The automatic dust separator is a device installed in the suction tank of the pumping or drainage plant, and prevents foreign substances such as aquatic plants or wood chips from being sucked into the underwater pump. Since the dust separator obstructs the flow of water for separating dusts, a water level difference is likely to occur before and after the dust separator. Since the water level difference before and after the dust separator acts as an additional hydraulic load on the dust separator structure, it may reduce the lifetime of the dust separator and cause damage. In this study, in order to reduce the water level difference, we devised changing the existing I-beam-shaped dust separator parts to a streamlined shape, and quantitatively analyzed the water level difference before and after the dust separator, hydraulic load, and flow velocity distribution through computational fluid analysis to confirm the effect of design improvement.

When the nuclear accident like the Fukushima is occurred, it is required to immediately determine the location of radioactive materials and their activities. Various studies related the unmanned technique to detect and characterize the contaminated area have been conducted. The Korea Institute of Nuclear Nonproliferation and Control (KINAC) has developed a new gamma detection system which consists of nine probes using a silicon photomultiplier (SiPM) and plastic scintillator. The probe is the small gamma detector designed to be carried and dropped near the accident area by the unmanned aerial vehicle. In this paper, we developed the improved design related to the angular dependence of the radioactive contamination detection system with the purpose of increasing the detection efficiency. The detection efficiency, radiation shielding and back-scattering varies depending on the direction of incidence of radiation because the probe has vertical structure of consisting scintillator, photomultiplier, and electric circuits. That is, when the experimental conditions are same except the direction of gamma probe, the result of measurements is different. It causes errors in measuring the radioactivity and location of the radioactive source. Since the direction of the probe is arbitrarily determined during the deployment of the probe through the unmanned aerial vehicle, it is considered changing the design of the scintillator from a conventional 1.0" × 1.0" Φ cylindrical shape to a 1.0" Φ spherical shape. In case of using the spherical scintillator, it is confirmed that angular dependence was reduced through MCNP simulation. The difference in the measurement depending on the direction of the probe could be reduced through additional structure design. Finally, we hope that the developed detection system which has the probes with spherical shape of scintillator can measure the radioactivity and location of the radioactive source in a range of about 100 × 100 m2 by measuring for at least 5 minutes. The field test at Fukushima area will be carried out with JAEA members in order to prove the feasibility of the new system.

본 연구의 목적은 비데를 아이템으로 선정해 시니어의 특성과 니즈를 충족시키기 위한 제품기반 서비스디자인을 제안하는데 목표를 두고 진행하였다. 최근 초고령화가 급속히 진행되고 있으나 시니어에 대한 이해가 부족하고, 시 니어를 위한 PSS 개념의 서비스디자인 연구가 미흡한 편이다. 본 연구에서는 4D 더블 다이아몬드 디자인 프로세스 모델을 활용하여 시니어의 특성과 니즈를 반영한 ‘시니어 중심의 비데 제품서비스디자인’ 개선방안을 제안하고자 한다. 연구의 방법은 PSS 개념에 기반하여 ‘4단계 더블 다이아몬드 디자인 프로세스 모델’을 활용하였다. 이를 위해 시니어 대상 질적 리서치를 수행하여 시니어의 특성과 니즈에 따른 사용자 가치 요소를 도출하였으며, 이를 기반으 로 제품서비스 아이디어를 발굴하여 실무 전문가 그룹의 유용성 리뷰를 반영한 프로토타입을 제안하였다. 연구의결과는 첫째, ‘사용자 맞춤 기능 설정 가이드 스마트 앱 서비스’를 제안하였다. 사물인터넷(IoT) 기술을 접목한 비데 와 스마트 폰이 연동되어 사용자 특성 정보와 비데 제품에 대한 정보를 자동으로 해석하여 맞춤 기능을 가이드해주 는 앱 서비스를 제시하였다. 둘째, ‘사용자 중심의 제품서비스 인터페이스’를 적용한 조작부 및 리모컨 UI를 제안하 였다. 시니어의 사용성 및 인지능력을 고려하여 주 기능 중심의 구성과 과업(Task) 순서에 따른 버튼 배치, 터치 화면 형 리모컨 등 단순하고 직관적인 Physical UI를 제안하였다. 셋째, 정기적인 제품 점검뿐만 아니라 사용자 건강 및 사용 공간의 위생, 청결 등 폭넓은 서비스를 제공하는 ‘제품과 헬스/위생 케어가 연계된 비데 케어서비스’를 제안하 였다. 결론적으로 사용자(시니어)의 비데 제품 사용 과정(사용 전-중-후)에서의 페인포인트(Pain Point) 및 요구를 발 견하고 개선하여 사용자 경험과 관계 품질을 향상시킬 수 있는 제품기반 서비스디자인 방법론을 제안하였다.

PURPOSES : The logistic roads for freight transport along to the new port of Busan have been suffered by the rapid weather changes including high temperature and torrential rain. As a result, the roads require annual repair, which have been distressed seriously by the heavy logistic and environmental loads. Therefore, we need to identify the cause of the road pavement distresses and find a proper design method to minimize the pavement distress in order to prohibit the problem aggravated. METHODS : The damaged conditions of the logistic roads were investigated on-site. In addition, applied pavement designs, real traffic volumes, and historical climatic information were intensively collected for this project. With the investigated and collected data Korean pavement design program (KPRP) was implemented to analyzed the causes of the damaged roads and conceive the pavement design draft optimized for the roads. RESULTS : According to the investigation and KPRP analysis, the traffic volume to transport freights impacts significantly the pavement distress, so that a higher PG grade binder type should be used, for which polymer modified asphalt (PMA) binders are recommended. Moreover, its pavement thickness should be increased to secure load bearing capacity, but thickening the pavement has been discouraged due to difficulties induced by the road-sectional change, especially road-height change. CONCLUSIONS : In conclusion, 5cm PMA overlay is suggested for the normal-scale maintenance, and 7cm PMA overlay for large-scale maintenance. Besides these, the application of Polymer-modified Stone Matrix Asphalt (PSMA) using PG76-22 binder would be the best preventive maintenance method, which has been well know as having higher fatigue resistant performance than general PMA. However, if we use PSMA, quality control should be very cautious since PSMA can be very susceptible premature distress if its production and construction are improperly proceeded.

At ship design stage, the maneuverability is generally estimated based on the empirical formula or the computational fluid dynamic (CFD), which is one of the numerical simulation methods. Using the hydrodynamic derivatives derived through these methods can quantitatively estimate the maneuverability of target vessels and evaluate indirect maneuverability. Nevertheless, research on estimating maneuverability is insufficient for ships not subject to IMO maneuverability standard, especially fishing vessels, and even at the design stage, the empirical formula developed for merchant ships is applied without modification. An estimation error may occur due to the empirical formula derived from the regression analysis results of a model test if the empirical formula developed for merchant ships with different hull shapes is applied to fishing vessels without any modification. In this study, the modified empirical formula that can more accurately estimate the fishing vessel's maneuverability was derived by including the hull shape parameter of target fishing trawlers in the regression analysis process that derives Kijima et al. (1990) formula. As a result, the modified empirical formula showed an average estimation error of 6%, and the result improved the average error of 49% of Kijima et al. (1990) formula developed for merchant ships.

In a previous paper, ambient vibration tests were conducted on a cable stayed bridge with resilient-friction base isolation systems (R-FBI) to extract the dynamic characteristics of the bridge and compare the results with a seismic analysis model. In this paper, a nonlinear seismic analysis model was established for analysis of the bridge to compare the difference in seismic responses between nonlinear time history analysis and multi-mode spectral analysis methods in the seismic design phase of cable supported bridges. Through these studies, it was confirmed that the seismic design procedures of the “Korean Highway Bridge Design Code (Limit State Design) for Cable Supported Bridges” is not suitable for cable supported bridges installed with R-FBI. Therefore, to reflect the actual dynamic characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure is proposed that applies the seismic analysis method differently depending on the seismic isolation effect of the R-FBI for each seismic performance level.

In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the “Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges.” Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

Worldwide plant market keeps maintaining steady growth rate and along with this trend, domestic plant market and its contractors also maintain such growing tendency. However, in spite of its external growth, win-win growth of domestic material industry that occupies the biggest share in plant industry cost portion is extremely marginal in reality. Domestic plant material suppliers are required to increase awareness of domestic material brand by securing quality and reliability of international standard through improvement of design quality superior to that of overseas material suppliers. Improvement of design quality of plant material becomes an essential element, not an option, for survival of domestic plant industry and its suppliers. Under this background, in this study, priority and importance by each evaluation index was analyzed by materializing plant design stage through survey of experts and defining evaluation index by each design stage and based on this analysis result, evaluation index of stage-gate based decision-making process that may improve design quality of plant material was suggested. It is considered that by utilizing evaluation index of stage-gate based decision-making process being suggested in this study, effective and efficient decision-making of project decision-makers would be enabled and it would be contributory to improve design quality of plant material.

When domestic sewage and rainwater runoff are discharged into a single sewer pipe, it is called a “combined sewer system.” The sewage design standards in Korea specify the flow velocity based only on the volume of rainfall; therefore, sedimentation occurs on non-rainy days owing to the reduced flow rate and velocity. This sedimentation reduces the discharge capacity, causes unpleasant odors, and exacerbates the problem of combined sewer overflow concentration. To address this problem, the amount of sewage on non-rainy days, not just the volume of rainfall, should also be considered. There are various theories on sedimentation in sewer movement. This study introduces a self-cleansing velocity based on tractive force theory. By applying a self-cleansing velocity equivalent to the critical shear stress of a sand particle, sedimentation can be reduced on non-rainy days. The amount of sewage changes according to the water use pattern of citizens. The design hourly maximum wastewater flow was considered as a representative value, and the velocity of this flow should be more than the self-cleansing velocity. This design method requires a steeper gradient than existing design criteria. Therefore, the existing sewer pipelines need to be improved and repaired accordingly. In this study, five types of improvement and repair methods that can maximize the use of existing pipelines and minimize the depth of excavation are proposed. The key technologies utilized are trenchless sewer rehabilitation and complex cross-section pipes. Trenchless sewer rehabilitation is a popular sewage repair method. However, it is complex because the cross-section pipes do not have a universal design and require continuous research and development. In an old metropolis with a combined sewer system, it is difficult to carry out excavation work; hence, the methods presented in this study may be useful in the future.

2018년 여름의 폭염은 기상관측을 시작(1907년 10월 1일)한 이래 111년 만에 가장 높은 기온을 기록하였는데, 서울은 39.6℃를 기록(2018년 8월 1일)하여 종전의 기록인 38.4℃(1994년 7월 24일)를 뛰어넘었다. 열섬현상으로 인해 도시의 온도가 상승하고 하절기 열쾌적성이 저하됨에 따라 하절기 열환경 개선에 대한 연구가 지속적으로 진행되고 있다. 본 연구의 목적은 조경공 사 전·후의 온도저감 및 외부공간 이용자가 느끼는 열환경 개선에 대하여 정량적으로 검증하여 설계 및 시공단계에서 활용할 수 있는 기초적 자료를 제공하고자 하였다. 연구결과는 다음 과 같다. 미기후 실측에 의한 측점별 조경공사 전·후의 온도저감을 비교 분석한 결과, 오전 10 시 조경공사 전 평균온도는 34.5℃이며, 조경공사 후 평균온도는 32.5℃로 2.0℃온도저감 효과가 있는 것으로 분석되었으며, 오후 2시 조경공사 전 평균온도는 37.5℃이며, 조경공사 후 평균 온도는 35.9℃로 1.6℃ 온도저감 효과가 있는 것으로 분석되었다. 오후 5시 조경공사 전 평균온 도는 33.8℃이며, 조경공사 후 평균온도는 31.2℃로 2.6℃ 온도저감 효과가 있는 것으로 분석되었다. 연구결과의 활용방안으로 정량적인 연구방법과 결과는 디자이너의 직관적인 조경설계에 객관성을 부여하는 기초자료로서 활용이 가능할 것이다.

Contemporary people want to develop their bodies to enhance quality of life. Although weight-training machines have been mainly developed with this trend based on intuition and experience, this study attempted to improve and verify those products through computer simulations using the musculoskeletal model of the human body. An arm-curl machine, a weight-training machine for arm exercise, was chosen for this research and the improved exercise effects were observed. The existing exercise that moves the scapula on the axis of the elbow with raised forearm is effective for biceps but not for triceps and adjacent muscles. Thus we suggested the idea for a new concept arm-curl machine that also raises the scapula after raising the forearm. To verify the effects of this new exercise, we manufactured arm-curl linkage. The experiments found that the exercise effects of the biceps were maintained, and the exercise effects of the triceps remarkably improved. These findings verified the effects of the proposed new concept arm-curl linkage.

Recent changes in the construction method of piles to minimize noise, along with the development of high-strength reinforcement, have provided an economical high performance RC pile development to compensate for the disadvantages of existing PHC piles. In this study, a methodology for the development of cross - section details of high performance RC piles of various performances is presented by freely applying high strength steel and concrete. This study suggested a technique for calculating bending moments for a given axial force corresponding to the allowable crack widths and this can be used for serviceablity check. In calculating the design shear force, the existing design equation applicable to the rectangular or the I section was modified to be applicable to the hollow circular section. In particular, in the limit state design method, the shear force is calculated in proportion to the axial force, and the procedure for calculating PV diagram is established. Last, the section details are determined through PM diagrams that they have the similar flexural and axial-flexural performances of the PHC pile A, B and C types with a diameter of 500 mm. To facilitate the application of the selected standard sections to the practical tasks, the design PM diagram and design shear forces are proposed in accordance with the strength design method and limit state design method.

A steering knuckle for a car is a key part of a corner module and is a functional part connected to steering, suspension, and braking devices. Steering knuckles are used for various types of forging and machining methods such as casting forging, aluminum forging, etc. to perform productivity and quality. Therefore, in this study, we study about the development of the overall design of the steering knuckle in the production and supply of the steering knuckle for the product processing method, quality, assembly inspection, etc. through the modeling and analysis of the steering knuckle.

The diesel engine generate many pollutants such as PM(Particulate matter) and NOx(Nitrogen oxide). So the SCR(Selective catalytic reduction) must be required to meet the emission standard. The SCR catalyst market is growing rapidly, and the automobile markets using alternative energy sources are growing rapidly. This study deals with optimization of the calcination process the manufacturing process of SCR catalyst to be competitive. The calcination process is a bottleneck and it is required to optimize productivity and accept to be safety, But we cannot trade off anything in terms of safety. We applied DOE(Design of experiments) among many research methods performed in various fields. In order to achieve quality and productivity optimization. The dependent variables in the DOE were selected as NO Conversion(%). The independent variables were selected as the calcination temperature, soaking time and fan speed RPM. the CCD(Central composite designs) constructs response surface using the data onto experience and finds optimum levels within the fitted response surfaces. Our tests are our stability guarantee and efficient together with operation.