• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.674-680
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• 2014

Monitoring systems of informations for ship performance have become important gradually for economical management of existing ship. Monitoring of NOx emission from marine diesel engines is one of them. The measurement of NOx emission, however has been many difficulties due to technical and costly problems. A monitoring by prediction method of NOx on-board ship according to sailing condition of ship could be an useful method. In this paper, it is discussed about modified method of one-zone model which has been utilized usually for analyzing the combustion process. The modified method is able to calculate the temperature of burned region from the result by one-zone model. Influences which excess air ratio during combustion process affected for the gas temperature and NOx emission were investigated. From the results variation of excess air ratio during combustion process could be estimated inversely through the comparison with measurement of NOx emission.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.203-210
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• 2007

As a part of basic studies on monitoring of landslides and slope stability using SP measurements, micro-electric potentials of rock samples were measured accompanied with the rock failure by a uniaxial loading test were measured. The measurement system consists of a 8 channel A/D converter with 24 bit resolution, uniaxial loading tester, strain gages and 4 sets of electrode attached to a rock sample. Rock samples of granite, limestone, and sandstone were tested. Also, mortar samples were tested in order to monitor electric-potentials of a uniform sample. Micro-electric potentials were detected in all saturated samples and the strength of them increased as the loading force increased. Sandstone samples showed the largest strength of micro-electric potential and it followed limestone and granite samples, which indicates a positive relationship with porosity of rocks. The mechanism generating these micro-electric potential can be explained in terms of electro-kinetics. In case of dry samples, micro-electric potential could be observed only in sandstone samples, where piezoelectric effect played main role due to high contents of quartz in sandstone samples. We found that biggest micro-electric potentials were observed at the electrodes near the crack surface of rock samples. This is very encouraging result that SP monitoring can be applied to predicting landsliding or to estimate collapsing position combining with monitoring of acoustic emissions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.914-916
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• 2013

Renewable energy from the environment in a variety of ways to obtain various forms of energy. Recent functional polymer composites (EAP) to take advantage of the pressure and vibration of physical energy into electrical energy storage, to take advantage of current collector technology is attracting attention. EAP, a type of IPMC (Ionic exchange Polymer Composite) got a hydrophilic properties, marine power plants is being studied as a source of energy. Studies using IPMC marine power plant because there is a constraint on the time, IPMC in real time, which can measure the power generated by the system is required, Due to the nature of the power plant to be floating in the sea through the power cable and data transmission measurement system is hard drive self-generation and wireless data transmission system is required. In this study, IPMC marine power plant is to develop a system of monitoring. IPMC for several power plants to build individual current-voltage measurement system, CAN communication with the main system to collect all the information and wireless data transmission to occur, and Generation of electricity using solar energy to building systems in real-time without an external power supply to drive the measuring system is to develop a monitoring system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.63-70
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• 2008

In this paper, a smart sensor system for the MEMS pressure sensor was developed. A compensation algorithm and programmable calibration circuits were presented to eliminate errors caused by temperature drift of piezoresistive pressure sensors in itself. This system consisted of signal conditioning, calibration, temperature detection, microprocessor, and communication parts and these were integrated into a SOC. A RS-232 interface was employed for monitoring and control of a smart sensor system. The area of fabricated IC is $4.38{\times}3.78\;mm^2$ and a $0.35{\mu}m$ high voltage CMOS process was used. Compensation error for temperature drift of 50 KPa pressure sensors was measured into ${\pm}0.48%$ in the range of $-40^{\circ}C{\sim}150^{\circ}C$. Total power consumption was 30.5 mW.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.200-200
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• 2019

본 연구에서는 실제 가압장 및 가압장후단부의 상수도관망에 발생가능한 수충격해석을 수행하고 신뢰성해석을 수행하여 파괴확률을 정량적으로 산정하였다. 이를 위해 가압장의 펌프운영조건을 다르게 적용하였고 관말단부의 압력센서를 이용하여 토출압을 선택적으로 운영하면 수충격의 규모도 작아지고 파괴확률도 대폭 줄어드는 것을 확인할 수 있었다. 가압장의 토출압을 선택적으로 운영하기 위해서는 관말단부에 필수적으로 충분한 수압이 존재해야하며 이를 위해서 실시간 모니터링이 가능한 압력계를 설치하게 된다. 이 압력계로부터 수신되는 데이터를 통하여 펌프의 운영이 이루어지고 최소한의 에너지 사용을 통해 효율을 증대하고 피해율도 저감하게 된다. 본 연구에서 개발된 센서기반 펌프운영시스템이 적용된 실제 상수도관망은 현재 가압장의 운영조건으로 24시간 75m의 펌프 토출압을 유지하고 있으며 관말단부의 수용가에 충분한 수압이 전달되고 있다. 가압장의 고압유지는 관말단부에 충분한 수압을 전달하기 위한 것이지만 상수도관망에서 누수와 시설물에 대한 많은 피해를 유발할 수 있다. 따라서 본 연구에서는 가압장의 펌프토출압을 75m와 60m로 선택적 운영을 할 수 있도록 프로그램을 개발하였다. 기존 가압장의 운영조건과 선택적 운영조건을 사용하여 수충격해석을 수행하였고 신뢰성해석모형을 사용하여 파괴확률을 정량적으로 산정할 수 있었다. 가압장의 운영조건을 최적화하여 효율은 증대하고 피해율을 저감할 수 있는 방법을 찾을 수 있었다. 이를 위해서 가압장의 인버터 설치는 물론이고 펌프의 최적운영을 위해 개발된 펌프운영 프로그램을 가압장 배전반에 장착하여 경제적인 운영이 될 수 있을 뿐만 아니라 실제 상수관망에서 과도한 수압으로 인해 발생할 수 있는 여러 가지 피해를 최소화할 수 있을 것으로 판단된다. 또한, 본 연구에서는 기존의 펌프장 토출압으로 운영되었을 때와 비교하여 에너지 절감율을 정량적으로 산정하여 비교분석하였다. 가압장 후단의 작은 마을을 대상으로 하여 절감된 전기요금은 적은 양이라 할 수 있겠으나 개발된 시스템을 전국에 적용한다면 에너지 절감으로 인한 경제적 파급효과는 크다고 할 수 있다.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.285-297
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• 2022

We report results of Extended Leak-Off Test (XLOT) conducted in a large diameter borehole, which is drilled for installation of deep borehole geophysical monitoring system to monitor micro-earthquakes and fault behavior of major fault zones in the southeastern Korean Peninsula. The borehole was planned to secure a final diameter of 200 mm (or more) at a depth of ~1 km, with 12" diameter wellbore to intermediate depths, and 7-7/8" (~200 mm) to the bottom hole depth. We drilled first the 12" borehole to approximately 504 m deep and installed American Petroleum Institute standard 8-5/8" casing, then annulus between the casing and bedrock was fully cemented. XLOT was carried out for several purposes such as confirming casing and cementing integrity, measuring rock stress states. To that end, we drilled additional 4 m long open hole interval to directly inject water and pressurize into the rock mass using the upper API casings. During the XLOT, flow rates and interval pressures were recorded in real time. Based on the logs we tried to analyze hydraulic conductivity of the test interval.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.241-241
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• 2016

반도체 선폭이 20 nm급까지 감소함에 따라 기존에 수율에 문제를 끼치던 공정 외부 유입 입자뿐만 아니라, 공정 도중에 발생하는 수~수십 나노의 작은 입자도 수율에 악영향을 끼치게 되었다. 이에 따라 저압, 극청정 조건에서 진행되는 공정 중 발생하는 입자를 실시간으로 모니터링 할 수 있는 장비에 대한 수요가 발생하고 있다. Particle beam mass spectrometer (PBMS)는 이러한 요구사항을 만족할 수 있는 장비로 100 mtorr의 공정 조건에서 5 nm 이상의 입자의 직경별 수농도를 측정할 수 있는 장비이다. PBMS로 입자의 수농도를 측정하기 위해서는 PBMS 전단에서 입자를 중앙으로 집속할 필요가 있다. 공기역학렌즈는 PBMS 전단에서 입자를 집속시키기 위해 일반적으로 널리 사용되고 있는 장비로 여러 개의 오리피스로 이루어져 있다. 공기역학렌즈를 지나는 수송 유체와 입자는 이러한 연속 오리피스를 거치면서 팽창과 수축을 반복하며, 관성력의 차이로 인해 입자가 중앙으로 집속된다. 그러나 기존 공기역학렌즈는 고정된 직경의 오리피스를 사용하기 때문에 설계된 공정조건 이외에는 입자의 집속효율이 감소한다는 단점을 지닌다. 따라서 공정조건이 바뀔 경우 공기역학렌즈를 교체해야 되며, 진공이라는 환경하에서 이러한 교체는 많은 시간과 노력을 요구로 한다. 본 연구에서는 이러한 공기역학렌즈의 문제점을 해결하기 위해 다양한 공정조건에서 교체 없이 사용할 수 있는 새로운 형태의 직경 가변형 공기역학렌즈인 조리개형 공기역학렌즈를 제안하였다. 기존 연구를 통해 조리개형 공기 역학 렌즈가 다양한 압력 범위 내에서 나노입자를 성공적으로 집속할 수 있음을 보였지만, 장비를 상용화하기 위해서는 사용자가 좀 더 쉽게 렌즈직경을 결정 할 수 있어야 한다. 이에 본 연구에서는 조리개형 렌즈의 중공 직경에 따른 입자 집속 특성을 평가하였으며, 최종적으로 압력과 집속하고자 하는 직경에 따라 렌즈 중공 직경을 결정할 수 있게 해주는 데이터 베이스를 제작하였다.

• Journal of Wetlands Research
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• v.7 no.2
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• pp.133-144
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• 2005

The study attempts to try a classification of tidal flats types by selecting indicators and go forward to suggest a management plan by tidal flats types. With several indicators selected and PSR(Pressure-State-Response) framework, the relationship between environmental changes and socioeconomic activities in tidal flats was investigated. Tidal flats types were consequently classified into three groups: Wetland Protection Area, Wetland Rehabilitation Area, and Wetland Use-coordination Area. Accordingly, 69 tidal flats were assigned into each groups by PSR analysis: 34 Wetlands Protection Areas, 26 Wetland Rehabilitation Areas, and 9 Wetland Use-coordination Areas. So the baseic management plan of tidal flats must be different by tidal flats and characteristics of region but basically it must give top priority to the sustainable use in the long term.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1462-1468
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• 2014

Xe gas is moved to target from GPM. It is used to feasible nuclear reaction from proton of 30MeV cyclotron being investigated by the Xe-124 gas target system. This system is divided into four parts. The hardware system was constructed by solidworks 3-D CAD and Helium supply is to cool the Havor foil. The Cooling water has the job of cooling down the temperature when Xe gas is being investigated in the target. Temperature and pressure gauges are attached to be checked easily. GPM has the part that prepares to transport Xe gas. There are storage vessel that stores Xe gas, the cold trap that filters humidity and impurity and lastly storage vessel that temporarily stores Xe gas. HCS using the helium is to clean and cool for each part. These parts are configured with SIEMENS PLC and PcVue monitoring program for more comfortable and easy maintenance.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.281-286
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• 2003

Blood Pressure is one of the most fundamental Parameters which reflects physical conditions medically and the blood pressure measurement system using oscillometric method is a Non-Invasive Blood Pressure measurement device by measuring arterial Pressure through a cuff. In this paper. we designed a inflatable wrist blood pressure system which measures blood Pressure during the stepping inflation in the wrist cuff. The hardware system consists of a main power unit, a bladder in cuff unit, signal detection units, signal Processing units. a wireless data transmission unit, and a data display unit. We evaluated the reliability of this system by comparing and analyzing systolic. diastolic blood Pressure, and heart rate with other commercial blood Pressure measurement devices. Characteristic ratio values used to determine systolic and diastolic blood Pressure using MAA(Maximum Amplitude Algorithm) were 0.436 and 0.671 respectively.