• 한국작물학회지
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• 제44권2호
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• pp.143-148
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• 1999

Soil moisture condition is an important limiting factor in growth and yield in rice culture. The purpose of this study was to compare the influence on the growth, yield and Quality of rice subjected to soil moisture stress (SMS) at different growth stages. Ajaponica rice cultivar, Dongjinbyeo, was cultured under flooded conditions in a plastic container filled with silty loam soil. The container was subjected to SMS until the initial wilting point (IWP) coincided with about 10% in soil moisture content and about-200 kPa in soil matric potential, and was then irrigated again, at 6 and 5 of main growth stage in 1996 and 1997, respectively. At maturity, the plant height, tiller number, leaf area and top dry weight were decreased more in SMS treatments at the early stage than the late stage. The averaged yield index of SMS to control in both years was lowest at meiosis (62.5%), which primarily resulted from lower percent ripened grain and 1,000 grain weight, and second＇ reduced the spikelet number per panicle and panicle number per hill, and followed at tillering stage (68.5%) which resulted from the lower production in tiller number and top dry matter during and after SMS treatment. The percent-age of read rice in SMS plants varied with the treatment stage as order of lower at meiosis (44.0%), heading (53.9%), panicle initiation (70.1%), tillering (72.1%), ripening (75.8%) and 5 days after transplanting (DAT) (79.0%). Protein content in brown rice was slightly larger in SMS at late growth stage than the control, while the contents of fat and ash differed very little between SMS and control. Contents of Mg and K and Mg/K in brown rice with SMS were lower at some treatment stages such as at ripening or panicle initiation.

• Molecules and Cells
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• 제41권10호
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• pp.923-932
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• 2018

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized. However, the regulation and physiological roles of ACC oxidases (ACOs) that catalyze the final step of ethylene biosynthesis are largely unknown in Arabidopsis. Here, we show that Arabidopsis ACO1 exhibits a tissue-specific expression pattern that is regulated by multiple signals, and plays roles in the lateral root development in Arabidopsis. Histochemical analysis of the ACO1 promoter indicated that ACO1 expression was largely modulated by light and plant hormones in a tissue-specific manner. We demonstrated that point mutations in two E-box motifs on the ACO1 promoter reduce the light-regulated expression patterns of ACO1. The aco1-1 mutant showed reduced ethylene production in root tips compared to wild-type. In addition, aco1-1 displayed altered lateral root formation. Our results suggest that Arabidopsis ACO1 integrates various signals into the ethylene biosynthesis that is required for ACO1's intrinsic roles in root physiology.

• 한국작물학회지
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• 제52권4호
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• pp.458-468
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• 2007

To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.

• 한국통신학회논문지
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• 제23권6호
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• pp.1602-1609
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• 1998

본 논문은 CDMA 방식의 PCS 전화기용 고주파 전위회로에 관한 것으로 전력증폭기와 듀플렉서를 결합하여 하나의 모듈로 구성하였다. 기존의 듀플렉서를 구성하고 있는 유전체 여파기들이 서로 분리되어 전력증폭기내에서 재배치되며 특히 송신용 대역저지여파기가 전력증폭기의 구동증폭기 이후에 위치된다. 결합모듈은 크기가 1.5CC에 불과하여 전화기 소형화에 크게 기여할 것으로 기대된다. 출력 24dBm에서 IS-95에 준하는 CDMA 선형특성을 만족하였으며 PCS 송수신 주파수대역에서 필요한 감쇠특성을 나타내어 듀플렉서로서 역할도 수행하였다. 결합모듈의 출력단자가 곧바로 안테나에 연결되므로 결합전보다 출력이 줄어들게 되어 이에 상응하는 동작전류가 줄어들었으며, CDMA 전화기가 실제 환경에서 동작시 출력크기의 대부분이 선형영역에 있는 점을 감안하여 전력증폭기의 동작점을 B급으로 제한하여 전류소모를 줄였다. 이 결과 약 95mA 의 드레인 전류를 절약할 수 있었다.

• 전기학회논문지
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• 제65권5호
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• pp.730-737
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• 2016

Electric utilities may face new threats with increase in electric vehicles (EVs) in the personal automobile market. The peak demand will increase which may stress the distribution network equipment. The focus of this paper is on an adaptive control of smart household appliances by using an intelligent load management system (ILMS). The main objectives are to accomplish consumer needs and prevent overloading of power grid. The stress from the network is released by limiting the peak demand of a house when it exceeds a certain point. In the proposed strategy, for each smart appliance, the customers will set its order/rank according to their own preferences and then system will control the household loads intelligently for consumer reliability. The load order can be changed at any time by the customer. The difference between the set and actual value for each load's specific parameter will help the utility to estimate the acceptance of this intelligent load management system by the customers.

• 정보처리학회논문지C
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• 제9C권5호
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• pp.733-742
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• 2002

이동 컴퓨팅 환경에서 사용자의 이동 특성은 실시간 멀티미디어 서비스를 제공하기 위해서 요구되는 QoS에 심각한 영향을 미친다. 기존의 유선환경에서 실시간 서비스를 제공하기 위해서 제안된 RSVP 프로토콜을 이동 사용자의 네트워크 접속점이 수시로 변화하는 이동 컴퓨팅 환경에 적용하기에는 부적합하다. 사용자의 이동이 QoS에 미치는 영향을 최소화하기 위해서 사용자가 이동할 것으로 예상되는 영역에 대한 자원을 미리 예약하는 프로토콜이 MRSVP(Mobile RSVP)이다. 본 논문은 기존의 MRSVP를 확장하여 RSVP Tunnel 및 Mobile IP의 지역 등록(Regional Registration) 프로토콜이 결합된 동적 이중 앵커노드(DDAN : Dynamic Dual Anchor Node) 구조를 제안한다. 이는 기존의 MRSVP 프로토콜에서 미리 예약되는 자원을 지역적으로 제한함으로써 자원예약을 최소화시키는 반면에, 기존의 MRSVP와 유사한 수준의 QoS 보장을 목적으로 한다.

• Toxicological Research
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• 제33권4호
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• pp.291-297
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• 2017

This study was performed to investigate the dose-response relationship between average daily cadmium dose (ADCD) from rice and the occurrence of urinary cadmium (U-Cd) in individuals eating that rice. This was a retrospective cohort designed to compare populations from two areas with different levels of cadmium contamination. Five-hundred and sixty-seven participants aged 18 years or older were interviewed to estimate their rice intake, and were assessed for U-Cd. The sources of consumed rice were sampled for cadmium measurement, from which the ADCD was estimated. Binary logistic regression was used to examine the association between ADCD and U-Cd (cut-off point at $2{\mu}g/g$ creatinine), and a correlation between them was established. The lowest estimate was $ADCD=0.5{\mu}g/kg\;bw/day$ [odds ratio (OR) = 1.71; with a 95% confidence interval (CI) 1.02-2.87]. For comparison, the relationship in the contaminated area is expressed by $ADCD=0.7{\mu}g/kg\;bw/day$, OR = 1.84; [95 % CI, 1.06-3.19], while no relationship was found in the non-contaminated area, meaning that the highest level at which this relationship does not exist is $ADCD=0.6{\mu}g/kg\;bw/day$ [95% CI, 0.99-2.95]. Rice, as a main staple food, is the most likely source of dietary cadmium. Abstaining from or limiting rice consumption, therefore, will increase the likelihood of maintaining U-Cd within the normal range. As the recommended maximum ADCD is not to exceed $0.6{\mu}g/kg\;bw/day$, the consumption of rice grown in cadmium-contaminated areas should not be more than 246.8 g/day. However, the exclusion of many edible plants grown in the contaminated area from the analysis might result in an estimated ADCD that does not reflect the true level of cadmium exposure among local people.

• 응용통계연구
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• 제34권6호
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• pp.863-874
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• 2021

FLSA는 총변동벌점을 이용해 구간별상수인 평균 구조를 구현하는 벌점모형으로 다중변화점 탐색을 위해 활용되고 있다. 한편, FLSA는 변화점 탐색에 있어서 점근적 일치성이 만족되지 않으므로 잡음의 크기가 0에 가깝게 수렴하는 경우에도 다수의 거짓 변화점이 식별될 수 있다는 단점이 있다. 이 연구에서는 이러한 FLSA의 문제점을 해결하기 위한 사후추론 방법으로 순열검정 방법을 제안한다. 단일변화점 모형과 관련된 순열검정 방법은 Antoch와 Hušková (2001)에 의해 제안된 바 있다. 이 연구에서는 Antoch와 Hušková (2001)의 검정절차를 확장하여 다중변화점 식별에 사용되는 FLSA와 결합함으로써 다중변화점 모형에 적용할 수 있는 순열검정절차를 제안한다. 모의실험 결과, 제안된 방법은 z-검정과 CUSUM 통계량의 극한분포에 기반을 둔 검정방법에 비해 전반적으로 우수하였으며 거짓 변화점의 식별에 유용함을 확인할 수 있었다.

• 한국지구과학회지
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• 제40권4호
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• pp.353-381
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• 2019

The general world model for homogeneous and isotropic universe has been proposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a (4+1)-dimensional space-time, and assume that the universe is spatially a 3-dimensional hypersurface embedded in the 4-dimensional space. The simultaneity for the entire universe has been specified by the global time coordinate. We define the line element as the separation between two neighboring events on the expanding universe that are distinct in space and time, as viewed in the world reference frame. The information that determines the kinematics of the geometry of the universe such as size and expansion rate has been included in the new metric. The Einstein's field equations with the new metric imply that closed, flat, and open universes are filled with positive, zero, and negative energy, respectively. The curvature of the universe is determined by the sign of mean energy density. We have demonstrated that the flat universe is empty and stationary, equivalent to the Minkowski space-time, and that the universe with positive energy density is always spatially closed and finite. In the closed universe, the proper time of a comoving observer does not elapse uniformly as judged in the world reference frame, in which both cosmic expansion and time-varying light speeds cannot exceed the limiting speed of the special relativity. We have also reconstructed cosmic evolution histories of the closed world models that are consistent with recent astronomical observations, and derived useful formulas such as energy-momentum relation of particles, redshift, total energy in the universe, cosmic distance and time scales, and so forth. The notable feature of the spatially closed universe is that the universe started from a non-singular point in the sense that physical quantities have finite values at the initial time as judged in the world reference frame. It has also been shown that the inflation with positive acceleration at the earliest epoch is improbable.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.257-257
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• 2022

Late blight, caused by the hemibiotrophic oomycete pathogen Phytophthora infestans, has been the most important disease limiting potato production worldwide. P. infestans undergo major population shifts in agricultural systems via the successive emergence and migration of asexual lineages. The phenotypic and genotypic bases of these selective sweeps are largely unknown but management strategies need to adapt to reflect the changing pathogen population. Here, we used molecular markers to divide the 86 South Korea isolates into six clonal lineages: KR_1_A1, KR_2_A2, SIB-1, US-11, SIB-1 like, and KR-2 like. We documented the emergence of a new lineage, termed SIB-1 like, and KR-2 like, and their rapid replacement of other lineages to exceed 35% of the pathogen population across South Korea. Genome analyses of the Korean P. infestans populations revealed extensive genetic polymorphism, particularly in effector genes. Importantly, SIB-1 like isolates carry an intact Avr8 effector gene that triggers resistance in potato carrying the corresponding R immune receptor gene R8 cloned from Solarium demissum. These findings point toward a strategy for deploying genetic resistance to mitigate the impact of the SIB-1 like lineage and illustrate how pathogen population monitoring, combined with genome analysis, informs the management of devastating disease epidemics. Further study is being done on pathogenicity of the SIB-1 like isolates on cultivated potatoes and changes in expression patterns of disease effector genes within the SIB-1 like isolates