• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.266-274
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• 2020

This paper reports a means of improving the abnormal noise of light tactical vehicles (LTVs) by applying a vehicle fitting type generator (hereinafter called generator). LTVs are classified as having generators, and there are no differences in the noise level. On the other hand, quality improvement was performed in response to unpleasant noise felt by the user (hereinafter called abnormal noise) during vehicle operation. To improve the quality, the generator mounting structure and the phenomenon of the vehicle in the problem were identified. Through this, it was confirmed that the noise caused by the generator installation was the rattle noise. Rattle noise at the engine driving system is normally caused by the transfer of irregular torque generated by the engine power stroke and the backlash by the spline-serration fitting structure between the engine coupler and rotor assembly in a generator. Therefore, this study established an improvement plan to apply a damper coupler to solve the cause of the abnormal noise. Regarding the improved establishment method, the improvement effect was confirmed from the influence of the irregular torque of the engine, noise level, dynamic characteristics analysis, and the endurance test of the parts.

• Journal of Environmental Impact Assessment
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• v.29 no.5
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• pp.363-376
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• 2020

Various policies and institutional efforts are being made for mature democracy and more sustainable administration of our society. In this respect, the importance of civic participation, considered essential in environmental impact assessment, has been consistently emphasized in the relevant theories and practices. Although various methods and forms of public participation are taking place in Korea, criticism is widely understood that collecting citizens' opinions in the decision-making process has become ineffective and formal. Starting from these issues, this paper seeks to learn lessons from the foreign cases in the international context. Extensive literature review was conducted to examine the meaning and objectives of public participation in EIA and the tactical principles. Based on this, the participatory systems and procedures in the United States, Britain, Germany, Japan, and Canada were critically reviewed, and the implications were derived through specific cases. The results are, first, the provision of specific public participation guidelines, second, the securing of transparency in the decision-making process, third, the expansion of procedural participation levels, and lastly, the guarantee of participation opportunities. This paper is meaningful as a basic study to enrich discussions on public participation in the domestic EIA hoping to help research through more diverse empirical cases in the future.

• Korea and Global Affairs
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• v.2 no.2
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• pp.5-40
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• 2018

The history of decentralization and autonomy is the result of the struggle for democracy against the authoritarian central government. Before the imminent law amendment, there are many tasks for decentralization and citizen autonomy. Therefore, decentralization and autonomy are not given on their own but they must be taken from authoritarian and centralist power group which possesses exclusive interests. The decentralization and autonomy now enters into the stage of development. In 1960, the April 19 Revolution opened the era of democratic local autonomy and it was abolished by the military coup of May 16, Now, the era of the reform of the decentralization are coming. Decentralization and autonomy will evolve from the stage of quantitative expansion to the stage of qualitative leap. This paper proposes that the revision of decentralization be the strategic maximum, and that the independence of the local government personnel rights be the tactical minimum. This paper insists that the independence of personnel right in the local government can be a link with law amendment for decentralization. Local autonomy and decentralization are the main subjects of the amendment. Above all, clarifying this is the subject and method of this study, and the scope of the study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.1
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• pp.106-113
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• 2002

In this paper, breakdown characteristics of pure Kr, Ar and $N_2$gas with gas pressure range were investigated, and the measured values were compared with those in Ar/$N_2$and Kr/$N_2$gas mixtures with pressure varying. Also, various characteristics with gas mixtures in practical incandescent lamps were investigated. Summarizing the experimental results, the breakdown voltages of $N_2$gas were increased than those of Kr and Ar gas with large molecular weight, and the breakdown voltage increased with gas pressure increasing. The breakdown voltages of Ar/$N_2$and Ar/$N_2$gas mixtures were decreased with decreasing the mixtures ratio of $N_2$gas, and corona inception voltage of Kr/$N_2$gas mixtures under non-uniform fields were increased than those of Ar/$N_2$gas mixtures. In case of tactical incandescent lamps, luminous and lifetime of Kr(70%)/$N_2$(30%) gas mixtures were increased about 94[lm] and 380[hr] than those of Ar(70%)/$N_2$(30%) gas mixtures. and injection pressure of gas mixtures with cooling temperature of 20[$^{\circ}C$] in incandescent lamps were increased about 13[%] than those with cooling temperature of 40[$^{\circ}C$].

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.353-360
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• 2016

The International Maritime Organization (IMO) has issued international standards for ship maneuverability and stability. These have been established to improve marine safety and influence the direction of research. The previous literature has been researched, but there are few studies on the relationship between ship maneuverability and stability. This study carried out a fundamental experiment to quantitatively evaluate that relationship. Radius of turn and maximum heel angle depending on changing were analyzed through a turning test using a free running model ship. The test results show the change tendency of decreasing turn radius and increasng maximum heel angle according to a GM decrease. A rough estimate equation is proposed to predict the change tendency on radius of turn and angle of maximum heel as GM decreases. Many ships can suddenly experience reduced GM due to unexpected reasons during sailing. The results in this study can be used as fundamental data to estimate a ship's tactical turn diameter and variable heel angle for steering as GM decreases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.1-7
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• 2020

In modern society, as technology has advanced and human life area has expanded, there has been an increasing demand for high-quality voice and video communications services without restrictions on time and place. In response to this demand, satellite communications systems that provide a wide range of communications and that offer multiple access are evolving day by day. In satellite communications systems such as Digital Video Broadcasting - Return Channel Via Satellite (DVB-RCS) and Warfighter Information Network-Tactical (WIN-T), the multi-frequency time division multiple access (MF-TDMA) demand assigned multiple access (DAMA) scheme is used for efficient resource allocation. In this scheme, since the satellite terminals periodically request resources from the network controller, and the network controller dynamically allocates resources, it is necessary to arrange resource allocation information from time to time. Shortening of the alignment time is a more important factor in a satellite communications system in which a long transmission delay occurs due to long-distance transmission and reception. In this paper, we propose a sorting algorithm variable-selection scheme that shortens the sorting time by cross-selecting the sorting algorithm based on a threshold value, while setting the number of frames in the MF-TDMA DAMA satellite communications system as the threshold value.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.666-673
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• 2013

This paper proposes the performance evaluation test of attitude heading reference system (AHRS) suitable for small high speed autonomous underwater vehicle(AUV). Although IMU can provides the detail attitude information, it is sometime not suitable for small AUV with short operation time in view of price and the electrical power consumption. One of alternative for tactical grade IMU is the AHRS based micro-machined electro mechanical system(MEMS) which can overcome many problems that have inhibited the adoption of inertial system for small AUV such as cost and power consumption. A cost effective and small size AHRS which incorporates measurements from 3-axis MEMS gyroscopes, accelerometers, and 3-axis magnetometers has been developed to provide a complete attitude solution for AUV and the attitude calculation algorithm is derived based the coordinate transform equation and Kalman filter. The developed AHRS was validated through various performance tests as like the magnetometer calibration, operating experiments using land mobile vehicle and flight motion simulator (FMS). The test of magnetometer calibration shows the developed MEMS AHRS is robust to the external magent field change and the test with land vehicle proves the leveling error of developed MEMS AHRS is below $0.5^{\circ}/hr$. The results of FMS test shows the fact that AHRS provides the measurement with $0.5^{\circ}/hr$ error during 5 minutes operation time. These results of performance evaluation tests showed that the developed AHRS provides attitude information which error of roll and pitch are below $1^{\circ}$ and the error of yaw is below $5^{\circ}$ and satisfies the required specification. It is expected that developed AHRS can provide the precise attitude measurement under sea trial with real AUV.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.88-96
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• 2011

Underwater acoustic communication is applicable in various areas, such as ocean data collection, undersea exploration and development, tactical surveillance, etc. Thus, robot control system construction used for underwater-robot like AUV or ROV is essential in these areas. In this paper, we propose the Message Merging MAC($M^2$-MAC) protocol, which is suitable for real time robot control system, considering energy efficiency in important parts of underwater acoustic sensor network constitution. In this proposed MAC protocol, gateway node receives the data from robot nodes according to the time slots that were allotted previously. And messages delivered from base-station are generated to one MAC frame by buffering process. Finally, generated MAC frames are broadcasted to all robot nodes in the cluster. Our suggested MAC protocol can also be hybrid MAC protocol, which is successful blend of contention based and contention-free based protocol through relevant procedure with Maintenance&Sleep (M&S) period, when new nodes join and leave as an orphan. We propose mathematical analysis model concerned about End-to-End delay and energy consumption, which is important factor in constructing real-time robot control system. We also verify the excellence of performance according to comparison of existing MAC protocols with our scheme.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.225-235
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• 2020

The Korean government is attempting to promote technology-based start-ups and venture firms that can lead to new national growth engines being developed. Although government support policies focus on improving survival rates, strategic tools for sustainability management based on a continuing company's assumption are also relevant. Previous studies indicate corporate social responsibility (CSR) as an important strategic tool for the management of corporate sustainability. This research is an exploratory study that seeks to empirically analyze the applicability of such CSR to venture firms. Existing previous studies have been carried out by large companies and surveys, and there are limitations that do not reflect the characteristics of companies. To complement the shortcomings of previous studies and propose practical consequences, this study conducted an empirical analysis using raw data from government approval statistics to identify the growth stages of venture firms. Using the 2018 Survey of Korea Venture Firms, we identified the growth stages of domestic venture firms and used the data envelopment analysis (DEA) to investigate the effect of CSR activities on managerial efficiency. The analysis found that CSR during start-up and early growth cycles did not affect managerial performance. The organization that conducted enthusiastic CSR activities performed better than those that did not perform CSR activities since the rapid growth era. Ultimately, the scale efficiency of venture business was the highest from the rapid growth era when the CSR was not done. This study is a pioneering study that found that after the period of high growth, venture firms' CSR activities can affect managerial performance. Therefore, it is important to advise applicable policies and business decision-makers that CSR practices can be a tactical resource for improving performance of management.

• The Journal of the Korea Contents Association
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• v.10 no.11
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• pp.169-179
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• 2010

In these days, space design is evolving to the mixed reality space where fused on-line and off-line. But, standard and measure of mixed reality space has not been suggested and there has been little research about media environment and expression method as a mixed system either. That's why here I suggest four media environments and their characteristics that act not only as a critical point in the mixed reality space based on ubiquitous technology but also as a standard for spatial discerning. 1) Real space that is a media environment only seen by human visual and tactical sense is evolving using expression methods like new materials based on digital technology and LED. 2) Augmented reality space is a media environment using information instruments is expressed with diverse 2D and 3D contents. 3) Cyber Space is a environment depends totally on media instruments is produced by perfect graphic information without any spatial and physical limitations. 4) Augmented cyber space is realized only through the displays in cyber studio and is a space where real objects and graphic information are mixed. Depending on the purpose of the experience, media environment and expressional characteristics of mixed reality space can be fused, blended, and mixed, and that can be realized to the intelligent information space where one can experience without spatial, visual, informational limitations. In the future, studies on physical characteristics of contents according to the media environment characteristics are necessary.