• Journal of Korea Water Resources Association
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• v.53 no.5
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• pp.347-356
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• 2020

The main objective of the study is to propose the most efficient SWAT model calibration method using SWAT-CUP with less computing time and high performance. In order to achieve the goal, Case1-3 (250, 500, and 1,000 simulation runs) and Case4 (1,000 simulation runs in the first iteration and then 500 simulation runs for the following iterations) were defined to compare the results. When evaluating the values of the objective function, Case2 and Case3 reached the same value after the fourth iteration, and Case1 reached the closed value of Case2-3 after the eighth iteration. However, the final estimates of the parameters had different ranges in Cases1-3, and only the results of Case3 and Case4 converged similarly. Thus, it can be considered that the parameter calibration results are highly affected by the initial number of simulation runs. On the other hand, SWAT simulation results did not show the significant difference after the first iteration, unlike the parameter ranges. From the analysis results, we can conclude that the most suitable and effective method was to repeat one or two times of iterations with a sufficient number of simulation runs, as in Case4.

• Research in Plant Disease
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• v.22 no.1
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• pp.9-17
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• 2016

Nationwide survey for angular leaf spot (ALS) of strawberry caused by Xanthomonas fragariae, a quarantine disease in Korea, was performed in November 2012. In the survey, ALS was observed in eighty eight farmers' fields of Sukok, Jinju and Okjong, Hadong in Gyeongnam Province, and one field in Namwon of Jeollabuk Province. The infected field of Namwon closed immediately after the disease diagnosed ALS. In detailed survey of Sukok and Okjong areas during February 2012 to January 2015, ALS occurrence decreased from 45% farmer's fields on December 2012 to 5% on January 2015, and from 38% on November 2013 to 5% on January 2015, respectively. Phenotypic characteristics of the Korean strains were similar to those of the type strain of X. fragariae. A multilocus sequence analysis of Korean strains of X. fragariae was conducted using four genes; dnaK, fyuA, gyrB, and rpoD. All the Korean strains had the same sequences of the four genes. The concatenated sequences of the Korean strains shared 100% with that of the type strain of X. fragariae. All strawberry cultivars tested were susceptible to the strains of X. fragariae two weeks after inoculation. The inoculated sites were necrosis and expanded, which were rated 4 based on evaluation of inoculation site.

• The Journal of the Petrological Society of Korea
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• v.15 no.2 s.44
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• pp.60-71
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• 2006

The Seokmodo consists mainly of biotite granite and granodiorite. The biotite granite is divided into the south and the north part by granodiorite. There occurs high temperature hot spring of which temperature is up to $72^{\circ}C$. The Rb-Sr isotopic data for the biotite granite define whole-rock isochron ages of $207{\pm}70$ Ma with initial Sr isotopic ratio of 0.7132 in north part and $132{\pm}50$ Ma with initial Sr isotopic ratio of 0.7125 in south part, suggesting that the magma be derived from the crustal source material. The geochemical characteristics of the biotite granite and hornblende granodiorite indicate that they were crystallized from calc-alkaline under syn-collisional tectonic environment. The samples of hot spring were collected at March 2005 and March 2006. The $^{87}Sr/^{86}Sr$ ratios of hot spring are 0.714507 and 0.714518, respectively and correspond to those oi the granite being occurred at the south part. The similarity of $^{87}Sr/^{86}Sr$ ratios between the granite and hot spring strongly suggests that the hot spring might be derived from the Seokmodo biotite granite.

• Applied Microscopy
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• v.37 no.4
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• pp.231-238
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• 2007

Although the biological significance of the antennal sensillae to millipedes are widely understood, the structure and function of the antennal sensillae are still not clear and more precise analysis is required. Thus, this study initiate to reveal the fine structural characteristics of various sensory receptors on the antennae of millipede Oxidus gracilis were observed with field emission scanning electron microscopy(FESEM). The antennae generally include eight segments, called articles. On the surface of the antennae, there are a variety of sensory receptors which include olfactory and mechanical receptors. We could identify four different types of antennal sensillae in O. gracilis as follows: apical cone sensilla, trichoid sensilla, chatiform sensilla and basiconic sensilla. The most prominent is four large spital cone sensillae on distal tip of the 8th article. Both of trichoid and chaetiform sensillae are abundantly observed at the most of antennal articles. These sharply pointed structures are inclined and slightly curved toward the apex of the sensilla. The basiconic sensilla are further divided into three subtypes: large basiconic sensilla($Bs_1$), small basiconic sensilla($Bs_2$) and spiniform sensilla($Bs_3$). The $Bs_1$ is located at the 5th and 6th articles, while the $Bs_2\;and\;Bs_3 can be seen at the 5th and 7th articles, respectively.

• Applied Microscopy
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• v.40 no.2
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• pp.101-108
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• 2010

Vitex negundo is an aromatic plant which releases a unique scent due to the presence of essential oil stored presumably within glandular trichomes. The focus of this research was to study developmental patterns of glandular trichomes in Vitex negundo leaves using electron microscopy. There are two types of glandular trichomes which develop on the leaf epidermis of Vitex negundo, peltate glandular type (PT) and capitate glandular type (CT). Structural features differ significantly depending on size and density, formation of secretory cavity, plastid, etc during developmental stages. In young leaves, undifferentiated PTs are densely distributed in the upper epidermis, but are not externally exposed in the lower epidermis because they are covered by non-glandular simple trichomes. Upon leaf development, PTs and CTs show clear structural differentiation in the upper and lower epidermis. PTs are composed of up to eight head cells (ca. 35~40 ${\mu}m$) and one stalk cell (ca. 5 ${\mu}m$), while CTs are composed of four head cells (ca. 10~15 ${\mu}m$) and 1~2 stalk cells (ca. 10 ${\mu}m$). Although secretory cavities develop on the secretory head cells, their size, structure, and formation proceed very differently depending on trichome type. In early development of PT, a large cavity with numerous secretory vesicles form rapidly from the head cells. In CT, however, only a small secretory cavity is formed, slowly relative to PT, without secretory vesicles. The PTs are considered to play an important role in releasing the aromatic components of Vitex negundo.

• Journal of the Korean Society of Child Welfare
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• no.53
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• pp.1-23
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• 2016

With using a subsample of 1,373 poor single mothers and their children from the Fragile Families and Child Wellbeing study, the present study examined the associations among mothers' economic hardship, depressive symptoms, and parenting stress, child abuse and neglect, and their children's behavior problems, delinquency, and social skill. These families were tracked through follow-up interviews at the time of birth, and when the children were three, five, and nine years old. The results indicated that mothers' economic hardship, depressive symptoms, and parenting stress were significant predictors to determine their children's abuse and neglect. Findings also suggest that higher levels of child abuse and neglect are positively associated with more behavior problems and delinquency, and negatively associated with social skills. Further discussions include policy and services to prevent child abuse and neglect and to alleviate mothers' financial difficulties, depression, and parenting stress.

• Korean Journal of Social Welfare Studies
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• v.47 no.1
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• pp.261-290
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• 2016

The purpose of this study was to examine how previous grandmaternal child care affects contacts between older mothers and their adult children. This study especially focused on intergenerational long-term reciprocity relationships. In this study, data from the first wave (in 2006) to the forth wave (in 2012) of Korean Longitudinal Study of Ageing yielded a sample of 1,925 elderly mothers and 7,460 adult children. This study employed multi-level analyses considering hierarchical structures between the mothers and their adult children. In this study, past grandmaternal child care was measured by providing care behavior and unit of time for care. Intergenerational contacts was measured by frequency of face-to-face and non-face-to-face contacts. The results showed that adult children who previously received child care from their mothers were more likely to contact to their mothers. Additionally, the increasing amount of time for elderly mothers to provide care to their grandchildren led to more frequent contacts between elderly mothers and their adult children. The findings proved that grandmaternal child care was in important position in reciprocal relationships between elderly mothers and their adult children. Through these results, this study suggested theoretical, policy, and practical implications.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.14-21
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• 1997

This experiment was conducted to identify the growth and yield differences in rice cultural types: Broadcasting on flooded paddy surface(BF), drilling on flooded paddy surface(DF), puddled-soil drill seeding(PD), drill seeding on dried paddy flat(DD), and machine transplanting of lO-day old seedling(MT) at National Honam Agricultural Experiment Station in 1995. Among the cultural types of direct seeding, the number of seedling stand showed high in order of DD>BF>DF>PD. Tillering at early growth stage was faster in MT and effective tiller showed higher in MT than in direct seeding. Growth duration from seeding to heading was longer in direct seeding than in MT for 2-13 days of Dongjinbyeo and 10-18 days of Nonganbyeo. Root distribution ratio at the surface soil revealed high in order of BF>DF>PD>DD and MT. Culm wall thickness of 4th internode was thicker in machine transplanting of 10-day old seedling than in direct seeding, and the depth of buried culm showed deep by turns of MT> DD>PD>DF and BF. The height of center gravity and moment related to lodging revealed higher in direct seeding than machine transplanting that resulted high lodging index by turns of BF>DF>DD> PD among the direct seeding cultural type. Lodging was occured seriously in the order of BF>DF>PD>DD =MT in Dongjinbyeo but wasn't significantly different in Nonganbyeo among the cultural type. The yield components and grain yield showed varietal differences but was not significantly different between in MT and in direct seeding, and among cultural types of direct seeding.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.71-80
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• 2020

As societies become hyperconnected, we need more cyber security experts. To this end, in this paper, based on the analysis results of the real world cyber attacks and the MITRE ATT&CK framework, we developed CyTEA that can model cyber threats and generate simulated cyber threats in a cyber security training system. In order to confirm whether the simulated cyber threat has the effectiveness of the actual cyber threat level, the simulation level was examined based on procedural, environmental, and consequential similarities. in addition, it was confirmed that the actual defense training using cyber simulation threats is the same as the expected defense training when using real cyber threats in the cyber security training system.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1939-1943
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• 2008

저수지 수질은 유역의 점오염원 배출부하와 강우시 발생하는 비점오염부하 발생에 의한 유역유출수의 저수지 유입과 저수지내 상황 및 기상등에 많은 영향을 받는다. 이와같이 저수지 수질은 저수지 내외의 다양한 요인에 따라 그 특성을 달리함으로 수질관리를 위해서는 기상, 수리 수문, 수질, 지형, 오염원, 처리시설 등 많은 자료를 필요로 하게 된다. 따라서 각종자료의 입력, 수정 및 분석을 하는 자료관리시스템, 수질모의를 수행하는 모델시스템 그리고 분석결과를 표나 그래프로 표현하는 체계를 하나의 시스템으로 통합 구축하여 필요한 분석을 실시함으로서 여러 가지 대안에 대한 평가를 시각적으로 쉽게 할수 있게 되어 관리자는 보다 정확하고 신속하게 의사결정을 할 수 있게 된다. 본 논문에서는 UML(Unified Model Language)기반 하에서 Visual $C^{++}$ 언어를 사용하여 Class diagram, 화면명세, Database명세 등을 생성하는 체계적인 시스템을 구축하였으며, 수질모의를 위해 유역모델로 HSPF 모형을 선정하였고 저수지 모델로는 CE-QUAL-W2를 적용하였다. 구축된 시스템의 활용을 위해 유역관리 시나리오 4개(하폐수처리장 운영에 따른 수질변화모의, 점오염원 제거시 수질모의, 비점오염원 제거시 수질모의, 개발지 관리에 의한 수질모의)와 저수지관리 시나리오 4개(저수지 운영조건 변화에 따른 수질모의, 조류 차단막 설치에 의한 수질모의, 조류제거선 운영에 따른 수질모의, 빈도강우시 탁수관리 모의)를 적용하여 수질변화를 모의하였으며, 다양한 새로운 시나리오를 원활한 적용할수 있도록 설계하였다. 이상의 적용결과로 평가해 볼 때 본 시스템은 저수지 수질관리에 활용할 수 있는 효율적인 시스템으로 평가되었다.