• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.313-316
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• 2001

At the end of 1999, the TeraCluster project in the KISTI Supercomputing Center was initiated to explore the possibility of PC clusters as a scientific computing platform to replace the Cray T3E system in KISTI by the year 2002. In order to understand whether an application is scalable to tera-flops sized cluster system, running test is inevitable. Extensive performance tests using well-known benchmarking codes with real applications' characteristics in them were carried out with different combinations of CPUs, system boards, network devices. The lessen learned shows the relationships between system performances and varied applications' different needs resulting in promises of How-Tos in building large scale cluster system. The 64/16 node clusters with Alpha EV6(466MHz), Pentium III(667 MHz) i inter-node network of Fast Ethernet. SCI[1] and Myrinet[2] were evaluated. More detailed specifications of the Linux clusters are described in Table 1.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.61-70
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• 2019

Recently, research and development for next-generation mobile communication and short-range wireless communication has begun worldwide along with the provision of commercial services of 5G mobile communication technology. In response to this trend, the THz band has attracted considerable attention as a frequency band for transmitting 100 Gbps of large-capacity wireless data. For communication in the THz band, research and development of approaches based on photonics and electronics is being actively performed; the configurations, characteristics, and performances of these two methods for THz transmission have been seriously examined. Among them, we reviewed the technical issues in implementing THz wireless transmission technology using photonics technology. We also introduced the Electronic and Telecommunications Research Institute's (ETRI) development of photonics-based THz short-range transmission technology starting from 2019 and including some initial results. In the near future, 100 Gbps high-capacity wireless data transmission technology utilizing photonics technology is expected to be commercially available and applied to various applications, such as 3D hologram transmission, uncompressed large capacity medical data transmission, and multiple augmented reality/virtual reality (AR/VR).

• Journal of the Society of Naval Architects of Korea
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• v.31 no.2
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• pp.65-77
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• 1994

This paper presents a derailed application procedure of the linear quadratic(LQ) theory for a SWATH heave and pitch control. A time domain model of coupled, linear time-invariant second order differential equations is derived from the frequency response model with the frequency dependent added mass and damping approximated as constant values at the heave natural frequency. Wave exciting forces are modeled as a sum of sinusoids. A systematic selection procedure of state and control weighting matrices is presented to obtain good transient behavior and acceptable fin movement. The validity of this controller design process is throughly investigated by simulations both in time domain and frequency domain and singular value plots of transfer function matrices. The finally designed control system shows good overall performances revealing that the applicability of the present study is proved successful.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.248-261
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• 2021

Scientific and technological performances (e.g., patents and publications) made through R&D play a pivotal role for national economic growth. National governments encourage academia-industry cooperation and thereby pursue continuous development of science technology and innovation. Increasing R&D-related investments and manpower are crucial for national industrial development, but evidence of poor performance in business performance, efficiency, and effectiveness has recently been found in Korea. This study evaluates performance efficiency of the 6T sector (Information Technology, Bio Technology, Nano Technology, Space Technology, Environment Technology, Culture Technology), which is considered a high-potential promising industry for the next generation growth and currently occupies two thirds of the national R&D projects. The study measures the relative efficiency of R&D in a comparative perspective by employing the Data Envelopment Analysis (DEA) method. The result reveals overall low efficiency in basic R&D (0.2112), applied R&D (0.2083), development R&D (0.2638), and others (0.0641), confirming that economic performance and efficiency were relatively poor compared to production efficiency. Efficient R&D needs policy makers to create strategies that can increase overall efficiency by improving productivity performance and quality while increasing economic performance.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.11
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• pp.585-594
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• 2016

Information system development projects are increasingly enlarging in size and are becoming more complex in the development environment. The traditional approaches for the development of information system, however, haven't shown the expected performances in the management for them and many researchers have been trying to find a new approach for overcoming this challenges. And one of the new approaches is the PMO and it is introduced to solve the problems of project management and the related organizational, technical, and administrative problems. This study attempted to find the efficient information system establishment plan. In particular, this study wants to research the practicality of PMO and the detailed utilization plans. As a result, this study proposes the structure of project implementation, the requirements, the direction of the basic system design, the scope of system development, and the budgeting for the systems. It is expected to contribute the successful implementation of the project.

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.100-104
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• 2008

Titanium sheet metal substrates used in thin film batteries were wet etched and their surface area was increased in order to increase the discharge capacity and power density of the batteries. To obtain a homogeneous etching pattern, we used a conventional photolithographic process. Homogeneous hemisphere-shaped wells with a diameter of approximately $40\;{\mu}m$ were formed on the surface of the Ti substrate using a photo-etching process with a $20\;{\mu}m{\times}20\;{\mu}m$ square patterned photo mask. All-solid-state thin film cells composed of a Li/Lithium phosphorous oxynitride (Lipon)/$LiCoO_2$ system were fabricated onto the wet etched substrate using a physical vapor deposition method and their performances were compared with those of the cells on a bare substrate. It was found that the discharge capacity of the cells fabricated on wet etched Ti substrate increased by ca. 25% compared to that of the cell fabricated on bare one. High discharge rate was also able to be obtained through the reduction in the internal resistance. However, the cells fabricated on the wet etched substrate exhibited a higher degradation rate with charge-discharge cycling due to the nonuniform step coverage of the thin films, while the cells on the bare substrate demonstrated a good cycling performance.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.519-524
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• 2017

The present study investigated the impacts of mating age of gilts (A1, < 230 days; A2, 230 - 249 days and A3, $250{\leq}days$) on reproductive performance and litter size of sows at farrowing to weaning. A total of 102 crossbred gilts ($Yorkshire{\times}Landrace$; average days old, 90 days) were purchased from a commercial breeding company. After identification of third estrus, the gilts were artificially inseminated using semen of Duroc boars. Pregnant pigs were allotted to one of three groups including A1, A2, and A3. Experimental diets and water were fed ad libitum during each experimental period which included the first, second, and third parities. Backfat thickness (BFT) of sows was higher in A3 at farrowing in the first parity than in others. At weaning time in the second parity, sows in A3 group showed a numerically higher BFT than those in A1. There was no effect of mating age on the total number of piglets born and total weaned piglets. There was a tendency to decrease the wean-to estrus-interval in the first parity as age increased at mating. Results obtained in the present study indicate that the first mating age does not affect the subsequent parites' reproductive performance; however, weaned to estrus interval tended to decrease in A2 at the first parity.

• Journal of Korean Society of Rural Planning
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• v.21 no.2
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• pp.103-114
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• 2015

The comprehensive rural village development projects (CRVDP) have been carried out as the core one of the rural development schemes in Korea since 2004. CRVDP included the various rural experience programs to increase rural income and in order to promote rural community development in the project area. This study analyzed the operating management conditions, types and characteristics of the rural experience programs targeting the 168 CRVDPs have been completed so that the recommendations and lessons which were found the usefulness, challenges and improvements to the CRVDP can be provided to be better the same kinds of rural development projects. We identified the relationships between performances such as increasing village income and utilization of rural amenity resources to the CRVDP and operational management types of the rural experience programs as well. Employing principle component analysis and cluster analysis technique, this study found 5 clusters of rural experience programs among 168 CRVDPs. The results of analysis of variance indicated that there were significant the mean differences between clusters such as the utilization of rural amenity resources(0.01), income of rural experience programs(0.1). According to the result of the Chi-squire test, there was very significant differences between internet homepage operation and clusters(0.01). Finally, the analysis of covariance about the income of rural experience programs showed that there were significant the mean differences between clusters(0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.3
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• pp.282-286
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• 2013

This study was conducted to compare extruded pellets (EP) and soft extruded pellets (SEP) with a raw fish-based moist pellet (MP) diet on the growth and flesh quality of Korean rockfish Sebastes schlegeli. Three groups of 20,000 fish (initial mean weight 133 g) per net-cage ($6{\times}12{\times}7m$) were fed commercial EP, SEP or MP for 16 months. The survival of fish fed SEP was higher than those of fish fed EP or MP. The highest growth performances were observed in the mean weight gain, total weight gain, and feed efficiency of fish fed MP, followed by those fed EP and SEP. Among the fish fed on extruded pellets, the total weight gain of fish fed SEP was higher than that of those fed EP, while fish fed EP grew faster than those fed SEP. No notable differences in body composition, sensory scores or textural properties of the dorsal muscle were observed in fish fed on EP, SEP or MP. Thus, it is suggested that extruded pellets, rather than raw fish-based moist pellets, could be fed to Korean rockfish without compromising flesh quality.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.423-428
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• 2004

The development of a compact and high performance MWIR thermal imaging sensor based on the SOFRADIR 320${\times}$240 element IRCCD detector is described. The sensor has 20 magnification zoom optics with the maximum 40$^{\circ}$${\times}$30$^{\circ}$ of super wide field of view and 7.6 cycles/mrad of resolving power with the operation of attached micro-scanning system. In order to correct nonuniformities of detector arrays, we have proposed a multi-point correction method using defocusing of the optics and we have acquired the highest quality images. The MRTD of our system shows good results below 0.05K at spatial frequency 1 cycles/mrad at narrow field of view. Experimental data and obtained performances are presented and discussed.