• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.214-214
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• 2019

가뭄이 '심함' 단계 이상 도달 시에는 매주 수문분석을 수행하여 가뭄전망을 수행하여야 한다. 이를 위해서는 기상청의 강수량과 기온 등의 기상예측 자료가 필요하다. 현재 기상청에서는 3개월 기상전망으로 월단위 강수량과 평균기온을 매월 제공하고 있다. 1개월 전망에서 4주의 강수량합과 평균기온을 제공하고 있다. 하지만, 향후 4주간을 전망하는 1개월 전망에서는 1주단위의 강수량과 평균기온이 아닌, 4주간의 강수량합과 평균기온을 1주일 단위로 업데이트해 WINS에 제공하고 있다. 1주단위의 강수량과 평균기온을 취득하기 어려워, 평년 일단위 강수량과 평균기온 자료를 사용하여 4주간의 자료를 1주 단위로 분할하는 방법을 사용하였다. 주간단위 수문자료의 처리를 위해 국제표준기구(ISO)에서 제시하는 기준(ISO 8601)에 따랐다. ISO 8601은 월요일부터 일요일까지를 1주로 정의하며 현재 사용하고 있는 날짜체계와 1대1로 대응되도록 하였다. 예를 들면 1981년 2월 22일은 '1981-W07-7' 또는 '1981W077'로 표시한다. 표시된 형식은 1981년 7번째 주 일요일을 뜻한다. 이 기준에 따라 수문자료를 정리할 수 있도록 프로그램을 개발하였다. 주간 단위 잠재증발산량 계산은 월잠재증발산량 프로그램을 1주단위로 계산할 수 있도록 수정 및 보완하여 개발하였다. 수정 및 보완한 부분은 외기복사(外氣輻射)량 계산부분이다. 외기복사량은 지구가 태양을 1년 주기로 공전하므로 특정 위도에서 특정날짜에 따라 복사량이 달라지므로 주간단위의 월요일부터 일요일에 해당하는 날짜의 외기복사량을 각각 계산하고 이를 평균하여 주간단위 대푯값으로 사용하도록 하였다. 계산된 주간단위 외기복사량과 최고 최저기온을 입력하여 Hargreaves식에 의해 잠재증발산량을 계산한다. 융적설을 포함한 주단위 강우-유출 모형의 매개변수를 추정하기 위해 전국 24개 지점의 수문자료를 사용하였다. abcd 모형과 융적설모듈의 초기값 포함 11개 매개변수를 SCE-UA 전역최적화 알고리즘으로 추정하였다. 추정된 유역의 매개변수는 토양배수, 토양심도, 수문지질, 유역특성인자를 사용한 군집분석 결과에 의해 113개 중권역에 할당하였다. 개발된 주간단위 강우-유출 모형은 비교적 단기 가뭄전망을 위해 사용된다. 계산된 유량은 자연유량이며, 전국 취수장 수량, 하수처리장 방류수, 회귀수를 반영하여 지점별 유량을 계산하여 가뭄전망에 사용되고 있다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.1
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• pp.50-69
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• 2001

Three kinds of high-speed signaling methods for synchronous DRAM (SDRAM) bus interface channels (PC-133, Direct-Rambus, and SSTL-2) were analyzed in terms of the timing budget and the physical transmission characteristics. To analyze the SDRAM bus interface channels, loss mechanisms and the effective characteristic impedance method were reviewed and the ABCD matrix method was proposed as an analytic and yet accurate method. SPICE simulations were done to get the AC responses and the eye patterns of the three SDRAM bus interface channels for performance comparisons. Recent progress and future trend for SDRAM bus interface standards were reviewed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.50-60
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• 2018

In this paper, we developed a broadband multi-layered radome applicable for high-power applications. In this regard, we presented the wave propagation characteristics of the broadband multi-layered radome with the ABCD matrix and obtained the optimal thickness and the material constant for each layer by an optimization algorithm called "particle swarm optimization," implemented by a commercial numerical modeling tool. Further, we redesigned it in view of mechanical properties to reflect environmental conditions such as wind, snow, and ice. The power transmission property was reanalyzed based on the recalculated data of each layer's thickness to consider the limitations of the fabrication of a large structure. Under the condition of a peak electric field strength that is 10 dB above the critical electric field strength in air breakdown, we analyzed the air breakdown by radio frequency(RF) in the designed radome using the commercial full-wave electromagnetic tool. The radome was manufactured and tested by continuous wave(CW) RF small signal and large signal in an anechoic chamber. The test results showed good agreement with those attained by simulation.

• Journal of Microbiology
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• v.44 no.1
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• pp.121-125
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• 2006

Mycothiol is a low molecular weight thiol compound produced by a number of actinomycetes, and has been suggested to serve both anti-oxidative and detoxifying roles. To investigate the metabolism and the role of mycothiol in Streptomyces coelicolor, the biosynthetic genes (mshA, B, C, and D) were predicted based on sequence homology with the mycobacterial genes and confirmed experimentally. Disruption of the mshA, C, and D genes by PCR targeting mutagenesis resulted in no synthesis of mycothiol, whereas the mshB mutation reduced its level to about $10\%$ of the wild type. The results indicate that the mshA, C, and D genes encode non-redundant biosynthetic enzymes, whereas the enzymatic activity of MshB (acetylase) is shared by at least one other gene product, most likely the mca gene product (amidase).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.1
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• pp.76-83
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• 2000

A 2-pole tunable bandpass filter was design and fabricated using ceramic coaxial resonators and varactor diodes for UHF band. By inspection of frequency characteristics of the T-and $\pi$-type inverter equivalent circuits, we can design a two-pole tunable BPF with only two varactors. The measured data of the filter show 800 MHz-900 MHz tunable center frequency range, 4.5 dB insertion loss, 0.5 dB passband ripple and at least 15 dB return loss, which agree well with the simulated results.

• Geotechnical Engineering
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• v.8 no.1
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• pp.81-102
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• 1992

Landslides on hillside slopes with shallow soil cover over a sloping bedrock are frequently caused by increases in porewater pressures following of heavy rainfall and it is one of the most important factors of assessing the risk of landslide to predict the groundwater level fluctuations in hillslopes. This paper presents the comparative study of three unsaturated flow models developed by Sloan et al., Reddi, L.N., and Thomas, H.A., Jr., respectively, which are used to predict the increase of groundwater levels in hillside slopes. The parametric study for each of models is also presented. The Kinematic Storage Model(KSM) developed by Sloan et at. is utilized to predict the saturated groundwater flow. They are applied to the two sites in Korea so as to examine the possibility of use in the groundwater flow model. The results show that two unsaturated models developed by Sloan et al. and Reddi, L. N. are largely affected by the uncertain parameters like saturated permeability and saturated water content : the abed model has the potential of use in unsaturated flow model with the optimal estimates of model parameters utilizing available optimization techniques. And it is also found that the KSM must be modified to account for the time delay effect in the saturated zone. The results of this paper are able to be utilized in developing the predictive model of groan dwater level fluctuations in a hillslope.

• Journal of the Korean Child Neurology Society
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• v.24 no.3
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• pp.71-83
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• 2016

X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ATP binding cassette subfamily D member 1 (ABCD1), a gene that encodes peroxisomal membrane located on ABC half-transporter named adrenoleukodystrophy protein (ALDP). X-ALD is characterized by a highly variable clinical spectrum, including progressive cerebral type, adrenomyeloneuropathy, and addison-only phenotype. No genotype/phenotype correlation has been established. Thus, unidentified modifier genes and other co-factors are speculated to modulate the phenotypic variation and disease severity. Recent advanced sequencing methods and reprogramming technologies not only offer an affordable and applicable approach to investigate the pathophysiological mechanisms of adrenoleukodystrophy, but also provide means to develop therapy. A causal therapy of X-ALD is lacking. Lorenzo's oil therapy is recommended for asymptomatic boys, but the longest study found that the oil was not beneficial at all to symptomatic X-ALD patients. Hematopoietic stem cell therapy has a relevant chance of success when performed during this early stage of cerebral type X-ALD. Recently, it has been insisted that lentiviral-mediated gene therapy of hematopoietic stem cells can provide clinical benefits in X-ALD. This review describes current knowledge on the clinical presentation, pathogenesis, diagnosis and management of X- ALD.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.9-18
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• 2003

Two configurations of Film Bulk Acoustic Wave Resonators with acoustic quater-wave bragg reflector layers are theoretically analyzed using equivalent circuits and the difference of their characteristics are discussed. We compare the characteristics of λ/2 mode to those of ideal FBAR with top and bottom electrode contacting air and the characteristics of λ/4 mode to those of ideal FBAR with top electrode contacting air and bottom electrode clamped. We assume that the piezoelectric film is ZnO, the electrode is A1 and the substrate is Si, ABCD parameters are extracted and input impedance is calculated by converting the equivalent circuit from Mason equivalent circuits to the simplified equivalent circuits that ABCD parameters are extracted possible, From the variation of resonance frequency due to the change of thickness of reflector layers and the variation of electrical Q due to the change of mechanical Q of reflector layers, it is confirmed that the reflector layer just under the bottom electrode have the greatest effect on the varation of resonance frequency and electrical Q. It is shown that the number of reflector layers required for the saturation of electrical Q decreases with the increase of the impedance ratio of reflector layers and electrical Q of λ/2 mode is larger than that of λ/4 mode, Electromechanical coupling factor is independent of the number of layers, The impedance ratio of reflector layers becomes larger as the electromechanical coupling factor becomes larger, The electromechanical coupling factor of the two mode are smaller than those of ideal FBARs because of the trapping of acoustic energy in the reflector layers, The insertion loss of the ladder filter decreases with the increase of the number of reflector layers but the bandwidth is not affected much by the number of reflector layers, As the impedance ratio of reflector layers becomes larger the insertion loss becomes smaller and the bandwidth becomes wider, In our analysis of the two mode, characteristics of λ/2 mode appear to be slightly more favorable than that of λ/4 mode

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1040-1043
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• 2008

Klebsiella oxytoca CCUG 15788 is resistant to $Ni^{2+}$ at a concentration of 10 mM and grows in an inducible manner when exposed to lower concentrations of $Ni^{2+}$. The complete genomic sequence of a 4.2-kb HindIII-digested fragment of this strain was determined from genomic DNA. It was shown to contain four nickel resistance genes (nirA, nirB, nirC, and nirD) encoding transporter and transmembrane proteins for nickel resistance. When the plasmid pKOHI4, encoding nirABCD, was transformed into Escherichia coli JM109, the cells were able to grow in Tris-buffered mineral medium containing 3 mM nickel. TnphoA'-1 insertion mutants in the four nickel genes nirA, nirB, nirC, and nirD showed nickel sensitivity. The nir genes were heterogeneously expressed in E. coli, suggesting functional roles of these genes in nickel resistance.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.197-214
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• 2021

In this paper, we have studied dynamics of fractional order mathematical model of malaria transmission for two groups of human population say semi-immune and non-immune along with growing stages of mosquito vector. The present fractional order mathematical model is the extension of integer order mathematical model proposed by Ousmane Koutou et al. For this study, Atangana-Baleanu fractional order derivative in Caputo sense has been implemented. In the view of memory effect of fractional derivative, this model has been found more realistic than integer order model of malaria and helps to understand dynamical behaviour of malaria epidemic in depth. We have analysed the proposed model for two precisely defined set of parameters and initial value conditions. The uniqueness and existence of present model has been proved by Lipschitz conditions and fixed point theorem. Generalised Euler method is used to analyse numerical results. It is observed that this model is more dynamic as we have considered all classes of human population and mosquito vector to analyse the dynamics of malaria.