Understanding the behavior of soil under cyclic loading conditions is essential for assessing its response to seismic events and potential liquefaction. This study investigates the effect of non-plastic fines content (FC) on excess pore pressure generation in medium-density sand-silt mixtures subjected to strain-controlled cyclic direct simple shear (CDSS) tests. The investigation is conducted by analyzing excess pore pressure (EPP) ratios and the number of cycles to liquefaction (Ncyc-liq) under varying shear strain levels and FC values. The study uses Jumunjin sand and silica silt with FC values ranging from 0% to 40% and shear strain levels of 0.1%, 0.2%, 0.5%, and 1.0%. The findings indicate that the EPP ratio increases rapidly during loading cycles, with higher shear strain levels generating more EPP and requiring fewer cycles to reach liquefaction. At 1.0% and 0.5% shear strain levels, FC has a limited effect on Ncyc-liq. However, at a lower shear strain level of 0.2%, increasing FC from 0 to 10% reduces Ncyc-liq from 42 to 27, and as FC increases further, Ncyc-liq also increases. In summary, this study provides valuable insights into the behavior of soil under cyclic loading conditions. It highlights the significance of shear strain levels and FC values in excess pore pressure generation and liquefaction susceptibility.

This study aims to measure sedimentation status change with the changes in internal pressure for dry chemical extinguishers of various use periods and analyze the suitability of the fire extinguishers' performance criteria. When the internal pressure of the fire extinguisher is 0%, 2 out of 10 new dry chemical powders for the 5 elapsed years were noted to be suitable, including 3 recycled dry chemical powders with 5 elapsed years that were found eligible. One out of 10 new dry chemical powders for 10 elapsed years was shown as suitable. Also, one new dry chemical powder for 13 elapsed years was suitable. When the internal pressure of the fire extinguisher was 50%, all 10 out of 10 new dry chemical powders for 5 years, recycled one with 5 elapsed years, and a new one with 10 elapsed years were found to be suitable, while 9 new dry chemical powders for 13 years were shown as suitable. When the internal pressure of the fire extinguisher was normal, new ones with 5 elapsed years, recycled ones with 5 elapsed years, new ones with 10 elapsed years, and new ones with 13 elapsed years were all 10 out of 10 samples noted as suitable. In summarizing the experiment results, it was found that the sedimentation status, one of the fire extinguisher's physical properties experiments, affects the fire extinguisher's performance criteria rather than the change with use periods.

In this study the characteristics of wind pressure that are depending on the open type of retractable dome roof were analyzed according to the wind pressure coefficient and wind pressure spectrum. The analysis results showed that the open type and shape of the roof both had a significant impact on the wind pressure changing. In case of the edge to center open type, the wind pressure has not changed much because of the complex turbulence of flow and open area. On the other hand, in case of the center to edge open type, it has confirmed that wind pressure increases due to the separation of flow in windward and open area.

This study investigates the wind pressure characteristics of elliptical plan retractable dome roof. Wind tunnel experiments were performed on spherical dome roofs with varying wall height-span ratios (0.1~0.5) and opening ratios (0%, 10%, 30% and 50%), similar to previous studies of cirular dome roofs. In previous study, wind pressure coefficients for open dome roofs have been proposed since there are no wind load criteria for open roofs. However, in the case of Eeliptical plan retractable dome roof, the wind pressure coefficient may be largely different due to the presence of the longitudinal direction and transverse direction. The analysis results leads to the exceeding of maximum and minimum wind pressure coefficients KBC2016 code.

The biggest impact on the cladding design of buildings is wind loads. Wind tunnel tests were conducted to examine the applicability of current wind load standards about membrane retractable roof spatial structure. A dome model with a circular shape that is retractable to the center of the dome was made (Opening ratio = 0, 10, 30, 50). In addition, height adjustable turntables were made and tested with five patterns with H/D = 0.1, 0.2, 0.3, 0.4 and 0.5. The maximum wind pressure coefficient and the minimum wind pressure coefficient for the cladding were analyzed and the experimental wind pressure coefficient were compared with the current wind load standards, KBC2016 and AIJ-RLB(2015). The experimental value and the reference value of the enclosed roof were very similar and showed possibility of application, but opened roof case was found that the reference value was underestimated.

Background: The active knee extension (AKE) test commonly used to assess the flexibility of the hamstring muscles. Many researchers have tested the reliability of the AKE test; however, no published studies have examined the intrarater and interrater reliability of the AKE test using a PBU. Objects: The purpose of this study was to determine the intrarater and interrater reliability of the AKE test performed with a pressure biofeedback unit (PBU) on healthy subjects. Methods: Sixteen healthy male participants volunteered and gave informed consent to participate in this study. Two raters conducted AKE tests independently with a PBU. Each knee was measured twice, and the AKE testing was repeated one week after the first round of testing. Results: The interrater reliability’s intraclass correlation coefficients (ICC2,1) were .887∼.986 for the right knees and .915∼.988 for the left knees. In addition, the intrarater (test-retest) reliability (ICC3,1) values ranged between .820∼.915 and .820∼.884 for Raters 1 and 2, respectively. The values for the standard error of mesurement were low for all tests (.81∼2.97˚); the calculated minimum detectable change was 2.24∼8.21˚. Conclusion: These findings suggest that the AKE test performed with a PBU had excellent interrater and intrarater reliability for assessing hamstring flexibility in healthy young males.

중공사형 정밀여과(MF)와 한외여과(UF)를 포함한 가압식 막여과 시스템은 높은 수준의 병원균 제거 효율로 인해 음용수 처리에 점점 더 많이 사용되고 있다. 그러나 가압식 막여과 시스템에서 분리막의 손상으로 인한 막완결성의 문제가 발생 시 병원체가 유출될 수 있으므로, 효과적인 온라인 또는 오프라인 방식의 막 완결성 모니터링 방법을 통해 수질의 안정성을 보장하여야 한다. 최근 막 완결성 시험 중 하나 인 압력손실시험(pressure decay test, PDT)이 가압식 분리막 모듈을 이용한 음용수 처리 시설에 적용되고 있다. 이 논문에서는 PDT의 기체 주입방법에 따른 세 가지 조건으로 원수 측, 여과수 측, 원수 여과수 양 뱡향 측 세 가지 조건을 선정 후 이에 따른 감지감도를 이론값과 실험값을 적용하여 비교하였다. 실험결과 가압되는 측의 부피와 감도는 반비례함을 확인하였고, 주입부의 반대방향에 부압을 형성 시에도 감도가 증가함을 확인할 수 있다. 즉 막 손상의 감 지감도는 주입되는 부분의 체적이 작아질수록, 분리막을 경계로 유입과 여과 측의 압력차가 클수록 높아짐을 알 수 있었다.

Using a high-rise building water piping after hydrostatic test of the reliability of the leak to be completed if the pressure is maintained until the leak is not commercially available considered. Due to the nature of high-rise buildings and the construction period will take several years from the lower levels of use of the water supply and fire fighting water pipe construction is in progress, the order of which I do most of the first pipe to the construction and more than three years. So kind of riser pipe is complete, install the valve in the basement by installing an automatic pump to maintain a constant pressure after hydrostatic test and after each floor plumbing piping is complete, the progress of the hydrostatic test without undergoing a separate branch pipe the valve is opened automatically when the number of the pressing pressure of the structure. I kind of do and keep working pressure of pipe until the completion of the construction work to keep the damage to human error when it is intended to prepare. In winter, the frost protection and an alternative to drainage water pipe is damaged or deformed, even if unaware of the finishing work to the building, the use of the damage caused by a leak in a after construction of finish work to be expected. Alternative to reduce this damage if the pressure test without fear of freezing to help maintain long-term commercial pressures may be considered.

바람에 의한 초고층 건축물의 거동은 매우 복잡하기 때문에 구조체에 대한 풍하중의 설계는 매우 어렵다. 현재 사용되고 있는 풍하중 산출방법은 풍동실험에 의존하고 있으며, 1차 탄성거동을 전제로 행해지고 있다. 가장 불리한 조건인 1차 모드로 가정하는 것은 다소 과대설계가 되어 안전하지만, 비경제적이다. 따라서 초고층 건축물에 작용하는 풍하중은 다차 모드 해석에 의해 산출하는 것이 안전성과 경제성을 동시에 확보할 수 있는 방법일 것이라 판단된다. 다차 모드를 고려한 풍하중의 산정은 풍압적분법(Pressure Integral Method)을 응용하면 가능하다. 본 연구는 풍압적분법(Pressure Integral Method)의 유효성을 검증하는 것이 목적이며, 공력진동실험에 의한 풍응답 해석결과와 비교하여 그 유효성을 검증하였다.

Fuel test loop is an irradiation test facility which can conduct the irradiation tests of nuclear fuels and materials at HANARO. The FTL simulates the operating conditions of commercial nuclear power plants such as their pressure, temperature, flow and water chemistry to conduct the irradiation and thermo-hydraulic tests. The passivation of the fuel test loop was performed for the main cooling system in the commissioning stage with satisfaction of the operation criterion such as temperature and water chemistry conditions. The experimental results show that the passivation was completed successfully.

The In-Pile Section(IPS) is located inside the reactor pool. It is divided into 3-parts; the in-pool pipes, the IVA(IPS Vessel Assembly) and the support structures. The test fuel is loaded inside a double wall, inner pressure vessel and outer pressure vessel, to keep the functionality of the reactor coolant pressure boundary. The IVA is manufactured by local company and the functional test and verification were done through pressure drop, vibration, hydraulic and leakage tests. A IVA has been manufactured by local technique and have finally tested under high temperature and high pressure. The IVA and piping did not experience leakage, as we have checked the piping, flanges, assembly parts. We have obtained good data during the three cycle test which includes a pressure test, pressure and temperature cycling, and constant temperature.

The Fuel Test Loop(FTL) which is capable of an irradiation testing under a similar operating condition to those of PWR(Pressurized Water Reactor) and CANDU(CANadian Deuterium Uranium reactor) nuclear power plants has been developed and installed in HANARO, KAERI(Korea Atomic Energy Research Institute). It is consisted of In-Pile Section(IPS) and Out-of Pile System(OPS). The IPS which is localed inside the pool is divided into 3-parts; they are in-pool pipes, IVA(IPS Vessel Assembly) and the support structures. The test fuel is loaded inside a double wall, inner pressure vessel and outer pressure vessel, to keep the functionality of the reactor collant pressure boundary. The localization of the IVA is achieved by manufacturing through local company and the functional test and verification were done through pressure drop, vibration, hydraulic and leakage tests. The brazing technique of the instrument lines has been checked for its functionality and yield. A IVA has been manufactured by local technique and will be finally tested under out of the high temperature and high pressure test.

아스팔트 포장은 점탄성재료로서 포장체에 발생되는 토압은 차량하중의 크기와 재하속도, 아스팔트 포장층의 온도와 하부층의 재료구성에 따라 크기와 분포 양상이 다르게 발생된다. 본 연구는 이러한 다양한 조건에 따른 포장체 하부의 토압분포를 분석하고, 기층과 보조기층의 지지력을 평가하는 평판재하시험 기준과 실제 계측된 토압과의 비교를 통해 현재 적용되고 있는 지지력기준에 대한 타당성을 검토하고자 한다. 또한 실제 포장단면을 모사한 유한요소해석을 통해 포장체 하부에 발생되는 토압을 예측하고 계측결과와 비교함으로서 포장체의 거동을 예측할 수 있는 모델을 제안 하고자 한다. 이를 위해서 시험도로의 2004년 8, 9, 11월과 2005년 8월에 계측이 수행된 아스팔트 포장 동적재하시험 결과 중 계측기 상태가 양호한 A5, A7, A14, A15 단면에 대해 계측결과의 분석을 수행하였다. 토압계의 분석은 차량하중의 크기와 속도. 아스팔트 포장의 온도, 포장하부의 재료구성에 따른 토압의 크기 변화와 차량하중으로 인한 포장체 내부의 횡방향과 깊이방향 하중의 영향 범위를 분석하였다. 포장체의 유한요소해석은 ABAQUS 프로그램을 활용하였으며, 실제 포장체의 거동을 모사하기 위해 시험도로 포장단면을 그대로 반영하고 계측이 이루어진 당시의 온도계측 자료를 활용해 아스팔트 포장의 물성을 적용하였다. 토압계의 분석결과 차량의 하중이 크고 저속으로 주행 할 때 토압의 크기는 증가하고 아스팔트층의 온도가 높을수록 하중의 영향반경이 작아지고 최대 토압크기는 증가하였다. 또한 실제 포장단면과 물성을 적용한 해석결과 계측결과와 매우 유사한 형태의 토압분포와 크기를 보였다. 그리고 기존 보조기층 및 동상방지층의 다짐관리 기준은 실측된 토압과 비교해 볼때 상당히 높은 수준으로 나타났다.

컨테이너 크레인에 대한 풍하중 분포를 조사하기 위하여 대기경계층풍동에서 풍압실험이 수행 되었다. 본 풍압실험의 목적은 크게 두 가지로서 (1) 구조해석을 위한 입력 풍하중 데이터, (2) 전산유동 해석을 위한 표면압력분포 데이터를 확보하기 위한 것이다. 1/70으로 축소된 모형에 464개의 압력공을 설치하여 표면 압력 분포를 구하였다. 국부적인 지점의 압력값 으로부터 표면위의 평균 풍하중을 산정하기 위하여 직육면체의 모형을 제작하여 면의 경사도에 따른 압력값과 하중값의 비를 실험적으로 구하였다. 크레인형상의 특성과 관련하여 레이놀즈수의 영향, 압력튜브시스템의 설계 등에 관하여 논의한다.