• Journal of the Korea Concrete Institute
• /
• v.15 no.6
• /
• pp.848-855
• /
• 2003

During concrete placement, the partially distributed load due to the concrete placement paths creates the lateral force in the connection parts of the shore. In order to restrain this lateral force, the nails must be used in the upper and lower connection parts of shores. But, for the convenience of the construction and dismantling of the shores, the workers hardly use the nails. In this case, the connections of shore cannot resist the shear force and rotation. And this situation may cause the collapse of form-shore system. Therefore, contact and spring models for the connection analysis of the form-shore systems are required. If we take into account this construction situation, we need to understand the effects of shear and rotation stiffness according to the several types of connection parts in shores as a case study. This study evaluates the shear and rotation stiffness of the connection parts of shores according to the variations of the lengths, numbers and positions of nails, and then presents the experimental results depending on the end conditions of shores. And, these results can be used as a spring model and critical load evaluation data for the connection analysis of form-shore system.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.1
• /
• pp.58-66
• /
• 2020

Implant-Assisted Removable Partial Dentures (IARPDs) treatment is being performed in a fully edentulous patient using implant surveyed prosthesis as an abutment. Implant-supported prosthesis as an abutment of IARPDs is classified into screw-retained and cement-retained type according to the retention type, and each has advantages and disadvantages. The EZ crown system (Samwon DMP, Yangsan, Korea) has a cylinder combined with abutment, and the nickel-titanium spring in this cylinder provides a constant force on the zirconia ball to obtain retention in EZ crown system. In this patient, the natural abutment teeth of the mandibular overdenture was hopeless. We planned implant assisted removable partial denture using anterior implant surveyed prosthesis considering functional and esthetical rehabilitation, cost and patient's needs. When fabricating IARPDs using implant as abutment, we could compensate for the shortcomings of existing implant-supported prosthesis retention type and made the design of removable partial denture easy due to using EZ crown system.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.1
• /
• pp.78-85
• /
• 2004

The new biotelemetry method and system that the installation and the treatment of equipment is convenient and the instantaneously detailed position of the fish attached a pinger is able to track comparatively easily had been developed, an practicality of it were verified in the water tank and the small sea port through the tracking of fish. The biotelemetry method had been gotten the three dimensional locations of fish to the receiving transducer by combining of the super short base line (SSBL) method to detect the direction of pinger and the pinger synchronizing method to measure the range from receiving transducer to pinger. The receiving system had been designed to realize the high precision or wide detection range by application of the basic design method for receiving system of biotelemetry and the hydrophone array configuration. From tracking test of carp in the water tank, the migration course and the velocity of carp was investigated and the observed migration course was compared with measurement. The measured migration course of carp coincided with the observation in the main and the position of carp was able to track three dimensionally. The velocity of carp measured by the moving average method was 11.2cm/s. From tracking test of yellowtail in the small sea port, the migration course and the velocity of yellowtail was investigated at natural condition. The position of yellowtail was able to track three dimensionally and the velocity of it measured by moving average method was 43.9cm/s.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.317-324
• /
• 2020

Combined cycle power plants (CCPP) that use natural gas as fuel are easier to start and stop, and have lower pollutant emissions, so their share of domestic power generation facilities is steadily increasing. However, CCPP have a high concentration of nitrogen dioxide (NO2) emission in the initial start-up and low-load operation region, which causes yellow plume and civil complaints. As a control technology, the yellow plume reduction system was developed and operated from the mid-2000s. However, this technology was unable to control the phenomenon due to insufficient preheating of the vaporization system for 10 to 20 minutes of the initial start-up. In this study, CFD analysis and demonstration tests were performed to derive a control technology by injecting a reducing agent directly into the gas turbine exhaust duct. CFD analysis was performed by classifying into 5 cases according to the exhaust gas condition. The RMS values of all cases were less than 15%, showing a good mixing. Based on this, the installation and testing of the demonstration facilities facilitated complete control of the yellow plume phenomenon in the initial start-up.

• Journal of the Korean Society of Radiology
• /
• v.12 no.2
• /
• pp.277-287
• /
• 2018

Pelvic floor muscle is the main sub-system that maintains urinary continence. The weakness of pelvic floor muscles causes the stress urinary incontinence, and therefore the degree of functioning of pelvic floor muscles could be used as an index to assess the degree of stress urinary incontinence. In this study, the quantitative diagnosis algorithm was proposed to estimate the degree of stress urinary incontinence (SUI) by measuring the contraction pressure of pelvic floor muscle. For these reason, the contraction pressure measurement system from pelvic floor muscle was developed, and the measuring protocol was suggested to analysis the obtained data. As the results of clinical test, the proposed diagnosis algorithm shows the 80% of accuracy, and 20% of false positive diagnosis. On the other hand, false negative results were not confirmed. Consequentially, we thought that the proposed urinary incontinence diagnosis algorithm can quantitatively diagnose the progression of the stress urinary incontinence and it can be used for the development of the incontinence diagnosis system.

• Journal of Korea Spatial Information System Society
• /
• v.2 no.2 s.4
• /
• pp.59-74
• /
• 2000

Because efficiency of the 1st-phase NGIS investment(1995-2000) has not been clearly measured, the action taken in the 2nd-phase NGIS project requires NGIS budgets to be evaluated in terms of effectiveness. Especially, the effective investments in local governments are critical for the NGIS projects, because they execute the much larger amount of budgets in total than other GIS projects. As indicated, for the successful NGIS implementation, it is important to obtain continuous political and financial supports from decision makers. As a persuasion measure for the budget appropriation, CBA(Cost-Benefit Analysis) and CEA(Cost-Efficiency Analysis) can play an important role for the decision makers. The major concern of this paper is how to measure the costs and benefits of the GIS implementation by considering important characteristics of the GIS projects in local governments, and existing theories are reviewed for this concern. The GISs in local governments can have different stages in terms of its evolution and the effectiveness of the applications can be represented variously. To identify categories for measuring costs and benefits of the various GISs, case studies and success stories are reviewed from both the foreign and domestic research. The categories of costs and benefits are determined from the tangible and intangible aspects. The categories for the quantitative and qualitative measure are proposed to evaluate the GISs in local governments. After measuring costs and benefits, three key evaluation methods in cost-benefit analysis are suggested as follows: 1) the benefit: cost ratio (B/C), 2) Internal Rate of Return (IRR), and 3) the net present values (NPV) of the costs and benefits. The sensitivity and uncertainty analysis are also helpful to make a decision for the GIS budget appropriation in local governments. In conclusion, although cost-benefit analysis is not an easy undertaking, it is certain that it can play an important role in the future for the GIS funding decisions in local governments.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.1
• /
• pp.190-198
• /
• 2018

In recent years, non-welded building hardware has been installed by bolt assembly is used. The non-welded building hardware method can reduce accidents caused by welding, and can be constructed by bolt assembly, which can reduce labor costs and shorten the construction period. However, there is a need for a method to compensate for the occurrence of buckling at the time of construction. The purpose of this study is to evaluate the behavior of joints between steel pipe and fastener and to evaluate the behavior of joints of non-welded and welded hardware frame. As a result, it was found that the foundation steel structure without welded joints was deformed to a rotation angle of member much larger than the allowable interlayer displacement angle 0.01 to 0.02 required according to the seismic load rating in the seismic load resistance system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.545-553
• /
• 2021

The frequency by water disaster in urban areas are increasing continuously due to climate change and urbanization. Countermeasures are being conducted to reduce the damage caused by water disasters. An analysis based on permeability, one of the parameters that affect runoff, is needed to predict quantitative runoff in urban watersheds and study runoff reduction. In this study, the SWAT model was simulated for the oncheon stream basin, a representative urban stream in Busan. The permeability map was prepared by calculating the CN values for each hydrologic response unit. Based on the permeability map prepared, EPA SWMM analyzed the effect of LID technology application on the water cycle in the basin for short-term rainfall events. The LID element technology applied to the oncheon stream basin was rooftop greening in the residential complex, and waterproof packaging was installed on the road. The land cover status of the land selected based on the permeability map and the application of LID technology reduced the outflow rate, peak flow rate, and outflow rate and increased the infiltration. Hence, LID technology has a positive effect on the water cycle in an urban basin.

• Tribology and Lubricants
• /
• v.35 no.1
• /
• pp.44-51
• /
• 2019

The paper presents the rotordynamic performance measurements and model predictions of a fuel cell electric vehicle (FCEV) air compressor supported on gas foil bearings (GFBs). The rotor has an impeller on one end and a thrust runner on the other end. The front (impeller side) and rear (thrust side) gas foil journal bearings (GFJBs) are located between the impeller and thrust runner to support the radial loads, and a pair of gas foil thrust bearings are located on both sides of the thrust runner to support the axial loads. The test GFJBs have a partial arc shim foil installed between the top foil and bump strip layers to enhance hydrodynamic pressure generation. During the rotordynamic performance tests, two sets of orthogonally installed eddy-current displacement sensors measure the rotor radial motions at the rotor impeller and thrust ends. A series of speed-up and coast-down tests to 100k rpm demonstrates the dominant synchronous (1X) rotor responses to imbalance masses without noticeable subsynchronous motions, which indicates a rotordynamically stable rotor-GFB system. Finite element analysis of the rotor determines the rotor free-free (bending) natural modes and frequencies well beyond the maximum rotating frequency. The predicted damped natural frequencies and damping ratios of the rotor-GFB system reveal rotordynamic stability over the speeds of interest. The imbalance response predictions show that the predicted critical speeds and rotor amplitudes strongly agree with the test measurements, thus validating the developed rotordynamic model.

• Proceedings of the Korean Society for Information Management Conference
• /
• 2017.08a
• /
• pp.100-100
• /
• 2017

100년의 역사를 지닌 한국지질자원연구원(KIGAM)은 국내 유일의 지질자원 전문연구기관으로서 그간 생산한 조사 연구데이터는 우리나라 과학기술의 귀중한 역사적 학술적 가치가 큰 유산으로써 보존 가치가 매우 크다고 할 수 있다. 하지만 현재 KIGAM의 상황은 최종성과물 위주로 자료관리가 이루어지고 있으며, 조사 연구 과정에서 생산된 암석 토양 지하수샘플이나 조사 탐사장비를 통해 얻어지는 자료는 연구자 또는 연구실 팀에서 개별적으로 관리하고 있다. 이러한 자료관리체계는 자료의 공동 활용이 어렵고, 자료를 보유하고 있는 연구자의 퇴직이나, 조직개편으로 인한 팀 실의 분리 과정에서 자료의 손실과 훼손 가능성이 높고, 누가 어디에 어떤 자료를 무슨 형태로 보관하고 있는지 찾기 어려워 자료의 재활용도가 떨어질 뿐만 아니라, 이로 인한 중복 조사 연구 가능성도 배제할 수 없다. KIGAM은 지질자원분야 국가데이터센터 구축을 목표로 연구과정에서 생산되는 연구데이터의 체계적인 관리와 공유, 활용체계 구축을 위해 2015년도에 기획사업을 통해 중장기 로드맵을 포함한 추진전략을 수립하였으며, 한국과학기술정보연구원(KISTI)의 DataNest를 기술이전받아 지질자원 연구데이터 리포지토리 시스템(GDR: Geoscience Data Repository)를 개발하였다. GDR 시스템 개발을 위해 연구데이터 분류코드를 작성하였으며, 2016년부터 데이터관리계획(DMP: Data Management Plan)을 주요사업 연구계획서 양식에 포함시켜 제출하도록 하였다. 과거 KIGAM은 연구데이터를 수집, 관리하기 위해 몇 차례에 걸쳐 시도를 했지만 실패한 경험을 가지고 있다. 실패 요인에는 (1) 관련 정책, 제도, 조직, 인력, 예산 등 데이터 관리 인프라 부재, (2) 연구사업에서 생산된 데이터는 개인소유라는 인식 및 공유 의식 부족, (3) 데이터 관리 활동은 귀찮은 것이고, 시간 낭비라는 인식, (4) 데이터 관리 공개 공유 활동에 대한 보상체계 부재 등을 꼽을 수 있다. 즉, 제도를 포함한 인프라 부족과 경영진과 구성원의 인식부족이 제일 큰 원인으로 판단된다. 성공적인 연구데이터 관리를 위해서는 지속적이고 꾸준한 투자가 이루어져야 하지만 경영진의 의지에 따라 사업이 중단되기도 한다. 이러한 과거의 실패 요인에 대한 해결 없이 지난 1년 6개월 정도의 GDR 운영은 지지부진하였다. 이러한 문제점을 해결하기 위해서는 국가차원의 제도적 뒷받침이 따라야 한다. 즉 국가 R&D 성과물 관리차원에서 연구데이터를 주요 성과물로 관리해야 할 것으로 판단된다. 연구사업계획서에 DMP를 포함시키고, 연구주제 및 분야별로 데이터센터(혹은 데이터 리포지토리)를 지정하고, 국가 R&D에서 생산되는 연구데이터를 의무적으로 제출하도록 하는 것이다. 또한 데이터센터의 안정적이고 지속적인 운영을 위해 연구사업비 항목에 데이터 관리비를 신설하여 데이터센터의 운영비로 사용하도록 하면 예산문제도 어느 정도 해결 될 수 있을 것으로 본다. 또한 데이터 제출 및 인용도에 따라 데이터 생산부서 혹은 생산자에게 평가점수를 부여하는 등 보상체계 마련을 위한 연구도 필요할 것으로 보인다. 국가 R&D 연구데이터의 수집, 관리, 공유, 활용을 제대로 성공시키려면 국가 R&D 최고정책결정자의 지속적인 관심과 지원이 필수적이다.