• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.194-202
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• 2008

In this study, we investigated the tribology behaviour of two different bearing materials. One of these alloys content is Cu(90)-Sn(10) alloy and is widely used in the automotive industry.The other is Al alloy. This bearing content is Al-Sn-Si-Cu. Therefore, it is required to study on the lublicating characteristics of bearing according to different materials. In this study, compressor bearings made by respectively "PTFE solid lubricant" and "AI alloy with superior load carrying capacity, rubbing and impact endurance", have gone through journal bearing test. Lubrication and abrasion characteristics are evaluated by analyzing the material characteristics of a scroll compressor bearing bush. The AI alloy bearing showed the most excellent lubrication and abrasion characteristics than Cu-Sn alloy under high load condition.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.243-253
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• 2011

This paper aims to examine the moderate effects of Client's Organizational Character on the relationships between Consulting Service Quality and Business Performance. To accomplish these purposes, The questionaries of 192 were inspected to the CEO or PM having consulting experience at the companies in Daegu and kyoung-buk. First, Consulting Service Quality presented a meaningful result(+) with the Business Performance. Second, Consulting Service Quality have differential influence on Business Performance by Client' s Organizational Character.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.59-71
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• 2013

Cloud service (Amazon Web Services, etc.) to take advantage of the growing global competitiveness of small and medium companies with online services (eg Zynga, paprika wrap) are strenthening the growing global competitiveness by taking advantage of cloud utilization, and financial market analysis services by cloud use have appeared, but the domestic company's cloud still staying in the low-level. SMEs in Korea IT infrastructure needs as well as commercial services such as simulation, test environment configuration, to perform tasks that require a step-by-step in the product development process, which requires different IT Infrastructure Outsourcing workforce commitment, according to the rapid changes in the size of the organization's efficient IT infrastructure such as cloud services because of the lack of capacity to respond to a sudden demand for IT measures required.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.99-112
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• 2015

Drones are more formally known as unmanned aerial vehicles without a human pilot aboard. Its flight is controlled either autonomously by onboard computers or by the remote control of a pilot on the ground. This research aims to analyze market trends and technological developments of drones, use cases and constraints of drones in the cultural industries take advantage of the possibility of future drones. Drones are looking for broadcasting, movie, theater, games, toys drones and racing games in a variety of cultural industry. The biggest problem of drone shall provide penalties for breaches of privacy and security issues in the debate. Drones performances are required such as battery capacity and compactness because of the technical limitations. The drones are expected to be used in various fields such as journalism drone, performance tools, augmented reality games, kidult culture. The drones can create a new cultural industry market such as the combination of robotics and drone journalism, drone crowded theater, utilizing drones character games, racing games etc. In conclusion, drones help reduce manpower, time and costs dramatically and will contribute to creating added value in the cultural industries.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.47-53
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• 2014

LTE-Advanced is the evolved version of LTE which is currently in progress at the 3GPP. At present, as the number of smart phone users is rapidly increasing, the demand for ever more capacity is driven largely by video usage and high quality data communication and so on, this let more researchers study about LTE-A all over the world. LTE-A aims to achieve improved service and communication quality over 3G system at the aspect of throughput, peak data rate, latency, and spectral efficiency. Among various features in LTE-A, the multi-user MIMO(MU-MIMO), in which the base station transmits several streams to multiple receivers, has expected to give better quality for system. In this paper, we investigate performances of various types of downlink receivers with fixed number of antennas. we first review the development process from LTE to LTE-A. Second we introduce TM9 which is adopted in Rel.10 for MU-MIMO system, including the MU-MIMO system model and the explanation on the algorithm used in system. We also have brief introduction about sub-blocking in turbo decoding, finally we compare the performance between the uncoded case and coded case which is using turbo encoding.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.9-17
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• 2019

Sun power generation systems which use large capacity centralized inverters have loss of power generation due to cloud and building shadows, pollution, cell deterioration, etc. To minimize loss of power generation, decentralized solar power systems using multiple micro-inverters are being proposed as an alternative. A distributed solar power system consisting of a system-connected system uses power line communication to collect data from the micro-inverters. Power line communication has the advantage of using power lines without separate lines for data transmission, but in distributed solar power generation systems that use a large number of micro-inverters, the bit error rate is less reliable due to the phenomenon caused by limited transmission power, high load interference and noise, variable signal attenuation, and impedance characteristics. So we proposed wireless intelligent controller for micro-inverter that is used to build distributed solar power systems. and we design and implement that. Further, the proposed wireless intelligent controller for micro-inverter was used to establish a small-volume solar power plant to check its function and operation.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.309-315
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• 2016

The node mobility in the wireless mobile network environment increases the energy consumption. This paper proposes a CNMA (cluster-based node management algorithm) to reduce the energy consumption caused by node mobility, and to prolong the life cycle for cluster member nodes. The proposed CNMA traces the mobility for nodes between cluster header and member, and it analyses the energy capacity as monitoring periodically their relationship. So, it makes a division and merges by analysing the state transition for nodes. This paper is to reduce the energy consumption due to the node mobility. The simulation results show that the proposed CNMA can efficiently control the energy consumption caused by mobility, and it can improve the energy cycle.

• Journal of Digital Convergence
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• v.3 no.1
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• pp.89-113
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• 2005

The primary purpose of this study is to suggest the governmental strategies for enhancing the capacity of the culture technology industries. By reviewing the past relationships between the government and industry in the process of industrialization, we have arrived at some of the lessons about 'positive' or 'negative' effects on the relationships. The newly revised government and high-technology-based industry relations should be reformed in order to make the industries efficiently operated and competitive especially internationally. We have suggested a conceptual framework for the relationship by considering the policy community in consideration of the characteristics of the industries. The policy community is consisted of four dimensions. each of which, we considered were specifically, (1) research institutes for collecting data, market analysis, and gathering informations for the industries, (2) financial institutions, (3) professional groups for advising and sharing the technologies to the industries, and (4) education institutes for providing skilled personnels. Because these policy community does not effectively interrelate each other, we suggested that government should play pivotal roles in connecting these four dimensions of the policy community. The policy networking is necessary for the industries to be more effectively work together. The roles of government then provide some of the ways in which the policy community working interactively. By way of conclusion, we suggest some of the ways in which the government make the industries much more productive and competitive in the world markets.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.292-297
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• 2008

Various types of refrigerators become popular in the market such as a common refrigerator, kimchi refrigerator and wine cellar. It is required to develop a multi function refrigerator which has different purposes in each evaporator. In this study, the performance of a multi type refrigerator system, which consists of one machine room and three evaporators, was measured in a bench type multi refrigerator. The multi type refrigerator system was tested by varying the number of refrigerator cabinet, refrigerant charge amount, temperature condition. Based on experimental data, the multi type refrigerator showed better performance than the conventional refrigerator(single type) At the same external load condition, the COP of the multi type refrigerator was $1.22{\sim}1.29$, but the COP of the single type refrigerator was 1.0.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.93-110
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• 2015

The purpose of this study is to identify the role of T-shaped skill between customer/supplier network and innovation performance of firms. To manage effectively the relationship between collaborative firms, firms need to have a prior related knowledge. The premise of absorptive capacity is that the organization needs prior related knowledge to recognize, assimilate, and apply new knowledge. In this context, T-shaped skill facilitates the learning of new related knowledge. The skill is thus a critical component of innovative capabilities. We found that T-shaped skill plays a mediating role in the relationship between networks and innovation performance. The conclusions and implications are discussed.