In this study, pressure drop was measured in the pulse jet bag filter without venturi on which 16 numbers of filter bags (Ø140 × 850 ℓ) are installed according to operation condition(filtration velocity, inlet dust concentration, pulse pressure, and pulse interval) using coke dust from steel mill. The obtained 180 pressure drop test data were used to predict pressure drop with multiple regression model so that pressure drop data can be used for effective operation condition and as basic data for economical design. The prediction results showed that when filtration velocity was increased by 1%, pressure drop was increased by 2.2% which indicated that filtration velocity among operation condition was attributed on the pressure drop the most. Pressure was dropped by 1.53% when pulse pressure was increased by 1% which also confirmed that pulse pressure was the major factor affecting on the pressure drop next to filtration velocity. Meanwhile, pressure drops were found increased by 0.3% and 0.37%, respectively when inlet dust concentration and pulse interval were increased by 1% implying that the effects of inlet dust concentration and pulse interval were less as compared with those changes of filtration velocity and pulse pressure. Therefore, the larger effect on the pressure drop the pulse jet bag filter was found in the order of filtration velocity(Vf), pulse pressure(Pp), inlet dust concentration(Ci), pulse interval(Pi). Also, the prediction result of filtration velocity, inlet dust concentration, pulse pressure, and pulse interval which showed the largest effect on the pressure drop indicated that stable operation can be executed with filtration velocity less than 1.5 m/min and inlet dust concentration less than 4 g/m3. However, it was regarded that pulse pressure and pulse interval need to be adjusted when inlet dust concentration is higher than 4 g/m3. When filtration velocity and pulse pressure were examined, operation was possible regardless of changes in pulse pressure if filtration velocity was at 1.5 m/min. If filtration velocity was increased to 2 m/min. operation would be possible only when pulse pressure was set at higher than 5.8 kgf/cm2. Also, the prediction result of pressure drop with filtration velocity and pulse interval showed that operation with pulse interval less than 50 sec. should be carried out under filtration velocity at 1.5 m/min. While, pulse interval should be set at lower than 11 sec. if filtration velocity was set at 2 m/min. Under the conditions of filtration velocity lower than 1 m/min and high pulse pressure higher than 7 kgf/cm2, though pressure drop would be less, in this case, economic feasibility would be low due to increased in installation and operation cost since scale of dust collection equipment becomes larger and life of filtration bag becomes shortened due to high pulse pressure.

In this study, analyzed of the correlation UPVand the compressive strength of structural timber. As a result, increased of UPV in accordance with the compressive strength increases. Though more experiments, judgment to be possible to estimate the compressive strength of the structural timber with UPV

By using non-destructive inspection equipment, ultrasonic and schmidt hammer, this research performed non-destructive inspection of underwater concrete for more efficient management in underwater concrete structures. And based on instrumented rebound hardness and ultrasonic pulse velocity, we developed the underwater concrete structures-strength estimation models using artificial neural network.

본 논문은 기존 수중 콘크리트 구조물의 강도관리 및 진단기술의 중요성은 날로 증가함에 따라 개발되고 있는 ROV (Remote Control Vehicle)에 탑재될 수 있는 비파괴 검사 장비를 개발하여 콘크리트 내부의 강도측정을 하고자하였다. 수중화된 슈미트해머와 초음파센서를 통하여 수중에 있는 콘크리트 공시체의 반발경도 및 초음파속도를 계측하여 실제 압축강도 값과 비교하였으며 이를 통하여 수중에서의 강도추정식을 도출하였다. 도출된 3가지 식 중에서 반발경도와 초음파속도를 복합적으로 사용하는 복합식이 가장 정확도가 높았으며 이에 따라 실제 수중에서의 콘크리트의 강도를 추정하고자 할 때 활용 가능성도 높아질 것으로 예상된다.

Among Non-destructive tests Ultrasonic Pulse Velocity Method is identified as an efficient and simple method to estimate the mechanical characteristics of the material. In this study, Ultrasonic Pulse Velocity Method for Normal concrete were applied to geopolymer concrete specimens. Pressure waves, ultrasonic velocity and maximum frequency in these specimens were measured. similar to normal concrete, Initial ultrasonic velocity of geopolymer concretes reflected stress of geopolymer concretes, but maximum frequency bandwidth did not.

This study investigated the compressive strength of concrete by using ultrasonic pulse velocity method, and proposed the equation able to predict the compressive strength of concrete.

In case of measuring strength of concrete using ultrasonic pulse testing, setting reasonable range of limitations to get reliable strength data results is highly recommended. To resolve this issue, ultrasonic testings were performed on several concrete specimens ,randomly selected and contain strength ranged from 20 to 200MPa, to measure values of ultra sonic velocity and actual strength. Then advanced data analyses were performed based on the results from the experimental works.

Ultrasonic pulse velocity method is widely used to evaluate the internal condition of concrete without loss of the structural integrity. In this study, the specimens were made for the varying the lightweight fine aggregates replacement rate of 0, 50, 100%. These specimens were used to measure the ultrasonic velocity and maximum frequency were analyzed. As Lightweight fine aggregates substitution rate was increased, the ultrasonic velocity and the maximum frequency bandwidth were also increased

In this study, various difference sizes of lightweight fine aggregates were used to make concrete specimens. The pressure waves, ultrasonic velocity and maximum frequency were measured for the specimens. Initial ultrasonic velocities were influenced by the sizes of lightweight fine aggregates, but not by the maximum frequency bandwidth.

In this study, one of nondestructive evaluation (NDE)　techniques for the effective maintenance of underwater concrete structures are investigated: Ultrasonic Pulse Velocity Method and Rebound hardness Test. Currently, lots of ROV(Romotely Operated Vehicle) Systems to inspection Underwater Concrete Structures are being considered.

In this study, I tried to derive the expression intensity estimation through analyzing the correlation between wave velocity and compressive strength of high-strength concrete and normal-strength one, using ultrasonic pulse velocity which is one of the non-destructive tests which do not damage the structure. By producing a material age strength and body separate experiment which is applied to the ultrasonic pulse velocity, we have derived the estimating compressive strength such as a formula strength of normal-strength concrete : Fc=0.0841vp3.6018, R2=0.82 high strength concrete : Fc=0.0008vp6.9287, R2=0.88. As a result of this verification experiment, the estimated error rate of the compressive strength of normal strength concrete is 16.32%, in the case of high-strength concrete is now 7.58 percent.

본 연구는 다양한 식물들이 가지는 비침투적 치유 요소 중 감각자극 요인에 대한 인간의 심리, 생리적 반응을 밝히는 연구의 일환으로 수행되었으며, 본 연구에서는 허브식물 Lavandula spp., Mentha spicata, Thymus praecox 3종의 시각, 후각, 촉각의 세가지 감각자극 요소에 대한 맥박수를 분석하는 것을 목적으로 수행되었다. 식물을 구별하지 않고 자극별로만 맥박수의 차이를 분석해 본 결과, 후각과 촉각자극에서 맥박수가 유의하게 증가하였고, 자극별로 살펴본 식물간의 맥박수는, 모니터에 사진으로 제공된 시각적 이미지에서는 유의한 차이가 나타나지 않았고, 후각과 촉각자극에서 Lavandula spp.의 경우가 다른 식물에 비해 맥박이 통계적으로 유의하게 높은 것으로 나타났다. 식물별로 살펴본 자극간의 맥박수 차이는 Lavandula spp.와 Thymus praecox에서는 차이가 나타나지 않았으나 Mentha spicata에서는 후각과 촉각자극 시에 시각자극보다 맥박이 통계적으로 유의하게 높은 것으로 나타났다.

The dual channel Pierce-Blitzstein photometer (PBPHOT) was productively used at the Flower and Cook Observatory to provide 60 years of study of binary systems and other cosmic objects. We review the history of this instrument, discuss its calibration, and recall some personal and professional interactions with Professor Robert H. Koch.

A pilot-scale pulse-jet bagfilter was designed, built and tested for the effects of four operating conditions (filtration velocity, inlet dust concentration, pulse pressure, and pulse interval time) on the total system pressure drop, using coke dust from a steel mill factory. Two models were used to predict the total pressure drop according to the operating conditions. These model parameters were estimated from the 180 experimental data points. The empirical model (EM) with filtration velocity, areal density, inlet dust concentration, pulse interval time and pulse pressure shows the best correlation coefficient (R=0.971) between experimental data and model predictions. The empirical model was used as it showed higher correlation coefficient (R=0.971) compared to that of the Multivariate linear regression(MLR) (R=0.961). The minimum pulse pressure predicted by empirical model (EM) was 5kg/㎠.

본 연구에서는 국내 기술로 개수로 흐름 측정에 활용할 수 있는 초음파 유속 프로파일러를 개발하였다. 이 유속 프로파일러는 초음파의 도플러 효과로 유속을 측정하는 원리에 기반을 두고 있으며, 도플러 주파수는 펄스반복주파수(Pulse Repetition Frequency) 기법에 의해 산정된다. 개발된 유속 프로파일러의 성능을 검증하기 위해 실내 실험 및 현장 테스트를 수행하였다. 실험 결과 개발된 유속 프로파일러는 바닥에서부터 약 0.1 cm 이상의 수심

직접적인 매개변수 추정방법의 다양한 Neyman-Scott 구형펄스모형(NSRPM) 기반 모형에 대한 적용성 검토와 정규분포를 이용한 새로운 NSRPM(NMNSRPM)의 개발 연구를 수행하였다. 기상청 서울 유인관측소에서 제공하는 49년의 관측 강수자료를 사용하여 매개변수를 추정하였으며, 추정된 매개변수들의 정확도를 판단하고자 생성된 강수자료의 통계값, 유강수일 비율, 강수분포를 비교하였다. 통계값을 비교해본 결과 NSRPM과 수정 NSRPM(MNSRP

The new empirical static model was constructed on the basis of dimension analysis to predict the pressure drop according to the operating conditions. The empirical static model consists of the initial pressure drop term (N dust = ω0υf / P pulse t) and the dust mass number term (Δp initial), and two parameters (dust deposit resistance and exponent of dust mass number) have been estimated from experimental data. The optimum injection distance was identified in the 64 experimental data at the fixed filtration velocity and pulse pressure. The dust deposit resistance (K d), one of the empirical static model parameters got the minimum value at , d=0.11m, at which the total pressure drop was minimized. The exponent of dust mass number was interpreted as the elasticity of pressure drop to the dust mass number. The elasticity of the unimodal behavior had also a maximum value at , d=0.11m, at which the pressure drop increased most rapidly with the dust mass number. Additionally, the correlation coefficient for the new empirical static model was 0.914.

The pressure drop through pulse air jet-type bag filter is one of the most important factors on the operating cost of bagfilter houses. In this study, the pilot-scale pulse air jet-type bag filter with about 6 ㎡ filtration area was designed and tested for investigating the effects of the four operating conditions on the total pressure drop, using the coke dust collected from a steel mill factory. When the face velocity is higher than 2 m/min, it is not applicable to on-spot due to the increase of power expenses resulting from a high-pressure drop, and thus, 1.5 m/min is considered to be reasonable. The regression analysis results show that the degree of effects of independent parameters is a order of face velocity > concentration > time > pressure. The results of SPSS answer tree analysis also reveal that the operation time affects the pressure drop greatly in case of 1 m/min of face velocity, while the inlet concentration affects the pressure drop in case of face velocity more than 1.5 m/min.

SRPM (Neyman-Scott Rectangular Pulse Model)은 수문학분야에서 널리 쓰이고 있는 강수생성모형이다. NSRPM을 구축하기 위해서는 총 5개의 매개변수를 추정하여야 한다. 일반적으로 사용되는 모멘트를 이용하여 매개변수를 추정할 경우, 사용되는 목적함수의 증가에 따라 추정되는 매개변수의 결과가 평탄해지고 목적함수를 추가하거나 조정하기 위해서는 복잡한 수식을 다시 계산해야 하며 추정된 매개변수가 무작위변수 생성 모형에 따라 상이

본 연구는 원예치료프로그램이 정신분열병 환자의 혈압, 맥박 및 정서안정에 미치는 영향에 대하여 알아보고자 실시하였다. 대구광역시 남구 대명동에 위치한 남구정신보건센터를 이용하고 있는 정신분열병 남녀 7명을 대상으로 2002년 7월 9일부터 2002년 10월 1일까지 3개월간 주1회 총 12회 원예치료프로그램을 실시하였다. 매 프로그램 실시 전․후에 혈압, 맥박을 측정한 결과 수축기혈압의 경우 원예치료 실시 전 91.5에서 실시 후 87.04로 낮아졌으며 0.10수준의 차이가 있었다. 확장기혈압의 경우 원예치료 실시 전 69.49에서 실시 후 65.27로 4.22로 낮아졌으며 0.05수준의 차이가 있었다. 맥박의 경우도 혈압과 마찬가지로 원예치료 실시 전 81.79에서 실시 후 78.72로 3.07 낮아졌으며 0.10수준으로 차이가 있었다. 간이정신진단검사 결과 신체화의 경우 원예치료 실시 전 51.55에서 실시 후 42.18로 9.37 낮아졌으며 0.10수준으로 개선되었다. 원예치료평가표(KHY)의 경우 정서적 발달, 사회적 발달 모든 항목에서 0.05 수준의 유의한 차이가 있었다. 특히 정서적 발달에서는 활동의욕, 충동억제, 집중력, 자주성, 성취감, 작업태도에서 높게 나타났으며, 사회적 발달에서는 도덕성과 협조성, 참여도에서 높게 나타났다. 이상의 결과로부터 원예치료가 혈압, 맥박 및 정서적 안정에 영향을 미치는 것으로 나타났다. 향후 대상 자에게 적합한 프로그램으로 체계적이고 지속적인 원예치료를 적용한다면 정신분열병 환자의 증상감소 및 정서적 안정은 물론 사회적 기능면에서도 크게 향상될 것이라 기대한다.