• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.1 s.307
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• pp.17-26
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• 2006

This paper proposes a novel hidden Markov model (HMM)-based gesture recognition method and applies it to an HCI to control a computer game. The novelty of the proposed method is two-fold: 1) the proposed method uses a continuous streaming of human motion as the input to the HMM instead of isolated data sequences or pre-segmented sequences of data and 2) the gesture segmentation and recognition are performed simultaneously. The proposed method consists of a single HMM composed of thirteen gesture-specific HMMs that independently recognize certain gestures. It takes a continuous stream of pose symbols as an input, where a pose is composed of coordinates that indicate the face, left hand, and right hand. Whenever a new input Pose arrives, the HMM continuously updates its state probabilities, then recognizes a gesture if the probability of a distinctive state exceeds a predefined threshold. To assess the validity of the proposed method, it was applied to a real game, Quake II, and the results demonstrated that the proposed HMM could provide very useful information to enhance the discrimination between different classes and reduce the computational cost.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.125-132
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• 2014

Since frequent pattern mining was proposed in order to search for hidden, useful pattern information from large-scale databases, various types of mining approaches and applications have been researched. Especially, frequent graph pattern mining was suggested to effectively deal with recent data that have been complicated continually, and a variety of efficient graph mining algorithms have been studied. Graph patterns obtained from graph databases have their own importance and characteristics different from one another according to the elements composing them and their lengths. However, traditional frequent graph pattern mining approaches have the limitations that do not consider such problems. That is, the existing methods consider only one minimum support threshold regardless of the lengths of graph patterns extracted from their mining operations and do not use any of the patterns' weight factors; therefore, a large number of actually useless graph patterns may be generated. Small graph patterns with a few vertices and edges tend to be interesting when their weighted supports are relatively high, while large ones with many elements can be useful even if their weighted supports are relatively low. For this reason, we propose a weight-based frequent graph pattern mining algorithm considering length-decreasing support constraints. Comprehensive experimental results provided in this paper show that the proposed method guarantees more outstanding performance compared to a state-of-the-art graph mining algorithm in terms of pattern generation, runtime, and memory usage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.20-27
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• 2010

This paper describes a design of 5-stage pipelined de-blocking filter with power reduction scheme and proposes a efficient memory architecture and filter order for high performance H.264/AVC Decoder. Generally the de-blocking filter removes block boundary artifacts and enhances image quality. Nevertheless filter has a few disadvantage that it requires a number of memory access and iterated operations because of filter operation for 4 time to one edge. So this paper proposes a optimized filter ordering and efficient hardware architecture for the reduction of memory access and total filter cycles. In proposed filter parallel processing is available because of structured 5-stage pipeline consisted of memory read, threshold decider, pre-calculation, filter operation and write back. Also it can reduce power consumption because it uses a clock gating scheme which disable unnecessary clock switching. Besides total number of filtering cycle is decreased by new filter order. The proposed filter is designed with Verilog-HDL and functionally verified with the whole H.264/AVC decoder using the Modelsim 6.2g simulator. Input vectors are QCIF images generated by JM9.4 standard encoder software. As a result of experiment, it shows that the filter can make about 20% total filter cycles reduction and it requires small transposition buffer size.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.60-68
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• 2012

Current wireless sensor networks are considered to support more complex operations ranging from military to health care which require energy-efficient and timely transmission of large amounts of data. In this paper, we propose an adaptive temporal suppression algorithm which exploits a temporal correlation among sensor readings. The proposed scheme can significantly reduce the number of transmitted sensor readings by sensor node, and consequently decrease the energy consumption and delay. Instead of transmitting all sensor readings from sensor node to sink node, the proposed scheme is to selectively transmit some elements of sensor readings using the adaptive temporal suppression, and the sink node is able to reconstruct the original data without deteriorating data quality by linear interpolation. In our proposed scheme, sensing data stream at sensor node is divided into many small sensing windows and the transmission ratio in each window is decided by the window complexity. It is defined as the number of a fluctuation point which has greater absolute gradient than threshold value. We have been able to achieve up about 90% communication reduction while maintaining a minimal distortion ratio 6.5% in 3 samples among 4 ones.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.481-491
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• 2015

Since the crack in the surface of the concrete acts as the main reason influencing the life span of the structure, regular inspections and maintenance are required. The sealing required for maintenance of the concrete surface is a method of repairing the crack in the surface in the beginning, and is effective in preventing additional cracks and expansion that occurs with time. However, sealing on large sized structures such as tall buildings or bottom parts of bridges are difficult to ensure safety of the workers due to inadequate working environments. Due to this reason, the importance of the need for sealing automation for the maintenance of large sized concrete structures is emerging. This study proposes two control methods to apply robot systems to the sealing of cracks on the bottom parts of concrete bridges. First is the method of automatically tracking the trajectory of cracks. The robot gets the trajectory of the cracks using video information obtained from cameras. Comparing the previous several points and new point, the next point can be estimated. Thus, the trajectory of the crack can be tracked automatically. The other method is sealing by maintaining steady force to the contacting surface. The concrete surface exposed to an external environment for a long time gets an irregular roughness. If robots are able to carry out sealing while maintaining a steady contact force on these rough surfaces, complete equal sealing can be maintained. In order to maintain this equal force, a force control method using impedance is proposed. This paper introduces two developed control methods to apply to sealing robots, and conducts a Lab Test and Field Test after applying to a robot. Based on the test results, opinions on the possibilities of field application of the robot applied with the control methods are presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.303-310
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• 2018

One of most shocking headlines is a serious chain collision accident (CCA). The development of CCA has a temporal and spatial locality, and the information of the CCA is time-critical. Due to these characteristics of CCA, traffic accident information should be rapidly propagated to drivers in order to reduce chain collisions, right after the first accident occurs. Inter-vehicle communication (IVC) based on ad-hoc communication is one of promising alternatives for locally urgent information propagation. Despite this potential of IVC, research for the effects of IVC on the reduction of CCA has not been reported so far. Therefore, this study develops the parallel platform of microscopic vehicle and IVC communication simulators and then analyses the effects of IVC on the reduction of the second collision related to a series of vehicles. To demonstrate the potential of the IVC-based propagation of urgent traffic accident information for the reduction of CCA, the reduction of approaching-vehicle speed, the propagation speed of accident information, and then the reduction of CCA were analysed, respectively, according to scenarios of combination of market rates and traffic volumes. The analysis results showed that CCA can be effectively reduced to 40~60% and 80~82% at the penetration rates of 10% and 50%, respectively.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.11a
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• pp.29-29
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• 2002

공구강 등 산업용 재료로 널리 사용되는 카바이드 계 재료는 입자 크기 및 분포에 따라 기계적 성질이 변화하므로, 이를 제어하고 조절하는 기술에 관하여 많은 연구가 진행되어 왔다. 본 연구에서는 TiCN-WC-Co 복합초경계 에서 소결 공정 및 조성변화에 따른 입자 모양을 관찰하고 이에 따른 업자 성장 거동을 고찰하였다. 일반적으로 입자 조대화 양상과 고상 입자의 모양과는 밀접한 관계가 있다. 각진 입자의 경우에 는 계면이 원자적으로 singular 하여 원자의 홉착이 어렵기 때문에 임계값 이상의 성장 구동력을 받 는 몇몇 입자만 성장하는 비정상 입자 성장이 일어날 수 있다. 반면에 계면이 rough한 퉁큰 엽자의 경우에는 원자 홉착에 필요한 구동력이 존재하지 않아 성장 구동력을 받는 모든 입자들이 성장하기 때문에 정상 입자 성장을 하게 된다. 이와 같이 입자 모양에 따른 입자 성장 거동은 전체 미세구조를 결정하게 되며, 이에 따른 물리 화학적 물성을 변화시킨다. 이러한 입자 성장 원리를 적용하 면 복합초경계 (TiCN-WC-Co)에서도 입자성장이 억제되고 치밀한 소결체를 제조할 수 있을 것이다. 본 실험에서는 평균입도가 각각 0.1, 1.33, 2$\mu\textrm{m}$인 TiCN, WC, Co 분말을 사용하여 $((I00_{-x)}TiCN+_xWC)-30Co$ (wt%) 조성에서 TiCN/WC 비를 변화시키면서 업자 모양과 입자성장 거동을 관찰하였다. 청량된 분말은 WC 초경 볼로 밀렁하고, 건조한 후, 100 mesh 체로 조립화 하였다. 이 분말을 100 MPa의 압력으로 냉간정수압성형 하고 $10^{-2}$ torr의 진공분위기의 graphite f furnace에서 carbon black으로 packing 하여 액상형성 온도 이상에서 소결하였다. 소결된 시편은 경면 연마하여 주사전자현미경으로 미세 조직을 관찰하였다. TiCN-30Co 조성 시편은 corner-round 모양의 입자 모양으로 소결 시간 증가에 따라 빠른 입자 성장을 나타내었다 .(7STiCN+2SWC)-30Co 조성 시변의 경우 일반적으로 보고된 바와 같이 core/shell 구조를 나타내었으며, core는 TiC-rich 상이었고, shell은 (Ti,W)(C,N) 복합 탄화물 상이었다. WC 함량이 중가함에 따라 입자의 corner-round 영역이 증가하였으며 (SOTiCN-SOWC)-30Co 조성 근처에서는 거의 둥근 형태의 입자 모양을 나타내었다. 또한 TiCN - 30Co 조성 시편에 비하여 WC가 첨가된 시펀들은 작은 평균입자크기를 나타내었다. 본 연구의 결과는 shell 영역 조성 변화는 계면에너지 이방성과 기지상 내의 펑형 입자 모양을 변화시키고 나아가 입자 성장 속도 에도 영향을 미친다는 것을 보여준다.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.232-240
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• 2018

This study was performed to investigate the effects of water temperature and salinity on the egg development and larval attachment of Ascidiella aspersa. The egg development and larval attachment were examined in 12 different water temperatures (6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26 and $28^{\circ}C$) and two salinity conditions(30 and 34 psu). The hatching and developmental rates of A. aspersa showed a tendency to increase with increasing water temperature regardless of salinity and to decrease after the optimal water temperature range. The optimal water temperatures for the hatching and development of egg of A. aspersa were in the range of $20-22^{\circ}C$. The low threshold water temperature was not different between 1.5 and $1.8^{\circ}C$ at 30 and 34 psu, respectively. The attachment rate showed the optimal water temperature range of $16-22^{\circ}C$ irrespective of the salinity and the attachment time increased continuously with increasing water temperature. Experimental results showed that optimum development and survival temperature of the egg and larvae of A. aspersa were in the range of $20-22^{\circ}C$ regardless of the salinity conditions. The results can be used to predict the distribution and occurrence of A. aspersa, and to prevent economic damages caused by its spread.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.502-511
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• 2002

컴퓨터의 기술적 발전은 사회 여러 분야에 막대한 영향을 끼쳤다. 그중 악보인식분야에도 커다란 영향을 주었다. 그러나, On-line 상에서 그린 악보를 실시간으로 정형화된 악보형태로 변환하는 처리에 대한 연구가 미흡하여 이에 대한 연구가 필요하다. 본 논문에서는 실시간으로 악보를 인식하고, 사용자의 편의를 도모하기 위해 DP(Dynamic Programming) 매칭 법을 이용한 On-Line 악보인식에 관한 방법을 제안하였다. 본 연구에서는 실시간으로 입력되는 악상기호를 인식하기 위해, 가장 유효한 정보인 악상 기호내의 방향, x, y 좌표를 이용하여 벡터형태로 추출한 후 음표와 비음 표(쉼표, 기타기호)의 두개의 그룹으로 나누어진 표준패턴과의 DP매칭을 통해 인식한다. 먼저 tablet을 통해 실시간으로 악상 기호를 입력할 때 생기는 x, y좌표를 이용하여, 펜의 움직임에 대한 16방향 부호화를 수행한다. 음표와 비 음표를 구분하기 위한 시간을 줄이고자 16방향 부호화를 적용하지 않고 사사분면부호화를 적용한다. 음표를 약식으로 그릴 경우 음표 머리에 해당하는 부분의 좌표는 삼사분면에 분포하고, 폐곡선의 음표일 경우에는 좌표가 사사분면에 고르게 나타난다. 폐곡선을 제외한 음표의 머리는 폐곡선과 같은 조건이면서 입력받은 y좌표 값들 중에서 최소 값과 최대 값을 구한 다음 2로 나눈 값을 지나는 y좌표의 개수가 임의의 임계값 이상이면 음표로 판단한다. 위 조건을 만족하지 않을 경우 비 음표로 취급한다. 음표와 비 음표를 결정한 다음, 입력패턴과 표준패턴과의 DP매칭을 통하여 벌점을 구한다. 그리고 경로탐색을 통해 벌점에 대한 각각의 합계를 구해 최소 값을 악상기호로 인식하였다. 실험결과, 표준패턴을 음표와 비음표의 두개의 그룹으로 나누어 인식함으로써 DP 매칭의 처리 속도를 개선시켰고, 국소적인 변형이 있는 패턴과 특징의 수가 다른 패턴의 경우에도 좋은 인식률을 얻었다.리되고 이원화된 코드체계와 데이터 형태의 이질화를 통일하는 방법으로 데이터웨어하우스 시스템을 제시하였다. 결국 병원에서 데이터웨어하우스 시스템의 구축은 임상, 연구, 교육의 유기적 순환관계를 정립하여 지식의 순환적 고리인 수집, 공유, 확산, 재창출을 지속적 유지할 수 있는 인프라를 구축해 준다. 반면 상이한 정보들간의 충돌과 이에 따른 해석의 오류로 잘못된 의사결정을 위한 정보를 제공할 수 있고 기초정보의 접근 및 추출의 유용성에 의해서 정보유출에 대한 문제가 한계점으로 나타났다.로세스 개선을 위해서 무엇을 정말로 필요로 하는지를 밝힘으로써, 한국 소프트웨어 산업의 현실적인 특수성을 고려한 소프트웨어 프로세스 평가와 개선 모델의 개발을 위한 기초적인 자료를 제공할 것으로 예상된다. 또한, 본 연구 결과는, 우리나라 소프트웨어 조직들이 실제로 무엇을 필요로 하는지를 밝힘으로써, 우리나라의 소프트웨어 산업을 육성하기 위한 실효성 있는 정책 입안을 위한 기초 자료를 제공할 것으로 예상된다.를 검증하려고 한다. 협력체계 확립, ${\circled}3$ 전문인력 확보 및 인력구성 조정, 그리고 ${\circled}4$ 방문보건사업의 강화 등이다., 대사(代謝)와 관계(關係)있음을 시사(示唆)해 주고 있다.ble nutrient (TDN) was highest in booting stage (59.7%); however no significant difference was found among other stages. The concentrations of Ca and P were not different among mature stages. According to these results, the yellow ripe period is appropriate to harvest the whole crop rice for forage considering

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1027-1034
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• 2005

IEEE802.15.4a, which is started to realize the PHY layer including high precision ranging/positioning and low data rate communication functions, requires a simple and low power consumable transceiver architecture. To satisfy this requirements, the simple noncoherent on-off keying (OOK) UWB transceiver with the parallel energy window banks (PEWB) giving high precision signal processing interface is proposed. The flexibility of the proposed system in multipath fading channel environments is acquired with the pulse and bit repetition method. To analyze the bit error rate (BER) performance of this proposed system, a noise model in receiver is derived with commonly used random variable distribution, chi-square. BER of $10^{-5}$ under the line-of-sight (LOS) residential channel is achieved with the integration time of 32 ns and signal to noise ratio (SNR) of 15.3 dB. For the non-line-of-sight (NLOS) outdoor channel, the integration time of 72 ns and SNR of 16.2 dB are needed. The integrated energy to total received energy (IRR) for the best BER performance is about $86\%$.