• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.6 s.312
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• pp.34-42
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• 2006

As art analytic method to uncover interesting patterns hidden under a large volume of data, data mining research has been actively done so far in various fields. However, current state-of-the-arts in data mining research have several challenging problems such as being too ad-hoc. The existing techniques are mostly the ones designed for individual problems, so there is no unifying theory applicable for more general data mining problems. In this paper, we address the problem of classification, which is one of significant data mining tasks. Specifically, our objective is to evaluate radial basis function (RBF) model for classification tasks and investigate its usefulness. For evaluation, we analyze the popular Monk's problems which are well-known datasets in data mining research. First, we develop RBF models by using the representational capacity based learning algorithm, and then perform a comparative assessment of the results with other models generated by the existing techniques. Through a variety of experiments, it is empirically shown that the RBF model has not only the superior performance on the Monk's problems but also its modeling process can be controlled in a systematic way, so the RBF model with RC-based algorithm might be a good candidate to handle the current ad-hoc problem.

• KSBB Journal
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• v.14 no.5
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• pp.621-627
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• 1999

A food waste composting apparatus of 450 L was designed for and tested with changing conditions of inlet air flow rate, agitation and inoculation. Agitation was done twice per day for 5 min and inlet air flow rate was set as 22.7 L/min for RUN 1. For RUN 2 and RUN 3, agitation was continuous, and inlet air flow rate was changed frequently as 10 L/min, 15 L/min and 20 L/min in order to maintain temp. above 5$0^{\circ}C$, and the concentration of $O_2$over 7 mol%. The compost of RUN3 was inoculated with 10 wt% of accomplished compost, and it was compared with RUN 1 and 2 to show the effect of inoculation. The composting rates of RUN 2 and RUN 3 were faster than that of RUN 1, because agitation was continuous and temperature was controlled in RUN 2 and RUN 3. Inoculated RUN 3 was better than RUN 1 and RUN 2 in the concentrations of $CO_2$and reduction of volatile solids. while the effect of inoculation on C/N ratios, pH change and the numbers of microoragnisms was not clearly appeared.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.79-92
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• 2011

In this study, wave pressure of short-period gravity waves and tsunami acting on the upright section of the horizontal-slit type caisson placed on the impermeable or permeable seabed, which is a well-known permeable breakwater with a good wave controlling ability, are investigated via numerical simulations. Further, the permeable seabed was modeled as the porous media with porosity of 0.4. Using the numerical results, the effects of the seabed conditions on the wave pressure on the front wall and inside wall of the chamber have been studied. In the numerical simulations, short-period gravity waves and tsunami(solitary wave or bore) with the same amplitude to the gravity wave are considered. A numerical wave tank is used, which is able to consider a gas-liquid two-phase flow in the same calculation zone. Numerical results show that the wave pressure of the tsunami was 3~5 times higher than the short-period gravity waves acting on the front wall and it was 2~4 times higher than the short-period gravity waves acting on the inner wall.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.577-582
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• 2016

This Study focused on the development of SMPS (Switching Mode Power Supply) to supply the constant votage and current nevertheless LED fluorescent Light generated the electric noise (with Harmonics) and Inrush current at instant time of turn-on and off. Recently, according to the Green policy in government, the LED fluorescent Lighter showed the rapidly increasing tend as indoor and outdoor Lighter. But, because of costs, LED fluorescent Light not considered and neglected the following items; power factor, efficiency, Harmonics and Inrush current. So, we are developed the SMPS about 3 key issues as follows: 1st, power factor and efficiency is 85%. 2nd, the switching noisy by harmonic is minimized. 3rd, the Inrush current at turn on and off time is reduced the minimum 0.3 A after $100{\mu}sec$ on turnon time. The proposed SMPS adjusted by LNK 409 driver (included the high frequency modulation function). Although, the developed SMPS maintained the about 85% of power factor and efficiency. but, the SMPS must be generated low heat by the variation of minute load current at switching timing. To improve the above weak point, the developed SMPS have the feedback monitoring circuit between input side and output side to maintain the power factor and efficiency. Also, we are studied the time-constant of control circuit to output the constant voltage and current nevertheless the load disturbance of LED lighting. The LED fluorescent Light of 46W is checked the above items.

• Journal of KIISE:Information Networking
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• v.35 no.6
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• pp.521-528
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• 2008

Such conventional maritime communication technologies as radio have short some comings in their transmission quality. It can be overcome by wireless channels provided by satellites such as INMARSAT, which nevertheless suffer from the high costs. In this paper, we propose a novel technology resolving the above problems, featuring in the establishment of maritime communication networks with multi-hop structures. The inter vessel and ship-to- shore networks previously modeled after MANET are remodeled by SANET (Ship Ad Hoc Networks) in the present work. Fan-shaped Search Zone Routing (FSR) protocol also is presented, which utilizes not only static geographical information including the locations of ports and the navigations of courses but also the unique characteristics of ships in terms of mobile nodes. The FSR finds the fan-shaped search zone on which the shortest path is located. The performance of LAR protocol is compared with that of FSR in several ways. First, FSR does not make use of a type of control packets as beaconing data, resulting in a full utilization of the bandwidth of the wireless channels. Second, the delivery rate by the FSR is 100% for the fan-shaped search zone includes at least one route between source and destination nodes on its border line, where as that of LAR has been turned out to be 64%. Third, the optimality of routes searched by the FSR is on a 97% level. Of all, the FSR shows a better performance than LAR by about 50%.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1010-1026
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• 2004

The goal of product line engineering is to support the systematic development of a set of similar software systems by understanding and controlling their common and distinguishing characteristics. The product line engineering is a process that develops reusable core assets and develops a set of software-intensive systems from a common set of core assets in a prescribed way. Currently, many software development technologies are accomplished in context of product line. However, much of the product line engineering research have focused on the reuse of work products relating to the software's architecture, detail design, and code. The product lines fulfill the promise of tailor-made systems built specifically for the needs of particular customers or customer groups. In particular, commonality and variability play central roles in the all product line development processes. These must be treated already during the requirement analysis phase. Requirements in product line engineering are basis of software development just like as traditional system development engineering, and basis of deciding other core assets' property - commonalities and variabilities. However, it is difficult to elicit, analyze and manage correct requirements. Therefore, it is necessary to develop systematic methods which can develop and manage requirement as core asset, which can be stable in anticipative change and can be well adapted to unpredictable change. In this paper, we suggest a method of managing requirements as core asset in product line. Through this method, the reuse of domain requirements can be enhanced. As a result, the cost and time of software development can be reduced and the productivity can be increased.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.474-487
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• 2005

T-DMB (Terrestrial-Digital Multimedia Broadcasting) adopted MPEG-4 BIFS (Binary Format for Scene) Core2D scene description profile and graphics profile as the standard of video associated data service. By using BIFS, we can support to overlay objects, i.e. text, stationary image, circle, polygon, etc., on the main display of receiving end according to the properties designated in broadcasting side and to make clickable buttons and website links on desired objects. Therefore, a variety of interactive data services can be served by BIFS. In this paper, we implement real-time video associated data service system far T-DMB. Our developing system places emphasis on real-time data service by user operation and on inter-working and stability with our previously developed video encoder. Our system consists of BIFS Real-time System, Automatic Stream Control System and Receiving Monitoring System. Basic functions of our system are designed to reflect T-DMB programs and characteristics of program production environment as a top priority. Our developed system was used in BIFS trial service via KBS T-DMB, it is supposed to be used in T-DMB main service after improvement process such as intensifying system stability.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.126-127
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• 2003

원예산물의 밀도나 비중은 내부성분, 숙도, 내부붕괴(internal breakdown)와 같은 생리장해에 큰 영향을 받기 때문에, 밀도를 측정함으로써 내부품질에 대한 간접적인 판정이 가능하다고 보고되고 있다. 이 연구는 수박의 밀도와 당도와의 상관관계를 구명하고자 수행하였으며, 이를 위해 밀도의 실시간 계측시스템을 개발하였다. 현재 농산물의 밀도를 어느 정도 측정 정밀도를 유지하면서도 신속하게 측정할 수 있는 방법은 부력법(platform scale method)이다. 이 방법은 일정 크기의 용기에 물을 가득 채운 후 대상물을 담가 배제된 물의 무게를 측정하여 밀도를 환산한다. 그러나 매번 측정할 때마다 물을 보충하고, 물을 계량해야하는 등 전처리과정이 복잡하고, 1회 측정하는데 3~5분 정도가 소요되는 단점이 있고, 또한 인력 측정시 반복간 오차가 클 것으로 예상된다. 따라서 이 연구에서는 이 같은 계측상의 번거로움을 해소하고 동시에 신속하고 반복간 측정정밀도를 높일 수 있도록 수박 밀도 실시간 계측시스템을 설계 제작하였다. 시스템은 투명아크릴 수조($\Phi$400$\times$500), 로드셀, 프레임, 채반, 전기모터, 제어장치 및 컴퓨터로 구성하였다. 밀도 계측은 인장형 로드셀(CAS SB-20L, Max. 20kg)을 사용하여 대기중에서와 수박을 완전히 물에 잠기도록 한 후 무게를 각각 측정하여 밀도를 환산하였다. 밀도 계측시스템에 이용한 AD변환기의 분해능은 12bit이고, 수박의 무게 측정범위를 4~10kg로 가정할 때 20kg 로드셀의 1 digit(1bit)로 발생되는 오차는 0.09~0.24%FS 이었고, 따라서 이 시스템의 밀도 해상도는 0.001g/㎤이하였다. 시스템 평가를 위해 탄력이 좋은 고무풍선에 수박 크기 정도로 물을 채워 고정채반에 넣고 밀도를 측정한 결과 1.002g/㎤을 나타냈다. 즉 물의 이론밀도인 1g/㎤에 근접한 값을 보여 정확한 밀도 계측이 가능한 것으로 판단되었다. 또한 밀도 계측시스템의 측정 반복간 정밀도를 파악하기 위해 수박 6개를 임으로 선정하여 3반복 측정 시험한 결과, 측정표준편차가 0.001~0.004g/㎤로 해상도보다는 다소 높았으나 대체로 양호한 결과를 나타냈다. 수박 35개를 이용하여 개발 계측시스템과 사람이 직접 부력법으로 밀도를 측정 비교한 결과, 계측시스템에 의해 측정된 수박 밀도가 사람이 측정했을 때 보다 낮게 측정되었다. 수박의 외관인자(무게, 길이, 직경, 체적), 밀도와 당도의 상관관계 구명시험을 위해 원예연구소 시험포장에서 재배된 삼복꿀수박 총 74개를 공시재료로 하였고, 시험은 출수일별로 10~14개씩 수확하여 외관인자, 밀도, 당도를 각각 측정하고, 이들 인자들간의 상관관계를 구명하였다. 외관인자들간에는 높은 상관관계를 보였으나, 외관인자들과 밀도, 외관인자들과 당도, 밀도와 당도와는 매우 낮은 상관관계를 나타냈다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.891-901
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• 2016

By comparing test blasting data experimented in three layered-structure polymorphic grounds to a geological profile, influence of blast vibration with respect to uncontrollable ground characteristics was analyzed. Inefficient blast have been performed without sufficient verifications or confirmations because insufficiencies with regard to experiments and data of blasting engineering on the layered structures to be irregularly repeated clinker layer consisted of volcanic clastic zones. It is difficult to quantify N values of clinkers within test blasting region because they have diverse ranges, or coverages. An absolute value of attenuation coefficient N in a field, estimated by blasting vibration predictive equation (SRSD), are lesser than criteria of a design instruction, meaning that vibrations caused by blast can spread far away, and the vibrational characteristics of blasting test No.1, indicating relatively small values, inferred by the geological profile, pressures of gas by the explosion may be lost into a widely distributed clinker layers by penetrating holes resulted from blast into vicinity of clinker layers located in bottom of soft rock layers at the moment of blast. As a result, amounts of spalling rocks are decreased by almost half. Also, ranges of primary frequencies in the fields are identified as similar to those of natural frequency of typical structures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.41-49
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• 2011

In this paper, we propose an open protocol to be employed between a smart meter concentrator and a metering data collection server, and also evaluate its performance. Legacy concentrators performs the connection establishment and data gathering operations with DLMS/COSEM protocol standards. However, we note that there are no standardized protocols between the concentrator and the collection server, which inevitably conduces each commercial smart metering system to have its own proprietary protocol. In order to solve this problem, we propose an open protocol - Smart Meter Concentrator Control Protocol(SMCCP) by extending the existing standard protocol(DLMS/COSEM). The SMCCP can provide the proxy mode to enable efficient transmission between the concentrator and the data collection server. It also can support the relay mode to enable a direct communication between the data collection server and each far end smart meter. We also implement an emulator system and a protocol analyzer to provide its operation. In addition, we evaluate the session holding time and the link usage ratio in both relay and proxy modes with OMNET++ simulator.