• 식물조직배양학회지
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• 제27권4호
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• pp.345-352
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• 2000

Food production is a major role of agriculture. It has been projected that the world population continues to increase by the middle of the 21st century, and the population growth results in raising a serious problem of food shortage. Thus we have to increase food as possible. A considerable amount of crops have been abandoned due to short-life after postharvest. Ethylene is a factor responsible for the postharvest loss in crops, especially horticultural crops. If we can reduce ethylene production or sensitivity by genetic engineering, we can develop, so called,“long-life crop”conferring long postharvest lives. During last two decades, intensive research for molecular dissection of ethylene biosynthesis has been carried out, and the researchers have succeeded in engineering ethylene productivity in some crops. On the other hand, after the successful isolation of Arabidopsis ethylene receptor gene ETR1, the homolog genes have been isolated in various plant species. Currently the characterization of these genes and alteration of ethylene sensitivity using the genes are in progress. This review summarizes current progress in the analysis of these genes, and discusses genetic engineering of ethylene sensitivity using these genes.

• 대한치과의사협회지
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• 제56권1호
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• pp.8-16
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• 2018

Purpose: The aim of in vitro study was to compare the diagnostic accuracy to detect non-cavitated enamel caries on smooth surface by using four kinds of the QLF devices. Materials and Methods: A total of 52 human permanent premolars and molars were used. Fluorescence images were captured by the QLF devices (Inspektor Pro, QLF-D, Qraycam, and Qraypen). Fluorescence loss of the QLF was calculated. The severity of lesions was categorized into the following 3 scores using polarized light microscopy: normal (S), enamel demineralization to outer half of enamel (D1), and inner half of the enamel up to the dentin-enamel junction (D2). The Kruskal-Wallis test was used to compare the fluorescence loss among the QLF devices. Spearman rank correlation coefficient between histological scores and fluorescence loss of the devices was calculated. The sensitivity, specificity, and area under the receiver operating curve (AUROC) were calculated to compare their diagnostic accuracies. Results: The correlation coefficients between histological scores and the fluorescence loss of the devices showed 0.77 to 0.81 (P < 0.001). All histological scores, the fluorescence loss among the devices showed no statistical difference. Among the devices, sensitivity, specificity, and AUC values of the fluorescence loss showed 0.84 to 0.94, 0.76 to 0.90, and 0.90 to 0.92, respectively. Conclusions: All QLF devices had no difference with excellent diagnostic accuracies to detect non-cavitated enamel caries on smooth surface.

• 한국실천공학교육학회논문지
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• 제2권1호
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• pp.42-46
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• 2010

공학교육의 한 방법으로 광섬유 센서 제작 시 반드시 필요한 광섬유 접속기 사용은 보다 감도가 높은 센서를 제작하는데 필수적이다. 본 연구에서는 광섬유 접속기를 이용한 광 접속 손실을 실제 실험을 통하여 평가하고 실습에 사용된 방법이 교육적 효과를 거두기 위한 여러 가지 요소들을 분석하였다. 많은 실습을 통하여 광접속기 손실은 실습지들의 학습태도와 실험 환경의 변화에 많이 의존됨을 확인하였다.

• Journal of KIEE
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• 제11권1호
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• pp.51-54
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• 2001

In this paper, a MW-Mvar investment technique focused on minimizing the system loss is presented. An optimization technique, in which the system loss is defined as the objective function and the power flow equations as the constraints, is introduced to obtain the Lagrangian multipliers λP and λQ. The Lagrangian multipliers imply the variation of the system loss with respect to incremental bus power and are used as MW-Mvar investment indices for minimizing the system loss. ΔP MW and ΔQ Mvar are invested, step by step, by the priority of λP and λQ index given for each bus. Derivation of the index uses the information from normal power flow calculation.

• 수산해양기술연구
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• 제36권2호
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• pp.132-138
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• 2000

The effect of fluid flow on corrosion and erosion-corrosion of metal is a well-recognized phenomenon in pipelines and machinery equipment, and so on. Not only are fluid hydrodynamics important, but also the corrosiveness of the process or production stream affects the corrosion system. Recent research demonstrates that it is possible to erosion-corrosion(E/C) phenomena in terms of hydrodynamics, electrochemical corrosion kinetics and film growth/removal phenomena. Stress corrosion cracking behavior under cavitation erosion-corrosion of mild steel(SS41) was investigated of base metal and weldment under loaded stress. Main result obtained are as follows : 1) The cavitation erosion sensitivity of base metal affected weight loss is more susceptive than heat affected zone, 2) The corrosion sensitivity affected weight loss of welding heat cycle is less susceptive on stress corrosion under cavitation erosion-corrosion than stress corrosion.

• 대한전기학회논문지:전력기술부문A
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• 제49권1호
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• pp.6-12
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• 2000

This paper presents various processes of dynamic voltage collapse which is initiated by various power system disturbances, and the impacts of dynamic voltage controllers. According to the analysis results, the composition of induction motors with short time constants affects the voltage collapse strongly. Also, it is proved that the addition of fast acting reactive compensation devices, such as SVC, at high reactive loss sensitivity($$\delta$$Q$$_luss/\delta$$P$$_L$$) buses could be one of the best countermeasure to escape the voltage collapse.

• 음성과학
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• 제11권3호
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• pp.175-180
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• 2004

In case of the hearing impairment with tinnitus and increased sound sensitivity, it is known that the patients tend to appeal the psychologically oriented social handicap rather than communication disability. The audiologist who is responsible for such patients in aural rehabilitation should pay special attention to the counseling techniques including tinnitus retain therapy (TRT), ear protector, noise generator, or specific acoustic training based on close cooperation and rapport. And then the audiologist should try to lessen their reaction to the tinnitus by using a hearing aid. This therapies tries to focus not a. total approach but a treatment to lessen the severity of tinnitus. This paper as a case report that a unilateral sharply slopped sensorineural hearing impaired person with tinnitus and increased sound sensitivity by using four channel digital signal processing (DSP) hearing aid with programming increment at low level (PILL).

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.337-341
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• 2010

A high sensitivity fiber optic temperature sensor based on a side-polished fiber (SPF) coupled to a tapered multimode overlay waveguide (MMOW) is proposed and studied. Both tapered and non-tapered MMOW were considered to study the effect of tapering of MMOW on the characteristics of the device and to investigate the criticality of the uniformity of the multimode overlay waveguide over the SPF. Present study shows that tapering of the MMOW can be used to tune the desired wavelength range without any loss in the sensitivity. Sensitivity up to 9 nm/$^{\circ}C$ within the temperature range of 25 to $100^{\circ}C$ can be achieved with the proposed sensor, almost 6 times higher compared even to state-of-the-art high-sensitivity grating-based fiber optic temperature sensors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.196-198
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• 2003

The low load power factor causes various problems such as the increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is derived and its effects in supplying the reactive power and enhancing the load power factor are analyzed in a small-scale power system. The load power factor sensitivity of the generation cost is applied for determining the locations and capacities of reactive power compensation devices. It is shown that the generation cost can be reduced and the system power factor can be enhanced effectively using the load power factor sensitivity.

• KIEE International Transactions on Power Engineering
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• 제5A권3호
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• pp.252-259
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• 2005

Various problems such as increase of power loss and voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and restructuring of electric power companies makes the comprehensive management of reactive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of generation cost is derived and it is used for effectively determining the locations of reactive power compensation devices and for enhancing the load power factor appropriately. In addition, voltage variation penalty cost is introduced and integrated costs including voltage variation penalty cost are used for determining the value of load power factor from the point of view of economic investment and voltage regulation. It is shown through application to a large-scale power system that the load power factor can be enhanced effectively using the load power factor sensitivity and the integrated cost.