• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.141-151
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• 2002

The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

• Research in Plant Disease
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• v.16 no.1
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• pp.10-20
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• 2010

Root-knot nematodes cause billions of dollars in crop losses annually have a broad range of host over 2,000 species of plants. These nematodes are known as obligate, sedentary endo-parasites in a plant host to feed upon to complete their life cycle. To prevent the plant parasitic nematode, methyl bromide was widely applied as a soil fumigant. Other strategies to prevent or control nematodes involve RNAi-mediated suppression, R gene transformation, natural products or chemical treatments, the expression of peptide or proteins in susceptible plants, and others. Over the last decade, the entry in GenBank for Meloidogyne reveals 73,340 ESTs and recently two complete Meloidogyne spp. genomes sequences have simultaneously been presented by two groups. Recent works have demonstrated the effect of RNAi suppression to nematode target genes. These results will provide novel members of genes as a foundation for studies focused on understanding the function of M. incognita nematode genes as well as for the development of novel target genes for parasite control. Thus the successful development of biotechnology-derived plants with nematode resistance will result in large yield benefits for producers as well as environmental benefits and will accelerate the research related to pathogensresistant crops.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.7
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• pp.464-472
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• 2001

Asymmetric n-MOSFET＇s for improving packing density have been fabricated with 0.35 ${\mu}{\textrm}{m}$ CMOS process. Electrical characteristics of asymmetric n-MOSFET show a lower saturation drain current and a higher linear resistance compared to those of symmetric devices. Substrate current of asymmetric MOSFET is lower than that of symmetric devices. Asymmetric n-MOSFET＇s have been modeled using a parasitic resistance associated with abnormally structured drain or source and a conventional n-MOSFET model. MEDICI simulation has been done for accuracy of this modeling. Simulated values of reverse as we11 as forward saturation drain current show good agreement with measured values for asymmetric device.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.581-582
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• 2006

In this paper, we investigate three different types of multi-fingered layout nMOSFET devices with varying $W_f$(unit finger width) and $N_f$(number of finger). Using layout modification, we improve $f_T$(current gain cutoff frequency) value of 15GHz without scaling down, and moreover, we decrease $NF_{min}$(minimum noise figure) by 0.23dB at 5GHz. The RF noise can be reduced by increasing $f_T$, choosing proper finger width, and reducing the gate resistance. For the same total gate width using multi-fingered layout, the increase of finger width shows high $f_T$ due to the reduced parasitic capacitance. However, this does not result in low $NF_{min}$ since the gate resistance generating high thermal noise becomes larger under wider finger width. We can obtain good RF characteristics for MOSFETs by using a layout optimization technique.

• The Plant Pathology Journal
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• v.38 no.4
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• pp.366-371
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• 2022

The white soybean cyst nematode Heterodera sojae, isolated from the roots of soybean in Korea, is widespread in most provinces of the country and has the potential to be as harmful to soybean as H. glycines. Determining the virulence phenotypes of H. sojae is essential to devising management strategies that use resistant cultivars. Consequently, virulence phenotypes of 15 H. sojae populations from Korea were determined on seven soybean lines and one susceptible check variety. Two different HS types were found to be present in Korea; the more common HS type 2.5.7, comprising 73.3% of the H. sojae populations and the less common HS type 0, constituting only 26.7% of the tested populations. Considering the high frequency of H. sojae adaptation to soybean indicator lines, the PI 88788 group may not be a possible source of resistance while PI 548402, PI 90763, PI 437654, and PI 89772 can be used as resistance sources for soybean breeding programs aimed at developing H. sojae-resistant soybean cultivars in Korea.

• ETRI Journal
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• v.27 no.5
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• pp.628-634
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• 2005

From AC analysis results utilizing a 2-dimensional device simulator, we extracted an AC-equivalent circuit of a grounded-gate NMOS (ggNMOS) electrostatic discharge (ESD) protection device. The extracted equivalent circuit is utilized to analyze the effects of the parasitics in a ggNMOS protection device on the characteristics of a low noise amplifier (LNA). We have shown that the effects of the parasitics can appear exaggerated for an impedance matching aspect and that the noise contribution of the parasitic resistances cannot be counted if the ggNMOS protection device is modeled by a single capacitor, as in prior publications. We have confirmed that the major changes in the characteristics of an LNA when connecting an NMOS protection device at the input are reduction of the power gain and degradation of the noise performance. We have also shown that the performance degradation worsens as the substrate resistance is reduced, which could not be detected if a single capacitor model is used.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.11
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• pp.97-106
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• 1992

In integrated circuits, protection circuits are required to protect the internal nodes from the harmful ESD(Electrostatic discharge). This paper discusses the characteristics of the circuit components in ESD protection circuitry in order to analyze the ESD phenomina, and the design methodalogy of ESD protection circuits, using test pattern with a variation of the number of diode and transistor. The test devices are fabricated using a 0.8$\mu$m CMOS process. SPICE simulation was also carried out to relate output node voltage and measured ESD voltage. With increasing number of diodes and transistors in protection circuit, the ESD voltage also increases. The ESD voltage of the bi-directional circuit for both input and output was 100-300[V], which in higher than that of only output(uni-directional) circuit. In addition, the ESD protection circuit with the diode under the pad region was useful for the reduction of chip size and parasitic resistance. In this case, ESD voltage was improved to a value about 400[V].

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1386-1392
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• 2009

An analysis is presented for super-high-speed optical demodulation by an avalanche photodiode(APD) with electric mixing. A normalized gain is defined to evaluate the performance of the optical mixing detection. Unlike previous work, we include the effect of the nonlinear variation of the APD capacitance with bias voltage as well as the effect of parasitic and amplifier input capacitance. As a results, the normalized gain is dependent on the signal frequency and the frequency difference between the signal and the local oscillator frequency. However, the current through the equivalent resistance of the APD is almost independent of signal frequency. The mixing output is mainly attributed to the nonlinearity of the multiplication factor. We show also that there is an optimal local oscillator voltage at which the normalized gain is maximized for a given avalanche photodiode.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.344-345
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• 2011

스마트 그리드 산업으로 인하여 신재생에너지의 활용이 중시되고 있는 시점에서 신재생에너지원을 더욱 효율적이고 안정적으로 사용하기 위해서는 에너지 저장장치의 필요성이 부각되고 있다. 신재생 에너지원을 사용하기 위한 부스트 컨버터와 충방전기를 설계시 일반적으로 시뮬레이션을 통해 설계를 하게 된다. 이때, 인덕터와 커패시터를 이상적인 소자라고 생각하고 시뮬레이션 하거나, 실제 하드웨어와 같이 인덕터와 커패시터에 기생하는 저항을 포함시켜 시뮬레이션을 하게 된다. 본 논문에서는 신재생 에너지원을 계통에 사용할 수 있도록 저전압 상태에서의 신재생 에너지원 출력전압을 승압시켜 인버터를 사용할 수 있도록 만들어 주는 부스트 컨버터의 인덕터를 이상적인 경우와 기생저항이 포함된 경우 각각의 조건하에서 충방전기와 연결하였을 경우 충방전기의 설계에 어떠한 영향을 주는지를 알기 위해 부스트 컨버터의 출력 임피던스 수식을 통해 분석한 MATLAB과 PSIM을 통해 시뮬레이션을 하여 증명하였다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.6
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• pp.54-61
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• 1996

In this paper, the conventional ZVS-QRC buck dc-dc converter is analyzed using simulation and the problem in confirmed through it. According to varying the load resistance lower, it is provided that the stress of the device is increased. The reason is seen that the voltage is increased by parasitic capacitance of freewheeling diode. Novel ZVS-converter is proposed to improve the problems.