• The Journal of the Petrological Society of Korea
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• v.15 no.4 s.46
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• pp.180-193
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• 2006

The Gilan area in the central-northern part of Uiseong Block of Cretaceous Gyeongsang Basin is composed of Precambrian metamorphic rocks, Triassic Cheongsong granite, Early Cretaceous Hayans Group, and Late Cretaceous-Paleocene igneous rocks. In this area, the faults of various directions are developed: Oksan fault of $NS{\sim}NNW$ trend, Gilan fault of NW trend, Hwanghaksan fault of WNW trend, and Imbongsan fault of EW trend. Several fracture sets with various geometric indicators, which determine their relative timing (sequence and coexistence relationships) and shear sense, we well observed in the Cheongsong granite, the basement of Gyeongsang Basin. The aim of this study is to determine the development sequence of extension fractures and the movement sense of shear fractures in the Gitan area on the basis of detailed analysis of their geometric indicators (connection, termination, intersection patterns, and cross-cutting relations). This study suggests that the fracture system of the Gilan area was formed at least through seven different fracturing events, named as Pre-Dn to Dn +5 phases. The orientations of fracture sets show (W) NW, NNW, NNE, EW, NE in descending order of frequency. The orientation and frequency patterns are concordant with those of faults around and in the Gilan area on a geological map scale. The development sequence and movement sense of fracture sets are summarized as follows. (1) Pre-Dn phase: extension fracturing event of $NS{\sim}NNW$ and/or $WNW{\sim}ENE$ trend. The joint sets of $NS{\sim}NNW$ trend and of $WNW{\sim}ENE$ trend underwent the reactivation histories of sinistral ${\rightarrow}$dextral${\rightarrow}$sinistral shearing and of (dextral${\rightarrow}$) sinistral shearing with the change of stress field afterward, respectively. (2) Dn phase: that of NW trend. The joint set experienced the reactivations of sinistral${\rightarrow}$dextral shearing. (3) Dn + 1 phase: that of $NNE{\sim}NE$ trend. The joint set was reactivated as a sinistral shear fracture afterward. (4) Dn +2 phase: that of $ENE{\sim}EW$ trend. (5) Dn +3 phase: that of $WNW{\sim}NW$ trend. (6) Dn+4 phase: that of NNW trend. The joint set underwent a dextral shearing after this. (7) The last Dn +5 phase: that of NNE trend.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.295-307
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• 1988

In order to predict performance of the intake manifold, which is dependent on the length and diameter of a resonance pipe, the Fluid Dynamic Model for 4-cylinder diesel engine is developed using two step Lax-Wendroff method to solve the governing equations of air flow in the intake system. Boundary conditions at the intake valve, branch at the manifolds, and pipe end are also modeled. The results of the models are compared with the experimental results of a motored engine. The model is capable of predicting the real phenomena satisfactorily with reasonable computing time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.154-161
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• 2010

This paper considers the simultaneously firing model for the artillery operations. The objective of this paper is to find the optimal fire sequence minimizing the final completion time of the firing missions of multiple artillery units for multiple targets. In the problem analysis, we derive several solution properties to reduce the solution space. Moreover, two lower bounds of objective are derived and tested along with the derived properties within a branch-and-bound scheme. Two efficient heuristic algorithms are also developed. The overall performances of the proposed branch-and-bound and heuristic algorithms are evaluated through various numerical experiments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.22-22
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• 2021

큰졸방제비꽃(Viola kusanoana)의 엽록체 DNA 염기서열을 밝히고자 차세대염기서열분석법(NGS)을 이용하여 분석하였다. 재료는 경상북도 울릉군 나리분지에 자생하는 개체의 잎을 사용하였다. 염기서열 분석결과, 총 길이는 158,644 bp 였고, GC함량은 36.3%로 분석되었다. 구간별로는 LSC (Large single copy)지역이 86,999 bp (GC content: 33.9%)였고 SSC (Small single copy)지역은 17,439 bp (GC content: 29.9%)으로 분석되었으며 IR (Invertied repeats)지역은 27,103 bp (GC content: 42.2%)로 확인되었다. 유전자는 protein coding gene 77개, tRNA gene 30개, rRNA 4개 등 총 111개로 이는 선행 연구된 제비꽃속 8개 분류군과 유전자의 순서와 방향이 모두 일치하였다. 이를 통해 제비꽃속의 엽록체 게놈의 유전자는 상당히 보존되어 있음을 확인하였다.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.233-241
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• 2024

This study was conducted to investigate the geological distribution characteristics of fluorine in rocks, which can be a major resource of forest aggregates in Korea. Samples of forest aggregates were collected from 224 sites in 22 cities and counties for this study. The national background concentration was 344 mg/kg, which was significantly lower than the average fluorine concentration of crustal, which was 625 mg/kg, and slightly higher than the average fluorine concentration of world soil, which was 321 mg/kg. In terms of region and tectonic structure, fluorine concentrations were investigated to be highest in Gyeonggi-do(394 mg/kg) and Gyeonggi massif(396 mg/kg), respectively. The concentration distribution by the origin of the parent rock was in the order of metamorphic rock(362 mg/kg) > sedimentary rock(354 mg/kg) > igneous rock(328 mg/kg), and the concentration distribution by geologic ages was the highest in the Paleozoic at 394 mg/kg. The concentration distribution by rock types was in the order of diorite(515 mg/kg) > gneisses(377 mg/kg) > schists(344 mg/kg) > phyllite(306 mg/kg) > granites(305 mg/kg) > quartz porphyry(298 mg/kg). Consequently, it is speculated that gneisses and schists, Precambrian metamorphic rocks in the Gyeonggi massif that forms the crust of Gyeonggi-do, contain high fluorine concentrations.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.77-88
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• 2015

In this paper, we consider a two-agent single-machine scheduling problem with exponential job-dependent position-based learning effects. The objective is to minimize the total weighted completion time of one agent with the restriction that the makespan of the other agent cannot exceed an upper bound. First, we propose a branch-and-bound algorithm by developing some dominance /feasibility properties and a lower bound to find an optimal solution. Second, we design an efficient simulated annealing (SA) algorithm to search a near optimal solution by considering six different SAs to generate initial solutions. We show the performance superiority of the suggested SA using a numerical experiment. Specifically, we verify that there is no significant difference in the performance of %errors between different considered SAs using the paired t-test. Furthermore, we testify that random generation method is better than the others for agent A, whereas the initial solution method for agent B did not affect the performance of %errors.

• Economic and Environmental Geology
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• v.34 no.2
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• pp.175-192
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• 2001

We have collected hydrogeochemical data of shallow groundwaters in the Uljin area located at eastern coastal area of Korea. Geostatistical analysis (ANOVA test, cluster analysis, and factor analysis) of the collected data sets was pert'onned, in order to evaluate both the spatial and/or temporal variation of water quality data and the groundwater contamination, as weJl as the principal reactions occurring in the aquifer. Results of the ANOVA test show that regional water chemistry are not significantly changed spatially in eight watersheds. However, some ions such as $Ca^{2+}$, $HCO_{3}^{-}$ and $SO_{4}^{2-}$ show a meaningful watershed variation. Water chemistry variation according to sampling time (season) is not shown, except for $SO_{4}^{2-}$. The cluster analysis shows that significant water chemistry variation is eXplained by the distance from the coast. Factor analysis indicates that the water chemistry is changed according to various factors as follows: in the order of decreasing importance, water-rock interaction (mainly, carbonate dissolution), sea-salt spraying, and then contamination by fertilizers and agrochemicals.

• Animal Systematics, Evolution and Diversity
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• v.2 no.2
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• pp.67-78
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• 1986

한국해역에서 알려진 집게류는 12과 57종, 게류는 20과 183종이다. 집게류는 집게과 (Paguridae) (19종)와 넓적왼손집게 과 (Diogenidae) (12종) 의 종들이 많고 게류에서는 물맞이게 과 (Maidae) (33종) 의 종이 가장 asg고 다음이 바위게 과(Grapsidae) (29종), 부채게 과 (Xanthidae) (22종), 꽃게 과 (Portunidae) (16종) , 달랑게 과(Ocypodidae) (16종)의 순이다. 저자는 한국 해역을 동해, 대한해협, 제주도해역, 황해의 4구역으로 나누고, 집게류와 게류를 북방형, 온대형, 남방형의 3분지형으로 나누었다. 집게류의 경우 북방형 9종, 온대형 40종, 남방형 8종이고, 게류의 경우 북방형 7종, 온대형 87종, 남방형 89종이다. 집게류의 경우 동행 29종, 대한해협에 30종, 제주도해역에 30종, 황해에 21종이 게류의 경우 위의 순서대로 62종, 121 종, 104 종, 74종이 분포하며, 각 해역에서의 분포형도 고찰했다. 각 해역에만 분포하는 종의 수는 집게의 경우 동해에 8종, 대한해협에 3종, 제주도해역에 16종, 황해에 0종, 게류의 경우 위의 순서로 8종, 20종 40종, 12종이다. 집게류는 북방형종이, 게류는 남방형종이 비교적 많으며 동해에는 북방형종들이 제주도에는 남방형종들이 비교적 많다. 4구역 중 2 구역 (6조합) 사이의 유사계수(r=a/a+b+c)를 계산한 바 양 분류군 모두 대한 해협과 황해 사이의 유사성이 가장 크고 (집게류 ; 0.55, 게류 : 0.59), 제주도해역과 황해 사이의 유사성이 가장 적다. (집게류 ; 0.20, 게류 : 0.19). 분포상을 이해하기 위하여 각 해역의 환경조건도 알아보았는바, 분포의 양상과 해황과 잘 부합된다.

• Journal of the Korean earth science society
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• v.21 no.3
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• pp.230-249
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• 2000

Southeastern Korean Peninsula has undergone the polyphase deformations according to the changes of regional tectonic settings during the Cenozoic. Through analyses of more than 600 fault-slip data gathered in the study area, five tectonic events are revealed as the followings: (I) NW-SE transtension, (II) NW-SE transpression, (III) NE-SW pure or radial extension, (IV) NNE-SSW transpression, (V) NE or ENE-WSW transpression. Event I was induced by the pull-apart type extension of the East Sea during 24-16 Ma, which resulted in the NW-SE extension of the Tertiary Basins in SE Korea. Event II was resulted from the collision of SW Japan and Izu-Bonnin Arc (or Kuroshio Paleoland) on the Philippine Sea Plate at ${\sim}$ 15 Ma, which stopped the extension of the Tertiary Basins and originated the uplift of fault blocks in and around SE Korean Peninsula. It was continued until ${\sim}$ 10 Ma. Event III is interpreted as the post-tectonic event after the block-uplifts due to the event II, which indicates a temporal lull in activity of the Philippine Sea Plate since 10 Ma. Event IV was originated from the resumption in activity of the Philippine Sea Plate which was restarted to move toward north at ${\sim}$ 6 Ma. The event made the EW compressional structures behind SW Japan as well as in the Korea Straits, and thus the block-uplifts in SE Korea was resumed again. Lastly, event V was resulted from the gradual decrease in influence of the Philippine Sea Plate and the cooperative compression due to the subduction of the Pacific Sea Plate and the collision of the Indian Plate since 5-3.5 Ma, which generated the NS compressional structures in the offshore along the eastern coast of the Korean Peninsula and thrust up the fault-blocks toward west. This event is continuing so far, and thus is making the active faultings resulting in the present earthquakes of the Korean Peninsula.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.39-44
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• 1999

High-resolution images are drawn from existing seismic data which were originally obtained by Korea Ocean Research & Development Institute (KORDI) during 1994-1997 for deep seismic studies on the East Sea of Korea. These images are analyzed for mapping Quaternary faults and near-bottom gas pockets. First 12 channels are selected from shot gathers for reprocessing. The processing sequence adopted for high-resolution seismic images comprises data copy, trace editing, true amplitude recovery, common-midpoint sorting, initial muting, prestack deconvolution, bandpass filtering, stacking, highpass filtering, poststack deconvolution, f-x migration, and automatic gain control (AGC). Among these processing steps, predictive deconvolution, highpass filtering, and short window AGC are the most significant in enhancement of resolution. More than 200 Quaternanry faults are interpreted on the migrated sections in the shallow depths beneath the seafloor. Although numerous faults are found mostly at the western continental slope and boundaries of the Ulleung Basin, significant amount of the faults are also indicated within the basin. Many of these faults are believed to be formed with reactivation of basement, from geotectonic activities including volcanism, and often originated in Tertiary, indicating that the tectonic regime of the East Sea might be unstable. Existence of shallow gas pockets casts real hazardous warnings to deep-sea drillings and/or to underwater constructions such as inter-island cables and gas pipelines. On the other hand, discovery of these gas pockets heightens the interests in developing natural resources in the East Sea. Reprocessed seismic sections, however, show no typical seismic characteristics for gas hydrates such as bottom-simulating reflectors in the western continental slope and ocean floor.