• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.42-51
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• 2003

The global demand for underground facilities has increased substantially in the past decades, and a substantial number of underground projects have had to deal with challenging ground conditions in urban environments. Particularly challenging are weak and unstable water bearing soils. Advancements in shielded TBM tech-nology have led to significant improvements regarding the ability to control ground deformations in soft ground. Nonetheless, ground collapse may occur even when the most advanced TBM designs are employed if unexpected adverse ground conditions are encountered or if insufficient stabilizing pressure is transferred to the tunnel face. This paper reviews common approaches for face stability and face pressure transmission calculations, and provides an overview of some of the latest technological developments and considerations for soft ground TBM applica-tions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.96-101
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• 2001

Recently, with the increasing of construction works, large construction equipment are used to reduce the term of work and labor cost in construction field. Therefore, construction equipment noise has caused much annoyance for a number of dweller in nearby construction field and it has become a very serious problem in our living environment. Neverthless, in our country, adequite guidelines for the construction equipment noise are very deficiency because of the lack of basic data and insufficient research works. From this point of view, this study attempts to survey the vertical SPL distribution of piling noise by oil pressure method in construction field. This study also present a basic data found a effective plans for piling noise by oil pressure method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.173-187
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• 2022

Recent studies have focused on self-management of hypertension using smart devices (cellular phones, tablets, watches). It has proven to be an effective tool for early detection and control of high Blood Pressure (BP) without affecting patients' daily routines. This systematic review surveys the existing self-monitoring systems, evaluate their effectiveness and compares the different approaches. We investigated the current systems in terms of various attributes, including methods used, sample size, type of investigation, inputs/ outputs, rate of success in controlling BP, group of users with higher response rate and beneficiaries, acceptability, and adherence to the system. We identified some limitations, shortcomings, and gaps in the research conducted recently studying the impact of mobile technology on managing hypertension. These shortcomings can generate future research opportunities and enable it to become more realistic and adaptive. We recommended including more observable factors and human behaviors that affect BP. Furthermore, we suggested that vital monitoring/logging and medication tuning are insufficient to improve hypertension control. There is also a need to observe and alter patient behavior and lifestyles.

• 한국화재소방학회논문지
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• 제24권2호
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• pp.97-105
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• 2010

압력차를 이용한 연기제어기법은 피난계단 또는 대피공간으로 연기의 유입을 방지하기 위한 방법 중 가장 많이 알려져 있다. 그럼에도 불구하고 국내에서는 기술에 대한 이해부족에 기인한 많은 문제점이 발생하고 있다. 그러한 관점에서 차압제연설비의 성능에 영향을 미치는 주요인자인 풍도면적, 급기댐퍼의 개구면적, 부속실 개방에 따른 영향, 연돌효과 그리고 급기주입구의 위치가 시스템의 성능에 어떠한 영향을 미치는지를 분석하였다. 중요한 결론으로는 풍도의 단면적이 작을수록 마찰손실이 증가하여 적절한 차압을 유지할 수 없었으며, 특히 연돌효과는 저층부의 압력차를 작게 만들어 차압제연시스템의 성능을 약화시키는 가장 큰 요인으로 확인되었다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.1-1
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• 2000

The infinite layer compound $ACuO_2$, (A-Alkaline earth) consists of infinite stacking of $CuO_2$ planes separated only by alkaline earth ions. This compound attracted much attention because it contains only key ingredient of all cuprate high temperature superconductor; $CuO_2$ plane with controllable carrier concentration without charge reservoir block. High pressure synthesis method has been found to be preferable for this system due to its ability of doping various lanthanide ion into A site with larger superconducting volume fraction. But rigorous study on this rudimentary compound has been hindered by insufficient quality of sample. Especially superconductlng volume fraction was often too small to identify its origin. In this presentation, we report high pressure synthesis of $Sr_{0.9}Ln_{0.1}CuO_2$ (Ln=La, Sm). By controlling the heating temperature precisely during high pressure synthesis we could have superconductors with quite high superconducting volume fraction for this compound. The magnetic properties of the graln aligned samples show very different behavior compared to the cuprate high temperature superconductors. Details will be discussed.

• 한국화재소방학회논문지
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• 제28권2호
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• pp.40-47
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• 2014

NFSC103의 배관스케줄방식으로 설계하는 경우, 작동면적 내의 헤드 약 50%가 최소요구량에 못미치는 문제점을 해결하기 위하여 NFSC103과 NFPA13의 배관스케줄방식을 비교, 분석하였으며 NFSC103의 유량부족 문제를 해결할 수 있는 새로운 방법을 제시하였다. 각 헤드에서의 소화수방출량을 기존의 80 L/min의 150%인 120 L/min으로 하면 수리계산한 값을 상회하여 모든 헤드에서 최소기준값인 1 bar, 80 L/min을 충족하게 된다. 이는 누구나 쉽게 배관스케줄방식으로 설계할 수 있으며 설계면적 내의 모든 헤드가 최소요구량을 충족하는 최적의 방법이다.

• 한국자동차공학회논문집
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• 제24권1호
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• pp.90-98
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• 2016

Currently government certified test method for an automobile remanufactured products is insufficient. Thus many automotive parts in the remanufacturing market are lacking proper evaluation criteria and production of defective products are causing customer dissatisfaction. In this paper a power steering oil pump, which requires stringent manufacturing standards, is studied by the failure mode and effect analysis approach. The research suggested that the test criteria such as discharge flow characteristic test, tightness test, pulley run-out test, pressure switch operation test, low temperature test and rotation pressure durability test should be performed to evaluate the reliability of remanufactured power steering oil pumps. As a result of tests, the performance of remanufactured power steering oil pump satisfied the evaluation criteria of pressure switch operation test and low temperature test. However, the remanufactured power steering oil pump failed to satisfy the evaluation criteria on discharge performance test, tightness test and pulley run-out test. These performance evaluation tests proved the necessity of standard process for the remanufactured power steering oil pump.

• Geosystem Engineering
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• 제21권6호
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• pp.318-325
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• 2018

Eight tight sandstone reservoir samples from $He_8$ and $Shan_1$ Formations of the Sulige Gas field were selected to perform gas-water micro-displacement experiment based on authentic sandstone micro-model. The gas pressure-relief experiment was proposed for the first time to simulate the pressure change and gas-water percolation characteristics in the process of gas exploitation. The experiment results show that: (1) In the process of gas accumulation, the gas preferentially flows into the well-connected pores and throats with large radius, but rarely flows into the area without pores and throats. (2) Under sufficient gas drive, the water in pores and throats usually exists in the forms of 'thin water film', 'thick water film', and 'water column', but under insufficient gas drive, gas fails to flow into new pathways in time, so that the reservoirs with large pores and throats are high in water cut. (3) Under the same water saturation, the reservoirs with better petrophysical properties has higher gas recovery factor within unit time. Under the same petrophysical conditions, the reservoirs with lower water saturation show higher gas recovery factor within unit time. The higher the permeability, the stronger the liquid carrying capacity of reservoirs.

• Physical Therapy Rehabilitation Science
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• 제11권3호
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• pp.329-334
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• 2022

Objective: Low back pain (LBP) is a symptom that accounts for a large proportion of musculoskeletal pain. Among them, non-specific LBP (NSLBP) means that the pathological cause is unknown, and belongs to the most common LBP. Studies on the mechanism of muscle control in LBP are insufficient, and quantitative studies are needed. Design: Observational cross-sectional study design Methods: A Thirty participants with NSLBP symptoms were enrolled, and their pressure pain thresholds (PPT) and muscle and fat thickness were measured. Participants measured the paraspinal muscles (PM) of the thoracic and lumbar spine and medial hamstring (semitendinosus) on the dominant and non-dominant sides in the prone position. Results: Among the variables that were significant in the correlation analysis, PM of the thoracic and lumbar spine showed a significant relationship in the PPT ([thoracic spine PM]=1.141+0.912 [lumbar spine PM]). Also, there was a significant relationship between the lumbar spine PM in the PPT and the thoracic spine PM in the muscle thickness ([lumbar spine PM of PPT]=4.057+0.117 [thoracic spine PM of muscle thickness]) Conclusions: Although there was no muscle imbalance according to the dominant and non-dominant side, there is a correlation between the pressure pain threshold and the muscle thickness between the paraspinal muscles of the thoracic spine and the lumbar spine.

• 천문학회보
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• 제44권2호
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• pp.36.4-36.4
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• 2019

Ricci et al. (2017, Nature, 549, 488) discovered a lack of high accretion rate, obscured Active Galactic Nuclei (AGN) in the hard X-ray selected Swift/BAT local AGN survey. This was interpreted as radiative pressure driven AGN feedback clearing its immediate vicinity composed of dusty gas (having an effectively low Eddington limit in the order of 0.01-0.1), and governing the level of nuclear obscuration. As we find Eddington-limited accretion and high extinction values among obscured, luminous AGN (quasars) however, it may be that the local X-ray AGN and the distant quasars undergo different feedback mechanisms in clearing their surroundings. In this study, we simply compare the obscuring column density and Eddington ratio values for quasars selected by various methods, including X-ray obscured, optically blue, infrared red/luminous, and submillimeter bright AGN. We find obscured quasars lying on the column density-Eddington ratio diagram previously unoccupied by Ricci et al., suggesting that radiative pressure is insufficient to clear its dusty structure at high luminosity, or that the dust in obscured quasars are more extended than the low luminosity counterparts to become fully transparent. We discuss alternative feedback scenarios that may be more relevant for obscured quasars.