• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.299-299
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• 2023

토양수분(soil moisture)은 수문인자의 하나로서 토양 내에 함유된 물의 양을 의미하며, 그 총량은 미미하지만 대기와 지표면 사이에서 일어나는 복잡한 물순환과 에너지 교환을 이해하는데 있어 필수적이다. 현재 국내에서는 「수자원의 조사·계획 및 관리에 관한 법률」(이하 수자원법)에 근거해 토양수분량 관측이 이루어지고 있으며, 수자원 분야의 한국수자원조사기술원 외에도 농업, 임업 분야에서도 다양한 기관에서 지상관측소를 구축해 토양수분량을 측정하고 있다. 국내 지상관측소에서는 주로 지점규모(point scale)로 토양수분량을 관측하는 장비가 사용되고 있으며, 유전율식 장비인 TDR(Time Domain Reflectometry), FDR(Frequency Domain Reflectometry)이나 토양수분장력을 측정하는 장력계(Tensiometer)가 널리 쓰이고 있다. 수자원분야에서는 토양 내 수분의 양을 직관적으로 확인할 수 있는 유전율식 장비가 대중적으로 사용되고 있으며, 최근에는 우주선(Cosmic-Ray)으로부터 발생하는 고속중성자(Fast Neutron)를 통해 중규모 면단위(field scale) 토양수분량을 관측하는 장비인 CRNP(Cosmic-Ray Neutron Probe)에 대한 연구도 활발히 진행되고 있다. 이러한 장비는 주로 야외에 설치해 운영하고 있기 때문에 장비 훼손이나 전원공급의 어려움으로 결측이나 오측이 발생할 수 있다. 토양수분량 시계열자료의 결측이나 오측이 일반적인 감쇄기에 발생했다면 선형보간법으로도 간단히 보간할 수 있지만, 강우에 의한 상승기에 발생했다면 해당 강우사상에서의 토양수분량의 상한치를 알기 어려워 결측보간에 어려움이 있다. 본 연구에서는 토양수분량 시계열자료의 강우기간 결측을 보간하는 방법으로 누적분포함수 역변환 샘플링방법을 선택하였다. 연구에는 음성군(차곡리) 토양수분량 관측소 2021년 자료가 사용되었으며, 관측소 56개 지점 중 임의의 지점에 결측구간을 생성한 뒤 해당 지점과의 상관계수가 높은 지점의 누적분포함수를 이용해 역변환 샘플링 방식으로 임의 지점의 결측을 보간하고 그 결과를 기존값과 비교해 보간 방법의 정확도를 평가하였다.

• Journal of Practical Engineering Education
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• v.16 no.2
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• pp.179-184
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• 2024

Printed circuit boards (PCBs) are a key component widely used in the production of electronic products, and not only quantitative growth but also qualitative developments such as integration cannot be ignored. Wave soldering equipment is commonly used equipment at manufacturing sites, but it is impossible to configure a dedicated equipment environment suitable for each PCB specification during the preliminary research and prototype development stage. It is neither suitable for development within limited time line nor manufacturing various product groups because only equipment setting conditions can be changed within a given time. In this study, we introduce a case of introducing a PCB pallet to enable selection of optimal process conditions within the limited environment described above. In addition, by presenting a discriminant that can determine in advance whether production is possible with current general-purpose equipment, it is expected that problems that may arise due to limitations in the general-purpose wave soldering equipment environment can be identified and resolved in advance. Ultimately, this palette makes it possible to shorten the development period and improve productivity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.381-388
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• 2015

Global Maritime Distress and Safety System (GMDSS) equipment and Electronic Chart Display & Information System (ECDIS) are typical equipment which help seafarers to obtain information for ship's safe navigation. In this study, a survey on using of GMDSS equipment and ECDIS was conducted on a total of 260 ship masters and crew who have been working on ocean-going vessels. The subjects were asked about the usage, and level and reason of satisfaction or dissatisfaction of GMDSS equipment and ECDIS, the leading navigational system from which they receive information. The survey showed that the third- and fourth-most frequently used equipment, MF/HF and INMARSAT (telex), were deemed to be the second- and third-most useless equipment. It means that the frequency of device usage is not proportionate to the level of navigational safety. Especially, 'ease of device use (42.3%)' and 'necessity of the provided information (50%)' were highlighted as factors increasing the level of satisfaction with the system. The survey result shows that ship safety cannot be realized by only adopting advanced systems, technology and services. It emphasizes the need to consider the level of 'accessibility and appropriateness of the information' and 'ease of device use'. Discussions implemented by the IMO on various policies and regulations are aimed at securing ship safety. In order to achieve the goal, such institutions should be validated by end-users and relevant studies should be conducted.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.271-277
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• 2013

The subjects of this study were the patients of H Dental Hospital in Busan, who visited for the purpose of treatment in patients over 18 years of age and 151 patients, analyzed the data of the results of the selection criteria of the dental health care consumer. The gender of the subjects by cross-analysis, importance order of selection criteria for dental hospital were cleanness and hygiene(78.1%), equipment and facilities(60.9%), career and word-of-mouth(57.6%), staff kindness(57.6%), ease of use(32.5%) and scale of dental hospital(22.5%), it was appeared similar in comparison of cross-analysis and average-analysis. Major consideration of the study subjects to select criteria for dental hospital was pain control(31.8%), infection control(30.5%), cost(29.8%), time(7.9%) respectively. Gender as a primary consideration to the part of a man in pain control(39.2%), women cost(39.1%) was most common (p<0.001). In dental health care consumer to select criteria, clean hygiene and infection control at the heavily appeared to affect the direction of change in the consciousness of consumers seeking and it is necessary to improve hospital services for the dental care of their qualitative changes.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.605-613
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• 2014

The purpose of this study is studying the relationship among experience choice, experience effect and experience satisfaction of marine leisure sports for the vitalization of marine leisure tourism. After preparing a questionnaire, investigation and analysis were done by visiting Boryeong area. The result of the study is as following. First, it was found that the major cause of choice in marine leisure sports has positive impact on choice satisfaction. Second, it was found that the major cause of choice has positive impact on experience effect. Third, it was found that the choice satisfaction in marine leisure sports has positive impact on experience effect. Fourth, it wa s found that the marine leisure sports visitors like motor boat, banana boat and yacht experience. Fifth, it is suggested that an equipment rental desk, safety facilities and marine leisure experience facility included in a marine leisure experience center to be built.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.251-260
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• 2020

Unlike manned aerial vehicles, because an unmanned aerial vehicle (UAV) has a limitation which allows only remote test during flights, it is very important to maintain the high reliability of the vehicle through pre- and post-flight tests. To this end, this paper designed an air vehicle test equipment (AVTE) for UAV which meets the derived hardware and software requirements. Based on this design, the AVTE was implemented in accordance with the actual test scenario. The implemented AVTE has the advantage of reducing the time and cost required for the test of UAV by allowing the operator to perform automatic or manual tests for necessary parts in various situations such as before and after starting engine and pre- and post-flight tests. Furthermore, this study is expected to help with the design and implementation of AVTE for other UAVs.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.2
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• pp.157-163
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• 2002

The aim of this study is to establish an evaluation function that can be used in comparison of alternative layouts by quantification of particularities of arrangements. The machinery arrangement is a design phase that decides the location of various equipment in a compartment to make the most of the function of every components and to meet the limit of ship space at the same time. In case of the ship, Only one of the several alternative layouts is selected. This process depends on the experience, knowledge, and judgement of an expert and, as a result of it, it's hard to get an objective evaluation. Therefore, according to quantification by using the fuzzy theory, we suggest a standard that can objectively evaluate alternative layouts.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.430-433
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• 2011

산불 진화에 사용되는 지상 주력 장비를 대상으로 수원으로부터 호스 거리 및 고도에 따른 성능을 정량화하기 위한 현장 적용 실험을 실시하였다. 대조군으로는 담수지 형태의 수원을 사용하고 수원으로부터 고도차가 40m 수준인 예비실험을 대상으로 성능값을 비교하였다. 본 현장 적용 실험에서는 산림 내 계곡지를 수원으로 하였으며, 고도차가 150m 로 예비실험의 3.75배인 지형을 선택하였다. 고도에 따른 영향이 크지 않은 예비 실험과 비교하였을 때 고도가 높아질수록 동일 거리에서 측정한 성능값은 평균 50% 이상의 감소를 나타내었다. 그러나 수평 및 수직 거리는 20% 이내 수준의 감소를 나타내어 진화에 큰 장애 요소로는 작용하지 않았으며, 펌프압력은 소형펌프의 압력 상승이 가장 큰 상승률을 나타내었다. 이와 같은 결과는 수원의 형태에 따라 용수 공급차에 기인한 것으로 안정적 용수공급 저하, 펌핑압 부하 증가, 이물질 삽입 등이 원인인 것으로 사료되며, 고도에 따른 영향 인자도 반영된 것으로 해석된다. 또한 실험을 통해 진화장비별 실제 진화대원의 적정 사용거리와 거리별 적정 소요인원을 산출할 수 있었다.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.93-98
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• 2010

본 연구에서는, 반도체, LCD 공정에서 금속막을 증착하기 위하여 PECVD장비에 화재, 폭발 위험성과 독성을 가진 Silane가스를 사용하게 되는 장비인 gas cabinet, pipeline, VMB(Valve manifold box), MFC(mass flow controller)장비 등, 전반적인 시스템에 대하여 영국 HES의 ALARP개념을 도입하여 위험성 평가를 실시하여 문제점을 도출하고 대책을 강구 하는데 목적이 있고, 여러 가지 문제점중 절대적으로 수용 할 수 없는 Critical Risk로는 Gas Cylinder를 사용하여 Silane을 공급하고자 할 때에는 필히 Gas Cabinet을 사용하여 공급하여야 하고, Tube Trailer를 사용하여 공급하고자 할 때에는 필수적으로 Purge System을 갖추어 공급하여야 한다. 선택적으로 수용할 수 있는 High, Medium Risk로는 Gas Cylinder 또는 Tube Trailer를 사용하여 Silane을 공급하고자 할 때는 Inlet 부분에 RFO(Resticted Flow Orifice)를 설치하여 사용하고 Gas Supply Room에는 CO2소화설비를 적용하지 말고 Water Mist등 물 분무설비를 적용하여야한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.3
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• pp.167-175
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• 2007

The relations between data from test methods and conditions in structural elements are considered. NDE(Nondestructive Evaluation) methods are joint application of a test and a basis for interpretation of data obtained in the test. Correct assessments of conditions of elements depend on the inaccuracy and variability in the test data and on the uncertainty of correlations between attributes(what is measured) and conditions(what is sought in the inspection). A full description of the performance of NDE methods considers the relation of test data to condition of elements. The quality of the test data itself is important, but equally important is the interpretation that occurs after the test. To make the decision of the performance of NDE methods, this paper presents mathematical basis to measure the reliability of NDE methods.