• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.112-117
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• 2017

Interest in the development of renewable energy sources has been increasing over the past 10 years and the west coast of Korea is one of the most favorable regions for tidal power. Barrage type tidal power is representative of the experience of installation and operation of such power sources for long periods. However, future projects for barrage type energy sources are either delayed or closed due to their environmental impact. For this reason, we applied a new tidal power technology with minimized environmental impact to a candidate area in the west coast and then analyzed its feasibility. The new tidal power technology is called Dynamic Tidal Power (DTP). Because its verification is impossible both in the laboratory and field, a numerical model is used for the evaluation of DTP. This new technology produces tidal power by means of the phase difference caused by diffraction on both sides of a dike built tens of km away from the coast. Because DTP is theoretically able to almost double the tidal range, it is expected to be applicable to even a small tidal area. Unlike the barrage type, it has the advantage of reducing the environmental impact by not enclosing the sea water. The west coast of Korea is close to the metropolitan area and has a high tidal range and, thus, it is thought to be a suitable candidate for tidal power.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.120-127
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• 2020

This study examined the operation of a pressure gauge for measuring the internal pressure of a barrel. During the ammunition performance evaluation test, the internal pressure of the barrel was measured mainly using a copper crusher gauge. The internal piezo gauge (IPG) was used to replace the pressure measurement method, and the test results were analyzed to verify the operability of the IPG. For verification, actual shooting test data were used, and a t-test was used to analyze the results. The 155MM KH179 and M119 series propellant were used for the test equipment and ammunition. The results confirmed that there was no difference between the mean values of the two data results at a significance level of 5% for the data values between the copper gauge and the IPG. The use of the IPG was verified by replacing the existing copper gauge to measure the internal pressure of the barrel, and it was confirmed that the application width could be widened in terms of diversity of test measurement methods. Based on the results of this test, it can be applied to the compression measurement test of various types of ammunition in addition to the propellant charges.

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.217-225
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• 2002

The implantable middle ear(IME) system, which has good sound quality. superior sound intelligibility and wide frequency characteristics. can resolve the sound distortion and ringing effect by sound feedback at high gain operation those are the major problems of conventional hearing aid. In this paper, we have manufactured the IME system using differential electromagnetic transducer(DET) and verified the performance of the system by carrying out vibration and animal implanting experiment. The DET was manufactured using micro-machining technology and vibration experiment of the transducer was performed to inspect whether the transducer could vibrate in accordance with the applied sound signal or not. And the result of the loaded experiment using temporal bone sampled from cadaver showed that the transducer can drive the middle ear bone and transmit the signal to inner ear After the internal unit of IME system was implanted in a dog. the auditory brainstem response (ABR) test was carried out. The result of the test indicated the Proper behavior of the IME system in the living body From the results of the experiments, it is verified that the manufactured system ewll work well when it is applied to human and a basis of clinical experiment of IME system to real human hearing impaired was be arranged.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.217-226
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• 2019

Optimum engineering methods for bank protection were classified based on steepness of bank slope and an existence of waterfront facility in the floodplain, and a new concept of eco-hybrid rolling mat method which could be applicable for the unfitted cases with previously developed countermeasures was suggested in this study. The eco-hybrid rolling mat method can be constructed while maintaining the river environment and ecosystem that does not interfere with the ground and slopes, when bank erosion occurs, it is an economical and efficient construction method that can protect the revetment and the bank slope immediately. The developed eco-hybrid rolling mat method was verified for the designed structure, system, function and effect based on large-scale river experiments including field exposure and decomposition test. As a result, the normal operation and effect of the rolling mat ted under low and high velocity conditions were confirmed with respect to bank protection. The effect of bank erosion prevention was quantitatively validated by sediment concentration monitoring and analysis, and the product specification of the eco-hybrid rolling mat was presented based on the standardized mat applied in real-scale tests.

• Science of Emotion and Sensibility
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• v.21 no.1
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• pp.165-176
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• 2018

A demand for user's participation in the designing process, which is called the participation design, is increasing with social change. Practically, however, there is lack of researches on the improvement of the problem in actual design development and participation design effect. In order to understand the field-based participation design effect in view of user's change of awareness on participation design, this study carried out a survey on the change of awareness through a design workshop in which all stakeholders have participated on the subject of agricultural direct sales facilities as a part of participation design programs. Many references were reviewed first to understand the participation design principles and their current research trend. Next, the questionnaire was developed using an effectiveness verification model for an effective analysis. A design workshop as one of the participation design programs was organized and applied for the field response. In order to analyze the effect, the survey on participants' change of awareness was carried out before and after the program. The survey questionnaires were about motivation, knowledge, recognition, function, and participation and asked the design study graduates. The participation design effect was supplemented by additional open questions. As a consequence, the participants in the participation design program showed the noticeable effect in knowledge and function about the agricultural direct sales facilities. It was found that they were also highly satisfied with the participation design result and they recognized an importance of collaboration. This study also showed that a sufficient time schedule considering agricultural village life should be given for a smooth operation of the program and also a working environment is necessary for designing work.

• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.15-32
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• 2020

Increasing uncertainties in the technological innovation environment and increasing technology competition also present new challenges in terms of industrial technology security. Therefore, the purpose of this study was to identify the direction of policy change necessary for the improvement of related policies in the future by examining the importance and implementation of the government's industrial technology security support policies for small and medium-sized enterprises engaged in industrial technology innovation activities. As a result of the analysis, first of all, small and medium-sized enterprises that responded to the government's industrial technology security support policy were perceived to be less performing than the importance of the program. These results can be said to mean that selective budget expansion for related policy programs may be necessary, along with efforts to improve the quality of each program. Second, an analysis of the differences in group recognition between new technology certification firms and industrial technology verification(certification) companies showed that significant differences exist between groups for the program. These results suggest that more effective operation of the relevant policies may require policy enforcement in consideration of the level of security and will of each company in industrial technology, as much as the quantitative characteristics of the entity. This study is meaningful in providing the necessary policy directional basic information for the design and execution of more specific and effective industrial technology security policies by presenting empirical research results that domestic small and medium-sized enterprises are aware of about the government's industrial technology security policies.

• Spatial Information Research
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• v.22 no.5
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• pp.65-75
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• 2014

Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers' waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.6
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• pp.37-48
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• 2005

The efficiency of power supply circuits such as DC-DC converters and batteries varies on the trend of the power consumption because their efficiencies are not fixed. To analyze the efficiency of power supply circuits, we need the temporal behavior of the power consumption of the loads, which is dependent on the activity factors of the devices during the operation. Since it is not easy to model every detail of those factors, one of the most accurate power consumption analyses of power supply circuits is measurement of a real system, which is expensive and time consuming. In this paper, we introduce an active load emulator for embedded systems which is capable of power measurement, logging, replaying and synthesis. We adopt a pattern recognition technique for data compression in that long-term behaviors of power consumption consist of numbers of repetitions of short-term behaviors, and the number of short-term behaviors is generally limited to a small number. We also devise a heterogeneous structure of active load elements so that low-speed, high-current active load elements and high-speed, low-current active load elements may emulate large amount and fast changing power consumption of digital systems. For the performance evaluation of our load emulator, we demonstrate power measurement and emulation of a hard drive. As an application of our load emulator, it is used for the analysis of a DC-DC converter efficiency and for the verification of a low-power frequency scaling policy for a real-time task.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.64-77
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• 2015

An effective method for produce munitions effectiveness data is to calculate weapon effectiveness indices in the US military's Joint Munitions Effectiveness Manuals (JMEM) and take advantage of the damage evaluation model (GFSM) and weapon Effectiveness Evaluation Model (Matrix Evaluator). However, a study about the Range Safety that can be applied in the live firing exercises is very insufficient in the case of ROK military. The Range Safety program is an element of the US Army Safety Program, and is the program responsible for developing policies and guidance to ensure the safe operation of live-fire ranges. The methodology of Weapon Danger Zone (WDZ) program is based on a combination of weapon modeling/simulation data and actual impact data. Also, each WDZ incorporates a probability distribution function which provides the information necessary to perform a quantitative risk assessment to evaluate the relative risk of an identified profile. A study of method to establish for K-Range Safety data is to develop manuals (pamphlet) will be a standard to ensure the effective and safe fire training at the ROK military education and training and environmental conditions. For example, WDZs are generated with the WDZ tool as part of the RMTK (Range Managers Tool Kit) package. The WDZ tool is a Geographic Information System-based application that is available to operational planners and range safety manager of Army and Marine Corps in both desktop and web-based versions. K-Range Safety Program based on US data is reflected in the Korean terrain by operating environments and training doctrine etc, and the range safety data are made. Thus, verification process on modified variables data is required. K-Range Safety rather than being produced by a single program, is an package safety activities and measures through weapon danger zone tool, SRP (The Sustainable Range Program), manuals, doctrine, terrain, climate, military defence M&S, weapon system development/operational test evaluation and analysis to continuously improving range safety zone. Distribution of this K-range safety pamphlet is available to Army users in electronic media only and is intended for the standing army and army reserve. Also publication and distribution to authorized users for marine corps commands are indicated in the table of allowances for publications. Therefore, this study proposes an efficient K-Range Safety Manual producing to calculate the danger zones that can be applied to the ROK military's live fire training by introducing of US Army weapons danger zone program and Range Safety Manual

• Plant Journal
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• v.10 no.2
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• pp.28-37
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• 2014

Recently, it is considered that environment and energy are critical issues all over the world. In power generation sector in Korea, almost power stations are constructed and operated as cogeneration plants in conformity with this trend. KDHC(Korea District Heating Corporation) goes one step further adopting renewable energy technology like heat pump using wasted heat for energy-saving and environment improvement. This study investigates the performance characteristics by the location of waste heat recovery heat pumps of 5 Gcal/h capacity in 150 MW-class Gwang-gyo cogeneration plant using commercial software 'THERMOFLEX'. Prior to analysis, the simulations are performed with actual operation data, and then the validation of simulations is verified by checking the error within 2%. After verification, the simulations are carried out with 3 locations and the effect on electrical power output and heat output is analyzed. As a result, overall efficiency of cogeneration plant is the highest in the case of heat pump located before DH(District Heating) Heater because of the largest increase of heat output despite of decrease of electrical power output.