• Journal of the Korean Society for Nondestructive Testing
• /
• v.33 no.5
• /
• pp.443-451
• /
• 2013

Acoustic emission(AE) has emerged as a powerful nondestructive tool to detect any further growth or expansion of preexisting defects or to characterize failure mechanisms. Recently, this kind of technique, that is an in-situ monitoring of inside damages of materials or structures, becomes increasingly popular for monitoring the integrity of large structures like a huge wind turbine blade. In this study, the activities of AE signals generated from external artificial sources was evaluated and located by new developed signal mapping source location method and this test is conducted by 750 kW full-scale blade. And a new source location method was applied to assess the damage in the wind turbine blade during step-by-step static load test. In this static loading test, we have used a full scale blade of 100 kW in capacity. The results show that the acoustic emission activities give a good agreement with the stress distribution and damage location in the blade. Finally, the applicability of the new source location method was confirmed by comparison of the result of source location and experimental damage location.

• Management & Information Systems Review
• /
• v.33 no.3
• /
• pp.1-19
• /
• 2014

Main research question of this study is based on situational gap between donation motivation and behaviour in non-profit organization. However, researches investigating the gap were limited. Therefore, this study examined components of psychological variables. Specially, we proposed the variables about consumer's impulsive motivation or behavior on impulse literature in donation toward non-profit organization. This study conducted a scale development to measure consumer's charity donation impulse based on non-conscious viewpoint. For the development of measurement tool for charity donation impulse, we conducted two stages of research process. First, the measurement items of charity donation impulse were developed through FGI and in-depth interview on experts. Secondly, the factor analysis was performed, and then some items were eliminated through this analysis. As a result, we found the final scale with 26 items, which were named as evaluation sensitivity charity impulse, reward sensitivity charity impulse, functional impulse, non-planning charity impulse. These results showed that the measurement items developed in this study were confirmed to be useful tools for measuring charity donation impulse.

• Journal of Korea Soil Environment Society
• /
• v.1 no.2
• /
• pp.91-101
• /
• 1996

In recent years, phytoremediation, the use of plants to detoxify hydrocarbons, has been a promising new area of research, particularly in situ cleanup of large volumes of slightly contaminated soils. There is increasing need for a mathematical model that can be used as a predictive tool prior to actual field implementation of such a relatively new technique. Although a number of models exist for solute-plant interaction in the vegetated zone of soil, most of them have focused on ionic nutrients and some metals. In this study, we developed a mathematical model for simulation of bioremediation of hydrocarbons in soil, associated with plant root systems. The proposed model includes root interactions with soil-water and hydrocarbons in time and space, as well as advective and dispersive transport in unsaturated soil. The developed model considers gas phase diffusion and liquid-gas mass exchanges. For simulation of temporal and spatial changes in root behavior on soil-water and with hydrocarbons, time-specific distribution of root quantity through soil was incorporated into the simulation model. Hydrocarbon absorption and subsequent uptake into roots with water were simulated with empirical equations. In addition, microbial activity in the rhizosphere, a zone of unique interaction between roots and soil microorganisms, was modeled using a biofilm theory. This mathematical model for understanding and predicting fate and transport of compound in plant-aided remediation will assist effective application of plant-aided remediation to field contamination.

• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.4
• /
• pp.305-310
• /
• 1983

Spatial variability of infiltration rates of 96 samples from Hwadong SiCL was studied by using geostatistical concepts. The measurement was made at the nodes of the regular grid consisting of 12 rows and 8 columns. Sample spacing within rows and columns was 3 and 2 meters, respectively. This study illustrated the use of variogram as a tool to identify the degree of dependency of the infiltration rate on the distance between pairs of measurements and how to take advantage of this dependency. Fractile diagram showed that the distribution of observation was approximately normal. The range of the variogram was about 7.4 meters. The minimum number of samples necessary to reproduce the results similar to the 96 measured values was 8 to 10. Coefficients of theoretical variogram function for computing kriged values and kriged varionces of nuogget effect, slope, and range were 0.444 cm/day, 0.003 cm/day, and 7.4 m, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.8
• /
• pp.977-983
• /
• 2007

Recently, the number of systems which utilize wireless power transmission to a receiving module in a short distance is increasing. For efficient use of receiving space, coils are wound around the ferrite core to produce electromotive force(emf) in suppling power by wireless transmission. This paper analyzed the magnetic flux density distribution in the ferrite core in magnetic field environment which is uniformly oriented along to a single axis at 125kHz. For numerical analysis, Ansoft Maxwell which is applying the FEM(Finite Element Method) method was used. We studied the variations of the gathered magnetic fluxes to the changes of the relative permeabilities of the ferrite cores. Also we calculated the magnetic flux variation by shaving the ferrite core off for the groove of coil winding. Results showed that using a small ferrite core in magnetic field at 100kHz band can increase the amount of magnetic flux $3{\sim}4 times$ than without the core. The magnetic flux decreased 23% by shaving the core 0.5 mm on the periphery of 4.75 mm radius core with the relative permeability 800.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.167-174
• /
• 2001

Reflection method using ultrasonic source has been attempted to obtain the information about tunnel lining structures composed of lining, shotcrete, water barrier and voids at the back of lining. In this work, two different types of sources, i.e. single-pulse source and sweep source, can be used. Single-pulse source with short time duration has the frequency content whose amplitudes tend to be concentrated around the dominant frequency, whereas sweep source with long time duration denotes a flat distribution of relatively larger amplitude over a broad frequency band, although the peak to peak amplitude of single-pulse source wavelet is equivalent to that of sweep source one. In traditional seismic application, a single-pulse source(weight drop, dynamite) is typically used. However, to investigate the fine structure, as it is the case in the tunnel lining structure, the sweep wavelet can be also a desirable source waveform primarily due to the higher energy over a broad frequency band. For the investigation purposes of sweep source, a physical modeling is a useful tool, especially to study problems of wave propagation in the fine layered media. The main purpose of this work was using a physical modeling technique to explore the applicability of sweep source to the delineation of inner layer boundaries. To this end, a two-dimensional physical model analogous to the lining structure was built and a special ultrasonic sweep source was devised. The measurements were carried out in the sweep frequency range 10 ∼ 60 KHz, as peformed in the regular reflection survey(e.g. roll-along technique). The measured data were further rearranged with a proper software (cross-correlation). The resulting seismograms(raw data) showed quitely similar features to those from a single-pulse source, in which high frequency content of reflection events could be considerably emphasized, as expected. The data were further processed by using a regular data processing system "FOCUS" and the results(stack section) were well associated with the known model structure. In this context, it is worthy to note that in view of measuring condition the sweep source would be applied to benefit the penetration of high frequency energy into the media and to enhance the resolution of reflection events.

• Journal of Radiation Protection and Research
• /
• v.32 no.3
• /
• pp.117-122
• /
• 2007

The hydrodynamic behaviors of the clarifier with an interior baffle in a wastewater treatment plant was investigated by using a radiotracer $^{99m}Tc$(30 40 mCi) to verify the results of CFD(computational fluid dynamics) modelling in the previous study. The clarifier model was manufactured with consideration to the hydraulic similarity(1/21) of a real plant($L{\times}W{\times}H:2.6{\times}0.4{\times}0.2m$). By installation of an interior baffle to the clarifier, the strong density current at the bottom of the clarifier decreased substantially and increased the area of sludge settling zone, which were visualized successfully from the radiotracer experiment. Also the portion of short circuit stream changed from 48 % to 32 % and the mean residence time of sludge decreased from 940 sec to 810 sec, which corresponds to the results of CFD modelling. As a result, it is anticipated that radiotracer technology can be used as an important tool for designing new wastewater treatment plants and verifying their performances after structural modifications.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.6 no.2
• /
• pp.233-246
• /
• 2000

The purpose of this study was to investigate the real condition of hospital marketing and concrete strategy on medical consumers need for enhance the effectiveness of hospital management. The data were collected from January 27 to February 3, 2000 at a general hospital located in M city to 205 in-patients and out-patients by questionnaires. The research tool was based on literatures. The data was analysed by the use of percentage, mean, t-test and ANOVA by SAS(Statistical Analysis System) Package Program. The results of this study are summerized as follows: 1. Mean score of the marketing mix (4P 's) was 3.1 in total and each mean score was 3.6 in product, 2.5 in prices, 3.3 in place and 3.1 in promotion. The following are the items which received the highest scores in each: 'The hospital is clean' in service category; 'the prices of meals at the restaurant the patients' families use are reasonable ' in price sphere. In distribution, 'it is easy to locate the hospital' and in promotion,'we'll use this hospital again' and 'we'll recommend this hospital to others'. 2. Marketing mix factors(4P's) was significantly different on the general characteristics in terms of marriage status, occupations and the period of hospitalization. 3. The most important reason for choosing this hospital was 'This is a general hospital with good facilities' and the next were 'The hospital staffs are kind and the hospital is clean' and 'The traffic is convenient to come'. The most important factors contributing to a good image formation of the hospital were 'this is a clean hospital', 'This is a hospital with kind people' and 'this hospital is equipped with good medical facilities'. 4. The factors for making a good image concerning the nursing service were professional knowledge, good nursing skills and kindness. After grasping the marketing conditions of the hospital aided by the above-mentioned research results, the researchers concludes that it is necessary to develop an institutionalized service strategy to increase the satisfaction the patients feel about the hospital facilities and kindness of the staff and as a result, to differentiate it from other medical institutions.

• Journal of Yeungnam Medical Science
• /
• v.11 no.1
• /
• pp.127-134
• /
• 1994

The aim of this study was to identify the usefulness of pelviscopy in treatment besides its diagnostic value. The advantages of pelviscopic surgery are low cost, rapid recovery, good cosmetic effect, low incidence of complication and postoperative adhesion. So most of the pelvic exploration in gynecologic patients are replaced by the pelviscopic surgery these days. Pelviscopic surgery was performed on 136 patients at the Department of Obstetrics and Gynecology, College of Medicine, Yeungnam University from May 1991 to July 1993. The results obtained were as follows : The age distribution of the patients was from 19 to 55 with age of 31.2 years, and the mean parity was 0.96, the most common indication of pelviscopic surgery was tubal pregnancy(66.9%), the second most common indications was ovarian cyst(10.3%) and the other indications were endometriosis, corpus luteum cyst rupture, parovarian cyst, foreign body, tubal ligation, hydrosalpinx, uterine myoma and diagnostic procedure. The main types of surgery were salpingectomy in 58.8% and salpingoophorectomy in 16.3%. The mean duration of hospitalization was 2.1 days without specific complications. According to these results, it was postulated that the pelviscopic surgery was a useful operative tool in gynecologic treatment and its application could be extended to many other areas of gynecology with safety by the development of surgical techniques and instruments.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.10
• /
• pp.1670-1676
• /
• 2018

Objective: This study was conducted to enable on-line prediction of primal and commercial cut weights in Korean slaughter pigs by AutoFom III, which non-invasively scans pig carcasses early after slaughter using ultrasonic sensors. Methods: A total of 162 Landrace, Yorkshire, and Duroc (LYD) pigs and 154 LYD pigs representing the yearly Korean slaughter distribution were included in the calibration and validation dataset, respectively. Partial least squares (PLS) models were developed for prediction of the weight of deboned shoulder blade, shoulder picnic, belly, loin, and ham. In addition, AutoFom III's ability to predict the weight of the commercial cuts of spare rib, jowl, false lean, back rib, diaphragm, and tenderloin was investigated. Each cut was manually prepared by local butchers and then recorded. Results: The cross-validated prediction accuracy ($R^2cv$) of the calibration models for deboned shoulder blade, shoulder picnic, loin, belly, and ham ranged from 0.77 to 0.86. The $R^2cv$ for tenderloin, spare rib, diaphragm, false lean, jowl, and back rib ranged from 0.34 to 0.62. Because the $R^2cv$ of the latter commercial cuts were less than 0.65, AutoFom III was less accurate for the prediction of those cuts. The root mean squares error of cross validation calibration (RMSECV) model was comparable to the root mean squares error of prediction (RMSEP), although the RMSECV was numerically higher than RMSEP for the deboned shoulder blade and belly. Conclusion: AutoFom III predicts the weight of deboned shoulder blade, shoulder picnic, loin, belly, and ham with high accuracy, and is a suitable process analytical tool for sorting pork primals in Korea. However, AutoFom III's prediction of smaller commercial Korean cuts is less accurate, which may be attributed to the lack of anatomical reference points and the lack of a good correlation between the scanned area of the carcass and those traits.