• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1485-1488
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• 2003

This paper proposes a wireless EMG-based human-computer interface (HCI) for persons with disabilities. For the HCI, four interaction commands are defined by combining three elevation motions of shoulders such as left, right and both elevations. The motions are recognized by comparing EMG signals on the Levator scapulae muscles with double thresholds. A real-time EMG processing hardware is implemented for acquiring EMG signals and recognizing the motions. To achieve real-time processing, filters such as high- and low-pass filter and band-pass and -rejection filter, and a full rectifier and a mean absolute value circuit are embedded on a board with a high speed microprocessor. The recognized results are transferred to a wireless client system such as a mobile robot via a Bluetooth module. From experimental results using the implemented real-time EMG processing hardware, the proposed wireless EMG-based HCI is feasible for the disabled.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.310-317
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• 2011

Perceptibility and acceptability are the most often used threshold units in the field of color science. The former refers to a just perceptible difference and the latter evokes a tolerable color difference. Such thresholds can be very significant to color quality control processes in the printing industry and should be defined in quality measure units. Optical density (OD) and color difference models are usually utilized as color quality measures and have been provided in a considerable number of commercial measuring devices such as spectrophotometers. However, their merits and traits are far less understood in the literature. The present study intends to evaluate performance of those color quality measures including the OD and widely known color difference models, e.g. ${\Delta}E{^*}_{ab}$, ${\Delta}E_{CMC(l:c)}$ and ${\Delta}E{^*}_{00}$. A set of psychophysical assessments were carried out in order to accumulate the perceptibility and acceptability thresholds data, and their central trend was compared with the color quality measure estimates.

• International Journal of Contents
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• 제8권2호
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• pp.19-22
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• 2012

New and handoff calls control mechanisms are the key point to wireless cellular networks. In this paper, we present an adaptive algorithm for dynamic channel allocation scheme with guard channels and also with handoff calls waiting queue ensuring that handoff calls take priority over new calls. Our goal is to find better tradeoff between handoffs and new calls blocking probabilities in order to achieve more efficient channel utilization. Simpy is a Python based discrete event simulation system. We use Simpy to build our simulation models to get analytical data.

• 한국응용곤충학회지
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• 제31권3호
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• pp.205-240
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• 1992

In reality, it is a green revolution of the entire agricultural matrix in Korea that integrated pest control plays an important role in the possible breakthrough in rice self-sufficiency. In paddy agroecosystem as man-modified environment, rice is newly established every year by transplantation under diverse water regimes which affect a microclimate. Standing water benefits rice by regulating the microclimate, but it favors the multiplication of certain pets through the amelioration of the microclimate. Further, the introduction of high yielding varieties with the changing of cultural practices results in changing occurrence pattern of certain pests. In general, japonica type varieties lack genes resistant to most of the important pests and insect-borne virus diseases, whereas indica type possesses more genes conferring varietal resistance. Thus, this differences among indica type, form the background of different approaches to pest management. The changes in rice cultivation such as double cropping, growing high-yielding varieties requiring heavy fertilization, earlier transplanting, intensvie-spacing transplanting, and intensive pesticide use as a consequence of the adoption of improves rice production technology, have intensified the pest problems rather than reduced them. The cultivation of resistant varieties are highly effective to the pest, their long term stability is threathened because of the development of new biotypes which can detroy these varieties. So far, three biotypes of N. lugens are reported in Korea. Since each resistant variety is expected to maintain several years the sequential release of another new variety with a different gene at intervals is practised as a gene rotation program. Another approach, breeding multilines that have more than two genes for resistance in a variety are successfully demonstrated. The average annual rice losses during the last 15 years of 1977-’91 are 9.3% due to insect pests without chemical control undertaken, wehreas there is a average 2.4% despite farmers’insecticide application at the same period. In other words, the average annual losses are prvented by 6.9% when chemical control is properly employed. However, the continuous use of a same group of insecticides is followed by the development of pest resistance. Resistant development of C. suppressalis, L. striatellus and N. cincticeps is observed to organophosphorous insecticides by the mid-1960s, and to carbamates by the early 1970s in various parts of the country. Thus, it is apparent that a scheduled chemical control for rice production systems becomes uneconomical and that a reduction in energy input without impairing the rice yield, is necessarily improved through the implementation of integrated pest management systems. Nationwide pest forecasting system conducted by the government organization is a unique network of investigation for purpose of making pest control timely in terms of economic thresholds. A wise plant protection is expected to establish pest management systems in appropriate integration of resistant varieties, biological agents, cultural practices and other measures in harmony with minimizing use of chemical applications as a last weapon relying on economic thresholds.

• The Korean Journal of Pain
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• 제14권1호
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• pp.7-11
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• 2001

Background: Although several mechanisms of causalgia, which results from a partial injury to the peripheral nerve trunk, have been proposed, whether or not antidromic impulses from the injured neurons contribute to the development of the mechanical hyperalgesia has not been studied. The purpose of this experiment is was to investigate the role of antidromic impulses to the peripheral sensory receptor site on the development of mechanical hyperalgesia in a rat model of peripheral neuropathy. Methods: Rats were prepared with tight ligation of by tightly ligating the left fifth and sixth lumbar spinal nerves. The effect of bupivacaine pretreatment on the development of mechanical hyperalgesia was evaluated by injecting 0.5% bupivacaine (0.3 ml) into the plantar surface of the left hind paw before the skin incision was made. For the control group, normal saline (0.3 ml) was injected instead of bupivacaine. To measure the mechanical hyperalgesia, paw withdrawal thresholds were measured using a series of von Frey hairs. Mechanical hyperalgesia was measured a the day before, and 1, 2, 3, 4, 7, and 14 days after the surgery. Results: The control group showed decreased withdrawal thresholds from the day after the surgery (the values were $14.0{\pm}0.5$, $8.9{\pm}1.3$, $8.4{\pm}1.6$, $6.9{\pm}1.2$, $8.8{\pm}1.5$, $10.5{\pm}1.3$, and $8.6{\pm}1.3$ g; at -1, 1, 2, 3, 4, 7, and 14 days after the surgery, respectively). However, withdrawal thresholds of the bupivacaine-pretreated group showed increased withdrawal thresholds for three days after the surgery ($14.5{\pm}0.3$, $12.6{\pm}1.4$, $12.7{\pm}1.1$, $10.5{\pm}1.3$ g; at 1, 1, 2, 3 days after the surgery). Conclusions: Our result suggests that antidromic impulses to the peripheral sensory receptors are at least partly responsible for the initial development of mechanical hyperalgesia in a rat model of peripheral neuropathy.

• 한국통신학회논문지
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• 제28권3A호
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• pp.129-139
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• 2003

호 수락제어 기법은 CDMA시스템에서 통화중인 호들의 통화품질을 보장하고 시스템의 용량을 증가시킬 수 있는 중요한 기법이다. 본 논문에서는 다중 종류의 문턱치를 사용한 호 수락제어 기법(MCAC : multiple thresholds CAC)을 제시하고 컴퓨터 시뮬레이션을 통하여 그 성능을 분석하였다. 이 기법에서는 두 가지 종류의 문턱치를 이용하여 새로운 호의 호 신청 수락여부를 결정한다. 첫 번째 문턱치는 통화중인 사용자의 수이고 두 번째 문턱치는 기지국에서 측정되는 신호-대-간섭비이다. 통화중인 사용자의 수가 시스템에서 새로운 사용자를 받아들일 수 있는 충분한 여유용량이 있다고 판단하는 문턱치보다 적으면 신호-대-간섭비를 측정하지 않고 직접 새로운 호의 호 신청을 수락하고 통화중인 사용자의 수가 시스템에서 통화품질을 만족할 수 없다고 판단하는 문턱치보다 많으면 새로운 호의 호 신청을 거절하도록 한다. 통화중인 사용자의 수가 두 문턱치사이에 위치하면 측정된 신호-대-간섭비에 근거하여 호 수락여부를 결정한다. 제안된 알고리즘의 성능평가를 위하여 시스템의 통화품질 저하확률(outage probability)과 호 차단확률(call blocking probability) 및 전 처리확률(pre-processing probability)을 이용하며 제안된 알고리즘의 성능을 기존에 제시된 사용자수에 기반한 알고리즘과 신호-대-간섭비에 기반한 알고리즘과 비교하도록 한다. 실험결과는 제안된 알고리즘이 기존의 신호-대-간섭비에 기반한 알고리즘의 우수한 성능을 유지하면서 호 수락 처리속도를 높일 수 있음을 보여준다.

• Journal of Mechanical Science and Technology
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• 제19권4호
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• pp.985-992
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• 2005

Vehicle Stability Control (VSC) system prevents vehicle from spinning or drifting out mainly by braking intervention. Although a control threshold of conventional VSC is designed by vehicle characteristics and centered on average drivers, it can be a redundancy to expert drivers in critical driving conditions. In this study, a manual adaptation of VSC is investigated by changing the control threshold. A control threshold can be determined by phase plane analysis of side slip angle and angular velocity which is established with various vehicle speeds and steering angles. Since vehicle side slip angle is impossible to be obtained by commercially available sensors, a side slip angle is designed and evaluated with test results. By using the estimated value, phase plane analysis is applied to determine control threshold. To evaluate an effect of control threshold, we applied a 23-DOF vehicle nonlinear model with a vehicle planar motion model based sliding controller. Controller gains are tuned as the control threshold changed. A VSC with various control thresholds makes VSC more flexible with respect to individual driver characteristics.

• 한국응용곤충학회지
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• 제48권1호
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• pp.81-86
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• 2009

배추에서 파밤나방의 경제적피해수준과 요방제수준을 설정하기 위해 시험한 결과, 파밤나방의 접종시기별 피해엽율은 정식 5일째(1차 접종)에 20주에 80마리 접종시 8일만에 63.2%의 피해엽율로 가장 높았으며, 정식 20일째에 접종(2차 접종)한 경우 10일째에 80마리 접종구에서 40.7%, 14일째에 43.1%로 증가하다 이후 감소하였다. 배추 파밤나방의 유충밀도와 수량감소율과의 관계는 정식 5일은 Y = -10.62x + 867.9 ($R^2\;=\;0.643$), 정식 20일에는 Y=-6.432x + 1074 ($R^2\;=\;0.720$)이며, 경제적 피해수준은 5.4마리, 9.0마리이며, 5% 수준에서 요방제 밀도는 각각 4.3마리, 7.2마리였다. 배추생육 시기 및 파밤나방 접종밀도에 따른 피해율과 수량감소율의 관계는 정의 상관을 나타내어 배추의 수량에는 파밤나방의 초기 피해가 크게 작용한 것으로 판단되었다.

• 한국응용곤충학회지
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• 제45권3호
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• pp.317-325
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• 2006

2004년 잎들깨 주요 해충을 조사하였던 바, 잎들깨 시설하우스내에서 발생하는 주요 해충들은 들깨진딧물(Aphis egomae), 들깨잎말이명나방(Pyrausta panopealis), 점박이응애(Tetranychus urticae), 차먼지응애(Polyphagotarsonemus latus), 차응애(Tetranychus kanzawai) 등이었다. 그 중에서 들깨진딧물은 방제를 하지 않았을 경우 100%에 가까운 피해를 주는 중요한 해충으로 밝혀졌다. 본 연구는 발생초기 100주당 1마리에서 80마리 수준으로 들깨진딧물 성충을 인위적으로 접종하였을 경우 잎들깨 포장에서의 경제적 피해 수준과 요방제수준을 밝히고자 수행 하였다. 100주당 $1{\sim}80$마리가 접종되었을 때 평균 피해주율은 6월 하순경 $2.4%{\sim}40.5%$였다. 시험기간 동안의 방제비용(C)를 시장가격(V)으로 나누었을 때 진딧물의 발생초기인 4월부터 6월 13일까지 경제적 손실을 일으키는 시점은 5.8%였으며 진딧물의 발생최성기인 6월 13일부터 6월 30일까지의 경우 9.3%였다. 들깨진딧물의 발생 초기에서의 경제적 피해수준은 주당 5.3마리였으며 발생최성기 때의 경제적 피해수준은 주당 0.6마리와 7.6% 피해주율 이었다. 경제적 피해수준의 80% 수준에서의 요방제 수준은 들깨진딧물의 발생최성기인 6월의 경우 주당 0.5마리와 피해주율 6.1%였다.

• 한국응용곤충학회지
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• 제46권3호
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• pp.431-435
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• 2007

대파에서 파밤나방의 접종시기와 접종량에 따른 피해엽율을 조사하고 수량과 관계를 조사한 결과는 다음과 같다. 파밤나방의 접종시기별 피해엽율은 정식 5일째(1차 접종)의 경우 20주에 40마리 접종과 5마리 접종에서 9월 7일에 각각 33.5%와 10.9%를 나타내었다. 정식 20일째에 접종(2차 접종)한 경우 9월 7일에 20.5%를 보였으나 1차 접종 보다는 낮았다. 파밤나방 무접종구의 수량은 3,495.2 kg/10a이었으며 1차 40마리 접종구의 수량은 1,774. 2kg/10a로 수량감소율은 49.2%였으며 2차 접종구의 수량 2,220.5 kg/10a로 수량 감소율은 36.5%였다. 파 파밤나방의 유충밀도와 수량감소율과의 상관관계식은 정식 5일은 Y = -43.474x + 3419.6 ($R^2\;=\;0.9698$), 정식 20일에는 Y = -32.977x + 3518.9 ($R^2\;=\;0.9928$)로 대파재배 시 파밤나방 유충의 요방제 수준은 정식 5일째의 경우 20주당 1.8마리이며, 정식 20일째의 경우 20주당 4.6마리였다. 파밤나방 접종밀도에 따른 피해율과 수량감소율의 관계는 정의 상관을 나타내어 피해가 클수록 수량 감소율도 크게 나타나 대파의 수량에는 파밤나방의 피해가 크게 작용하였다.