• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.538-549
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• 2019

This study suggests a new platform in which VI can communicate with their guardians who serve as a system administrator optimizing personal characteristics. In terms of interaction between platform components, this study can contribute to enhancing stability of walking by giving substantial information to VI through server processing and setups of guardians with real-time interaction to VI through server processing and setups of guardians with real-time interaction. Therefore, developing smart phone applications can facilitate both portability and cost effectiveness, by the users' downloading the application and registration. In terms of guardians' cost, this system is cost-effective because they can access to the administration system through personal computers or smart phones, not through specialized system devices. This system is web-based, which automatically communicates with the surroundings of, such as provides the guardians with the necessary information or approaches to the danger through IoT devices, which results in enhancing safety. Moreover, it is possible for guardians to utilize the personalized platform since the system not only senses personal characteristics but also sends a number of information to VI. a new platform makes it possible for guardians to provide electronic support and interaction with the application with the application users, which contributes to systematic and safe walk for VI.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.711-721
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• 2022

Due to a long-term pandemic of COVID-19 since 2019, our society finally goes into 'un-tact (non-contact) era' in earnest by increasing an importance of non-contacted activities which are able to live without contacts among people. Un-tact era has influenced to generate a huge structural change with digitalization in our daily life as well as industrial society based on digital twin as an essential technology. As a technology representing real world in virtual digital world by integrating various technologies applied to 4^th industrial revolution, digital twin leads an innovation in industrial society with diverse industrial processes. But this technique isn't actively used across all industries due to structural limitations and environmental restrictions of digital twin. Especially, the field of construction and facility is necessary to use digital twin because it requires periodic managements of buildings in daily life and is directly connected with casualties in cases of disaster. But issues faced in reality are acting as an obstacle for applying digital twin. Therefore, this study suggests the necessity applying digital twin in facility safety response based on these issues and emphasizes active applications of digital twin by describing the expected effects being created. Furthermore, it connects to create demands of digital twin by overcoming current issues and suggesting high sustainable development.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.281-287
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• 2009

An eruption failure can be observed for child and adolescent periods when the primary dentition is changed to the permanent dentition through the mixed dentition frequently. The eruption failure can lead to miss erupting times of the tooth, then it will cause a lot of problems including root resorption, esthetic problem, transposition of adjacent tooth, malocclusoin and etc. Especially, the maxillary first molar is importantly concerned with occlusion and growth and is an essential tooth for development and maintenance of occlusion. So, it is a momentous part of more proper occlusal management to find these abnormal cases at the early stage and solve the problems. The sorts of eruption failures of the maxillary first molars can be divided into delayed eruption, impaction and the primary retention and the secondary retention. When physical obstacles cause impaction, first of all they must be removed then we can treat the impaction with observation after removal, surgical exposure or orthodontic traction. If the source of impaction is an ectopic eruption, the treatment can be a brasswire, a pendulum appliance, a space maintainer or space regainer after the extraction of the second deciduous tooth and etc. These cases are made a diagnosis of eruption failures of the maxillary first molars in mixed dentition period and have good prognosises after my treatments. So I reported them.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1686-1690
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• 2006

현재 우리나라에서는 하천의 개수사업 및 교량, 제방 등과 같은 수공구조물 설계시 계획 홍수위를 산정하는데 있어 실무에서는 1차원 모형인 HEC-RAS 모형이 널리 이용되고 있다. 그러나 HEC-RAS 모형과 같은 1차원 모형의 경우 모형의 한계로 인해 하폭의 확대, 축소, 만곡부 및 섬 등과 같은 장애물 존재시 하천횡단면에 따른 수위 및 유속변화를 표현하는데 많은 어려움이 있으며, 이런 한계로 인해 1차원 모형만을 이용하여 하도 및 하천공간계획을 수립하기란 사실상 불가능하다. 또한 최근 들어 하천기능에 대한 인식이 과거 홍수소통, 용수이용 등 이.치수중심에서 인간과 다양한 생명체가 공존하는 서식처로서의 기능을 부여하는 생태하천의 개념으로 변화하는 추세이며, 이와 같이 변화된 패러다임하에서 생태하천복원사업 등과 같은 하천관련 사업추진 시 합리적인 하도 및 하천의 공간계획을 수립하기 위해서는 하도내 2차원 흐름특성 등과 같은 기초자료가 절실히 요구된다. 따라서, 본 연구에서는 합리적인 하도 및 하천의 공간계획을 수립하기 위한 기초자료를 제공함은 물론, 보 철거에 따른 하도내 흐름개선 효과를 분석하기 위해 연구대상 하천인 두계천에 대하여 2차원 수치모의를 통한 하도내 흐름특성 변화를 조사하였다. 본 연구에서 선정한 2차원 모형으로는 유한요소법에 기반을 둔 RMA-2모형의 범용프로그램인 SMS 모형을 선정하였고, 1차원 수치해석을 통하여 선정된 하류단의 경계조건을 적용하여 2차원 수리특성 분석을 실시하였다. 분석결과 철거대상 취수보 15개에 대하여 보철거 후 수위에 대한 개선 효과는 금암보를 제외한 대부분의 보 철거 구간에서는 그리 크지 않은 것으로 나타난 반면, 보 철거에 따른 유속의 개선효과는 대부분 큰 것으로 나타났다.는 경우보다 낮게 나타나고 있다. On-Line 저류지의 경우 Off-Line 의 경우에 비해 수위, 유량이 저류지의 상류단에서 크게 나타났다. On-Line 저류지의 경우 Off-Line 의 경우에 비해 같은 값의 첨두홍수량을 저류하기 위해서 상대적으로 넓은 저류면적이 필요한 것으로 나타난다. 대등한 수위감소값의 홍수저감효과를 발휘하기 위해서 본 연구에서는 On-Line 저류지 면적은 Off-Line 저류지에 비 두배 이상이 필요한 것으로 보여졌다.들에 관한 정보는 종종 현장관측에서 조차 무시되는 경우가 많다. 이에 본 연구에서는 수질모형의 매개변수 중 특히 수리특성에 관련된 매개변수들이 수질에 미치는 영향을 파악하는 것을 목적으로 하고 있다. 이를 위해 적용된 수질모형은 QualKo를 사용하였으며, 대상 하천은 낙동강 본류 경남구간 시점 부근인 회천 합류 전부터 낙동강 본류 경남구간 종점 부근인 밀양강 합류 전까지의 경남 오염총량관리 기본계획 시 구축된 모형 매개변수를 바탕으로 분석을 수행하였다. 일차오차분석을 이용하여 수리매개변수와 수질매개변수의 수질항목별 상대적 기여도를 파악해 본 결과, 수리매개변수는 DO, BOD, 유기질소, 유기인 모든 항목에 일정 정도의 상대적 기여도를 가지고 있는 것을 알 수 있었다. 이로부터 수질 모형의 적용 시 수리 매개변수 또한 수질 매개변수의 추정 시와 같이 보다 세심한 주의를 기울여 추정할 필요가 있을 것으로 판단된다.변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.158-164
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• 2002

Some of synthetic chemicals can net as an endocrine disrupting substance in higher animals. Dioxins, DDT, PCBs and bisphenol A (BPA) are classified into endocrine disruptors and aye under a strict control in many countries. This research was designed to compare the clastogenic effects of BPA to those of ionizng radiation to establish the relaltive effectiveness of BPA by means of Tradescantia micronucleus assay. For the uptake of the BPA through the stems, groups of fresh cuttings of Tradescantia BNL 4430 weve placed in BPA solutions of 0 to 4 $\mu$M for 6 hours under continuous aeration. The other groups of the cuttings were irradiated with 0 to 0.5 Gy of gamma- rays. The frequencies of micronucleus showed a positive dose- response relationship in the range of 0 to 0.5 Gy, and a clear concentration-response relationship in the experimental range of BPA concentrations. By comparing the two experimental results, it is possible to estimate the BPA concentration and its equivalent radiation dose for a fixed value of MCN frequency. BPA of $ll.8\mu{M}$ can give rise to 53.3 MCN/100 tetrads, which is the same frequency induced by 25 cGy of gamma- rays. It is of biological importance that clinical symptoms start to develop after a whole body exposure to radiation higher than 25 cGy. The results indicate that the pollen mother cells are an excellent biological end- point for toxicity test of suspected endocrine disrupting chemicals such as bisphenol A, cotylphenol and nonylphenol.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.171-178
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• 2015

This research is the first research on developing the speed limit select model and also it is the result of the research on the importance of each element and consideration factors when selecting the speed limit. For the consideration factor discrimination and calculation of the importance, the delphi method and AHP method was used. The delphi survey was processed through third round survey, 5 high consideration factor(Level 1) and 23 low consideration factor(Level 2) was discriminated. During the process of the third delphi survey, when the CVR cost was in the range between 0.4~1.0 it was treated as the consideration factor when selecting the speed limit and less than 0.4 cost was eliminated. In the process of the second delphi survey, 33 consideration factors were discriminated but was reordered into 23 categories through the third survey. Based on the 23 categories earned through the third delphi analysis, the AHP survey was processed. The result of the AHP survey was that out of the importance of the 5 high consideration factor(Level 1), the traffic condition was evaluated as the number one factor and the vessel condition, waterway condition, environment condition, supporting condition and etc. conditions were evaluated following the traffic condition. Out of the 23 low consideration factor(Level 2) consideration, the visibility was evaluated to be the first important and the performance of the vessel steering, objective factors within the harbor, amount of traffic and density, distance between the passing vessel, speed of the steering capacity and tidal current were the following evaluated factors.

• Journal of Mushroom
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• v.15 no.1
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• pp.14-20
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• 2017

The oyster mushroom cultivation house typically has multiple layers of growing shelves that cause the disturbance of air circulation inside the mushroom house. Due to this instability in the internal environment, growth distinction occurs according to the area of the growing shelves. It is known that minimal air circulation around the mushroom cap facilitates the metabolism of mushrooms and improves their quality. For the purpose of this study, a CFD analysis FLUENT R16 has been carried out to improve the internal environment uniformity of the oyster mushroom cultivation house. It is found that installing a section of the working passage towards the ceiling is to maintain the internal environment uniformity of the oyster mushroom cultivation house. When all the environment control equipment - including a unit cooler, an inlet fan, an outlet fan, an air circulation fan, and a humidifier - were operated simultaneously, the reported Root Mean Square (RMS) valuation the growing shelves were as follows: velocity 23.86%, temperature 6.08%, and humidity 2.72%. However, when only a unit cooler and an air circulation fan operated, improved RMS values on the growing shelves were reported as follows: velocity 23.54%, temperature 0.51%, and humidity 0.41%. Therefore, in order to maintain the internal environment uniformity of the mushroom cultivation house, it is essential to reduce the overall operating time of the inlet fan, outlet fan, and humidifier, while simultaneously appropriately manage the internal environment by using a unit cooler and an air circulation fan.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.199-207
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• 2006

Recent global warming seems to be dramatic and has influenced forest ecosystems. Changes in phonology of biota, species distribution range shift and catastrophic climatic disasters due to recent global warming have been observed during the last century. Korean forests located mainly in the temperate zone also have been experienced climatic change impacts including shifting of leafing and flowering phonology, changes in natural disasters and forest productivity, However, little research has been conducted on the impact of climate change on forest ecosystems in Korea which is essential to assess the impact and extent of adaptation. Also there is a shortage in basic long-term data of forest ecosystem processes. Careful data collection and ecological process modeling should be focused on characteristic Korean forest ecosystems which are largely complex terrain that might have hindered research activities. An integrative ecosystem study which covers forest dynamics, biological diversity, water and carbon flux and cycles in a forest ecosystem and spatial and temporal dynamics modeling is introduced. Global warming effects on Korean forest ecosystems are reviewed. Forestry activity and the importance of forest ecosystems as a dynamic carbon reservoir are discussed. Forest management options and challenges for future research, impact assessment, and preparation of mitigating measures in Korea are proposed.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.30-30
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• 2015

유역에 내린 강우의 총량은 홍수나 갈수 측면에서 매우 중요하다. 점 강우량에 의해 측정된 강우량을 이용하여 유역 총강우량으로 환산하는 과정에 많은 오차가 포함되어 있다. 선행연구에 따르면, 우량계를 통한 강우관측에서 언더캐치(undercatch)에 의한 계통오차는 일반적으로 5~16%, 우연오차는 약 5%가 발생된다고 보고하였으며, 점 우량계 자료를 내삽하여 공간자료로 변환할 경우 0.1km 규모에서 표준오차가 4~14%, 1km 규모에서는 33~45%, 10km 규모에서는 약 65% 정도 발생된다고 한다. 이러한 우량계 관측오차 및 강우자료 처리과정에서 발생되는 오차는 유역의 유출량 계산에 영향을 주어 홍수예보 정확도를 크게 떨어뜨릴 수 있다. 우리나라에서는 지금까지 유역 총강우량 산정 측면에서 지점강우량의 불확실성에 대한 연구가 많이 이루어지지 못하였다. 본 연구에서는 우리나라에서 주로 사용되고 있는 전도형 우량계를 이용하여 소규모 구역에서 관측되는 강우관측의 불확실성을 분석하고자 하였다. 연구에 사용된 우량계는 0.5mm 급 표준 전도형 우량계로 정밀도는 시간당 1~100mm 기준으로 ${\pm}1%$를 기록하여 기상검정규격인 ${\pm}3%$를 만족하고 있다. 이 우량계는 한국건설기술연구원 안동하천실험센터 내에 장애물이 없는 평지에 60m 간격으로 총 6대($2{\times}3$)를 설치하여 2014년 7월 11일부터 9월 2일까지 54일간 관측을 수행하였다. 관측기간 동안 2대의 우량계가 수일동안 강우가 기록되지 않아서 분석에서 제외하였다. 우량계 상호 간의 누적강우량(54일간)을 비교한 결과 2.5~25.5mm의 차이를 나타냈다. 강우강도별 강우량 합계를 비교한 결과 시간당 1mm 이상에서는 약 1%의 차이가 났으며, 시간당 15mm 이상에서는 7.4%의 차이를 나타내어 강도가 큰 강우사상에서 우량계 간의 관측오차가 더 크게 나타났다. 또한 우량계 상호 간의 상관계수를 분석한 결과, 우량계 간의 거리가 가까울수록 그리고 누적시간이 길수록 상관계수는 커지는 것을 확인할 수 있었다. 도출된 결과를 토대로 하면 앞서 언급한 바와 같이 점 우량계 자료를 내삽하거나 유역 또는 계산격자의 대푯값으로 사용하여 1시간 이하 단위로 유출모의를 할 경우 심각한 오차를 발생시킬 수 있음을 시사한다. 보다 신뢰성 있는 홍수예보와 효율적인 유역관리를 위해서는 점 중심의 강우 관측이 아닌 면적 우량에 대한 관측이 이루어져야 하며 이를 위한 기술의 개발이 필요하다.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.1-9
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• 2021

Many factors such as wind direction, wind strength, temperature, and obstacles affect a munition's trajectory. Since these factors eventually determines the probability of hit and the hitting point of a target, these factors should be considered to obtain reliable weapon effectiveness data. In this study, we propose the extension of the MSDL(Military Scenario Definition Language) to reflect these factors to improve the reliability of weapon effectiveness data. Based on the existing MSDL, which has been used to set the initial condition of a military simulation scenarios, the newly identified subelements are added in ScenarioID, Environment, Organizations, and Installations as a scenario schema. Also, DamageAssessment and DesignOfExperiments element are added to make weapon effectiveness data easily. The extended MSDL enables to automatically generate the simulation scenarios that reflect various factors which affect the probability of hit or kill. This extended MSDL is applied to an integrated simulation software of weapon systems, named AddSIM version 4.0 for generation of weapon effectiveness data.