• 대한인간공학회지
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• 제36권5호
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• pp.535-543
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• 2017

Objective: This study was designed to identify factors affecting pilots' +Gz tolerance recovery from +Gz induced exhaustion. Background: +Gz tolerance of pilots has been considered as a crucial factor to fly the modern high performance fighter aircrafts. However, the factors affecting pilots' G-tolerance recovery from +Gz induced exhaustion have not been examined in the acceleration research community. Method: A centrifuge profile consisting of a high +Gz run for pilot's exhaustion and a low +Gz run for pilot's recovery and another high +Gz runs for pilot's second exhaustion was designed. The subjects' +Gz tolerance recovery ratio was measured by ratio of second high +Gz run time to the first high +Gz run time. The subjects' +Gz tolerance recovery rate was measured by dividing the subjects' +Gz tolerance recovery ratio by the low +Gz run time. The subjects' G-tolerance recovery rate was analyzed with respect to the subjects' personal factors including subjects' anthropometric and physiologic characteristics, flight time, flying aircraft type and so on. Results: The subjects' previous three-month flight hours (r=-0.336, p=0.039), six-month flight hours (r=-0.403, p=0.012) and one-year flight hours (r=-0.329, p= 0.044) correlated with the subjects' G-tolerance recovery rate. Conclusion: The subjects' G-tolerance recovery rate is clearly related to the subjects' previous flight hours. However, the subjects' anthropometric and physiologic characteristics do not show any statistically significant correlation with the subjects' G-tolerance recovery rate. Application: This research provides a safety critical insight to aviation community by identifying the factors to affect the gravity-induced loss of consciousness (GLOC) of pilots.

• The Plant Pathology Journal
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• 제27권1호
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• pp.20-25
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• 2011

Gibberella zeae (anamorph: Fusarium graminearum), a homothallic (self-ferile) ascomycete with ubiquitous geographic distribution, causes serious diseases in several cereal crops. Ascospores (sexual spores) produced by this fungal pathogen have been suggested as the main source of primary inoculum in disease development. Here, we report the function of a gene designated GzRUM1, which is essential for ascospore formation in G. zeae. The deduced product of GzRUM1 showed significant similarities to the human retinoblastoma (tumor suppressor) binding protein 2 and a transcriptional repressor, Rum1 in the corn smut fungus (Ustilago maydis). The transcript of GzRUM1 was detected during the both vegetative and sexual stages, but was more highly accumulated during the latter stage. In addition, no GzRUM1 transcript was detected in a G. zeae strain lacking a mating-type gene (MAT1-2), a master regulator for sexual development in G. zeae. Targeted deletion of GzRUM1 caused no dramatic changes in several traits except ascospore formation. The ${\Delta}$GzRUM1 strain produced perithecia (sexual fruit bodies) but not asci nor ascospores within them. This specific defect leading to an arrest in ascospore development suggests that GzRUM1, as Rum1 in U. maydis, functions as a transcriptional regulator during sexual reproduction in G. zeae.

• 대한인간공학회지
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• 제15권1호
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• pp.69-78
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• 1996

Current fighter pilots, flying new generation aircrafts with high performance, are under severe stress during aerial combat maneuvering when they are exposed to high sustained +Gz(Head-to-foot) acceleration stress. Two major factor limiting performance during high sustaied +Gz acceleration stress are loss of vision-greyout or blackout, and loss of consciousness (LOC). These symptoms are believed to occur as a result of insuff- icient blood flow to the retina and the brain. This study was conducted to evaluate the effects of high sustained +Gz stress under different seat back angle. The results. obtained by the biodvanmic computer simulations using the ATB(articulated total body) model, are represented with respect to three variables, such as HIC(head injury criterion) value, average G, and maximum G. The results demonstrate that the seat back angle(over $30^{\circ}C$) had a significant effect to decrease +Gz stress on the head segment and had no significant effect on HIC.

• 한국주조공학회지
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• 제36권2호
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• pp.60-66
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• 2016

In this study, comparison of corrosion properties of the Mg-1.5Ge-1Zn (GZ21) alloy and Mg-9Al-1Zn (AZ91) alloy were investigated. The studied alloys were fabricated by permanent mold casting method. And the potentiodynamic test, hydrogen evolution test, immersion test and A.C Impedance test were carried out in a 3.5% NaCl solution with pH7.2 at room temperature to measure the corrosion properties. The microstructure of GZ21 alloy was composed of ${\alpha}-Mg$ and $Mg_2Ge$ phases and AZ91 alloy was composed of ${\alpha}-Mg$ and $Mg_{17}Al_{12}$ phases. From the test results, the corrosion property was improved by adding Ge. It seemed that the corrosion mechanism was changed from galvanic corrosion (AZ91) to filiform corrosion (GZ21).

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2005년도 한국식물병리학회 임시총회 및 춘계학술발표회
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• pp.84-85
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• 2005

• The Plant Pathology Journal
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• 제27권4호
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• pp.301-309
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• 2011

The filamentous fungus Fusarium graminearum is an important cereal pathogen. Although quantitative realtime PCR (qRT-PCR) is commonly used to analyze the expression of important fungal genes, no detailed validation of reference genes for the normalization of qRT-PCR data has been performed in this fungus. Here, we evaluated 15 candidate genes as references, including those previously described as housekeeping genes and those selected from the whole transcriptome sequencing data. By a combination of three statistical algorithms (BestKeeper, geNorm, and NormFinder), the variation in the expression of these genes was assessed under different culture conditions that favored mycelial growth, sexual development, and trichothecene mycotoxin production. When favoring mycelial growth, GzFLO and GzUBH expression were most stable in complete medium. Both EF1A and GzRPS16 expression were relatively stable under all conditions on carrot agar, including mycelial growth and the subsequent perithecial induction stage. These two genes were also most stable during trichothecene production. For the combined data set, GzUBH and EF1A were selected as the most stable. Thus, these genes are suitable reference genes for accurate normalization of qRT-PCR data for gene expression analyses of F. graminearum and other related fungi.

• 해양환경안전학회지
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• 제1권1호
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• pp.27-38
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• 1995

In this paper, a program for the calculation of GZ curve for a ship in waves is developed and GZ curves for a ferry in the still water and in waves are calculated. And the added mass, damping, restoring forces and wave exciting forces are calculated by using the strip theory given by Salvesen, Tuck, Faltinsen. Capsizing simulations are perfoned in consideration if the nonlinear restoring forces of the ship in waves by using the Runge-Kutta 4-th method.

• 디지털융복합연구
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• 제16권5호
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• pp.399-406
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• 2018

인공지능을 이용한 침입탐지 연구는 KDDCup99 데이터 세트를 사용하여 많은 연구가 이루어졌다. 이전 연구에서 SMO(SVM)알고리즘의 성능이 우수하다고 알려져 있다. 하지만 훈련에 사용되지 않은 새로운 침입유형의 침입탐지연구는 미비하다. 본 논문에서는 웨카(weka)의 SMO와 KDDCup99 훈련 데이터 세트인 kddcup.data.gz의 인스턴스를 이용하여 모델을 생성하였다. corrected.gz 파일의 인스턴스 중 기존 침입(292,300개)과 새로운 침입(18,729개)을 테스트하였다. 일반적으로 훈련에 사용되지 않은 침입 라벨은 테스트 되지 않기 때문에 새로운 침입라벨을 normal.로 변경하여 테스트하였다. 새로운 침입 18,729개의 인스턴스 중 1,827개는 침입으로 분류하였다. 새로운 침입으로 분류한 1,827개의 인스턴스는 buffer_overflow. 3개, neptune. 392개, portsweep. 164개, ipsweep. 9개, back. 511개, imap. 1개, satan. 개, 645 개, nmap. 102개로 분류되었다.

• 한국수산과학회지
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• 제9권4호
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• pp.287-292
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• 1976

1) A선형은 배수량이 2,400톤인 경우 KG의 값이 3.40m, 3.70m때 안정상태를 나타내었으며 배수량이 1,600톤 1,900톤 2,200톤일 경우는 KG의 값이 3.40m때 어느정도 안정범위에 있음이 판정되었다. 2) B선형은 배수량이 2,400톤일 경우 KG의 값이 3.40m때 만이 어느정도 안정범위에 있으나 배수량이 1,30 $0\~2,200$톤일 경우 KG값이 $3.40\~4.60m$때는 모두 위험범위에 있음이 판정되었다. 3. A선형은 GM의 값이 2.14m이고 $GZ_max$ 1.395m때 안정범위에 있고 B선형은 GM의 값이 2.14m이고 $GZ_max$ 1,890m때 어느 정도 안정범위에 있음이 판정되었다. 끝으로 본연구를 하는데 지도하여 주신 부산공대 김진안 교수님과 자료를 제공해 주신 대양조선주식회사 정부장씨께 감사드리며, 계산과정에서 협조해준 양주호군에게 사의를 표한다.

• 대한조선학회논문집
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• 제52권3호
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• pp.187-197
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• 2015

This study aims the development of a semi-analytic method for the parametric roll of large containerships advancing in longitudinal waves. A 1.5 Degree-of-Freedom(DOF) model is proposed to account the change of transverse stability induced by wave elevations and vertical motions (heave and pitch). By approximating the nonlinearity of restoring moment at large heel angles, the magnitude of roll amplitude is predicted as well as susceptibility check for parametric roll occurrence. In order to increase the accuracy of the prediction, the relationship between righting arm(GZ) and metacentric height(GM) is examined in the presence of incident waves, and then a new formula is proposed. Based on the linear approximation of the mean and first harmonic component of GM, the equation of parametric roll in irregular wave excitations is introduced, and the computational results of the proposed model are validated by comparing those of weakly nonlinear simulation based on an impulse-response-function method combined with strip theory. The present semi-analytic doesn’ t require heavy computational effort, so that it is very efficient particularly when numerous sea conditions for the analysis of parametric roll should be considered.