreshment scheme which counteracts against capture of CHs. First, the proposed scheme reduces the threat caused by compromise of CHs by forcing each CH to manage a small number of sensors and changing CH role nodes periodically. Second, the proposed scheme flings attackers into confusion by involving other nodes in a key establishment between BS (Base Station) and a CH. Our numerical analyses showed that the proposed scheme is more secure than other schemes and robust against compromise of CHs.

• Korean Journal of Human Ecology
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• v.12 no.4
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• pp.559-570
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• 2003

The focus of this research was concerned with studying lower body type for Korean adult males. To understand the features of men's lower body required to organize an optimal sizing system for men's tight-fit slacks, information from the measuring values based on research on the physical standard of the nation(l997) were summarized; in addition, a factor analysis and a cluster analysis among multivariate analyses were performed. In terms of the need for appropriate fit in motorcycle wear, basic lower body parts applying to each item had to be taken into consideration to enhance sizing suitability. In the case of the length of the lower limbs, the inclusion of protectors plays an important role in affecting sizing. The factors related to the lower body were defined as follows: Factor 1 was the vertical dimension of the lower body, Factor 2 was the horizontal dimension of waist and hip, Factor 3 was the horizontal dimension of the lower limbs, Factor 4 was the length of hips, and Factor 5 was the ankle height. The lower body part was also divided into 3 clusters. Cluster 1 referred to the smallest stature and skeleton structure among the 3 body types. Cluster 2 represented the biggest stature, with a thin lower limbs body type. Cluster 3 represented a medium stature but with a large skeleton structure of lower limbs, a muscular type. In conclusion, Cluster 2 appeared most in the 20s age groups, but Cluster 3 appeared most in each of the 30s, 40's, and 50's age groups.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.5
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• pp.959-976
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• 2023

This study participated in educational programs for young designers and received trainings in sewing technology through government and local government-supported projects led by a from a skilled craftsman. These initiatives aim to revitalize the Dongdaemun fashion cluster, which is currently experiencing stagnation. Our goal is to develop denim brands that reflect the unique regional characteristics stemming from the skilled sewing techniques and denim processes of the Changsin·Sungin regions, the production hubs supporting Dongdaemun, to discover solutions for revitalizing the local industry. For the research method, we collected data by actively participating in support projects related to the Dongdaemun fashion cluster. Additionally, we gathered data by conducting a theoretical review of the sewing industry in the Changsin·Sungin regions and the Dongdaemun fashion cluster. The research results include developing a denim brand collection-eight denim products-based on Changsin-dong's unique denim sewing technology and various denim washing processes acquired through the support project and regional characteristics. Overall, this study is meaningful in presenting a sustainable plan to revitalize the domestic sewing and manufacturing industry, focusing on the Dongdaemun fashion cluster. We achieved this by developing a denim brand that leverages the sewing and washing process technology and the unique regional characteristics of Changsin-dong.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.1
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• pp.17-33
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• 2023

Disasters in coastal regions are a constant source of damage due to their uncertainty and complexity, leading to the proposal of green infrastructure as a nature-based solution that incorporates the concept of resilience to address the limitations of traditional grey infrastructure. This study analyzed trends in research related to coastal disasters and green infrastructure by conducting a co-occurrence keyword analysis of 2,183 articles collected from the Web of Science (WoS). The analysis resulted in the classification of the literature into four clusters. Cluster 1 is related to coastal disasters and tsunamis, as well as predictive simulation techniques, and includes keywords such as surge, wave, tide, and modeling. Cluster 2 focuses on the social system damage caused by coastal disasters and theoretical concepts, with keywords such as population, community, and green infrastructure elements like habitat, wetland, salt marsh, coral reef, and mangrove. Cluster 3 deals with coastal disaster-related sea level rise and international issues, and includes keywords such as sea level rise (or change), floodplain, and DEM. Finally, cluster 4 covers coastal erosion and vulnerability, and GIS, with the theme of 'coastal vulnerability and spatial technique'. Keywords related to green infrastructure in cluster 2 have been continuously appearing since 2016, but their focus has been on the function and effect of each element. Based on this analysis, implications for planning and management processes using green infrastructure in response to coastal disasters have been derived. This study can serve as a valuable resource for future research and policy in responding to and managing various disasters in coastal regions.