• Journal of the Korean Society of Radiology
• /
• v.16 no.7
• /
• pp.975-984
• /
• 2022

Since a linear transducer has an area of interest equal to the length of the transducer, the area of interest can be expanded using the virtual convex function installed in the device.However, it was thought that the change in the direction of the ultrasonic sound velocity according to the change in the visual area of interest would affect the image quality, so this was objectively confirmed. For this study, image evaluation and SNR·CNR of the phantom for ultrasound quality control were measured. As a result, in the phantom image evaluation, both images were able to identify structures in functional resolution, grayscale, and dynamic range. However, it was confirmed that the standard image was excellent in the reproducibility of the size and shape of the structure. As a result of SNR·CNR evaluation, SNR·CNR of most trapezoidal images was low, except for structures at specific locations. In addition, through the statistical analysis graph, it was further confirmed that the SNR and CNR for each depth decreased as the size of the cystic structure decreased. Through this study, it was confirmed that the use of the function has the advantage of providing a wide visual area of interest, but it has an effect on the image quality. Therefore, when using the virtual convex function, it is judged that the examiner should use it in an appropriate situation and conduct various studies to acquire high-quality images and to improve the understanding and proficiency of the equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.288-290
• /
• 2022

As part of the SOC digitization for smart water management and flood prevention, the government reported that automatic and remote control system for drainage facilities (180 billion won) to 57% of national rivers and established a real-time monitoring system (30 billion won). In addition, they were also planning to establish a smart dam safety management system (15 billion won) based on big data at 11 regions. Therefore, research is needed for smart water management and flood prevention system that can accurately calculate the flow rate through real-time flow rate measurement of rivers. In particular, the most important thing to improve the system implementation and accuracy is to ensure the accuracy of real-time flow rate measurements. To this end, radar sensors for measuring the flow rate of electromagnetic waves in the United States and Europe have been introduced and applied to the system in Korea, but demand for improvement of the system continues due to high price range and performance. Consequently, we would like to propose an improved flow rate measurement and flood forecast system by developing a radar sensor for measuring the electromagnetic surface current meter for real-time flow rate measurement.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.6B
• /
• pp.697-707
• /
• 2008

The grid-based KIneMatic wave STOrm Runoff Model (KIMSTORM) by Kim (1998) predicts the temporal variation and spatial distribution of overland flow, subsurface flow and stream flow in a watershed. The model programmed with C++ language on Unix operating system adopts single flowpath algorithm for water balance simulation of flow at each grid element. In this study, we attempted to improve the model by converting the code into FORTRAN 90 on MS Windows operating system and named as ModKIMSTORM. The improved functions are the addition of GAML (Green-Ampt & Mein-Larson) infiltration model, control of paddy runoff rate by flow depth and Manning's roughness coefficient, addition of baseflow layer, treatment of both spatial and point rainfall data, development of the pre- and post-processor, and development of automatic model evaluation function using five evaluation criteria (Pearson's coefficient of determination, Nash and Sutcliffe model efficiency, the deviation of runoff volume, relative error of the peak runoff rate, and absolute error of the time to peak runoff). The modified model adopts Shell Sort algorithm to enhance the computational performance. Input data formats are accepted as raster and MS Excel, and model outputs viz. soil moisture, discharge, flow depth and velocity are generated as BSQ, ASCII grid, binary grid and raster formats.

• Atmosphere
• /
• v.34 no.3
• /
• pp.305-317
• /
• 2024

The study examines the effects of parameters that define the characteristics of raindrops on the simulated precipitation during the summer season over Korea using the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) cloud microphysics scheme. Prescribed parameters, defining the characteristics of hydrometeors in the WDM6 scheme such as a_R, b_R, and f_R in the fall velocity (V_R) - diameter (D_R) relationship and shape parameter (𝜇_R) in the number concentration (N_R) - D_R relationship, presents different values compared to the observed data from Two-Dimensional Video Disdrometer (2DVD) at Boseong standard meteorological observatory during 2018~2019. Three experiments were designed for the heavy rainfall event on August 8, 2022 using WRF version 4.3. These include the control (CNTL) experiment with original parameters in the WDM6 scheme; the MUR experiment, adopting the 50th percentile observation value for 𝜇_R; and the MEDI experiment, which uses the same 𝜇_R as MUR, but also includes fitted values for a_R, b_R, and f_R from the 50th percentile of the observed V_R - D_R relationship. Both sensitivity experiments show improved precipitation simulation compared to the CNTL by reducing the bias and increasing the probability of detection and equitable threat scores. In these experiments, the raindrop mixing ratio increases and its number concentration decreases in the lower atmosphere. The microphysics budget analysis shows that the increase in the rain mixing ratio is due to enhanced source processes such as graupel melting, vapor condensation, and accretion between cloud water and rain. Our study also emphasizes that applying the solely observed 𝜇_R produces more positive impact in the precipitation simulation.

• Journal of Korean Society of Transportation
• /
• v.19 no.4
• /
• pp.35-47
• /
• 2001

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence. numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristic of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends are towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a methodology of motor vehicle emission calculation by using real-time traffic data was studied. A methodology for estimating emissions of CO at a test area in Seoul. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It was calculated speed-related mass of CO emission from traffic tail pipe of data from traffic system, and parameters are considered, volume, composition, average velocity, link length. And, the result was compared with that of a method of emission calculation by VKT(Vehicle Kilometer Travelled) of vehicles of category.

• Journal of Bio-Environment Control
• /
• v.8 no.2
• /
• pp.75-82
• /
• 1999

This study was carried out to examine the effect of day/nignt temperatures during seedling culture on the vegetative and reproductive growth of Lycopersicum esculentum ‘Seokwang’. The study was consisted of two culture stages, plug seedling production in the growth chamber and hydroponic culture of the plant in a glasshouse. Experiments were replicated over time. The germinated seedlings were raised for 33 days (experiment 1) and 35 days (experiment 2) in 4 growth chambers, each with day/night temperatures of either $25^{\circ}C$/$25^{\circ}C$, 16$^{\circ}C$/16$^{\circ}C$, 16$^{\circ}C$/$25^{\circ}C$ or $25^{\circ}C$/16$^{\circ}C$. Cool-white fluorescent lamps provided 140$\mu$mol.m$^{-2}$ .s$^{-1}$ light for 12h each day. In the second experiment, all chambers were supplied with 1000$\mu$mol.mol$^{-1}$ CO$_{2}$ during the photoperiod and had an air velocity of 0.3m.s$^{-1}$ and relative humidity of 80%. Plug seedlings raised were transplanted to rockwool slabs in a glasshouse and were grown hydroponically using the same nutrient solutions used for seedling culture for 37 days (experiment 1) and 35 days (experiment 2). Plant height was affected more by mean daily temperature than by interaction of day and night temperatures. Plant height was the highest in 16/16$^{\circ}C$ treatment. Leaf count was not affected by day and night temperatures, and the chlorophyll concentration was the highest in 16/$25^{\circ}C$ treatment. Fresh and dry weights of stem tended to be greater in treatments of constant day and night temperature. The number of node on which first and second flower clusters were set was significantly higher in 25/$25^{\circ}C$ treatment than in the other treatments. Days to flower of the first flower on the first flower cluster were the greatest in 25/$25^{\circ}C$ and the least in 16/$25^{\circ}C$ treatment. Vegetative and reproductive growth, such as height, fresh and dry weights, days to flower, and nodes of the 1st and 2nd flower cluster set were affected by day/night temperatures.

• Clinics in Shoulder and Elbow
• /
• v.15 no.2
• /
• pp.79-85
• /
• 2012

Objective: It has been expected that patient with posttraumatic recurrent anterior shoulder dislocation might have limited daily life activity because of pain and apprehension of dislocation. But there have been only a small number of investigations regarding the rotator strength in this patient. The aim of this study is to find the characteristics about rotator strength of patient with posttraumatic recurrent anterior shoulder dislocation using an isokinetic testing. Method: We enrolled thirteen patients with posttraumatic recurrent anterior shoulder dislocation and fifteen sex, age-matched healthy nonathletic subjects in this controlled study. All participants were male and there were no significant differences between the two groups in age, height, weight, BMI. Isokinetic internal rotator and external rotator strength was evaluated with a Biodex Isokinetic Testing machine (Biodex Medical Systems, Shirley, NY, USA), tests were performed at 60 deg/sec and 180 deg/sec for both sides. Peak torque normalized to body weight, external rotator to internal rotator ratio, total work and fatigue were calculated for each angular velocity. The association between internal rotator and external rotator strength and shoulder instability was analyzed by comparisons with a control group. Results: Any notable differences could not be found between the two groups given all data from no symptomatic left shoulder. There were no significant differences between the two groups statistically in internal rotation strength of right shoulder. However, there has been a tendency that at all angular velocities, external rotator peak torque to body weight, total work and external rotator to internal rotator ratio were significantly lower in the anterior instability group than the control group at all angular velocities. There was no substantial difference between those groups with respect to the fatigue of external rotator and internal rotator in our study. Conclusion: The prominent characteristics of posttraumatic recurrent anterior shoulder dislocation are external rotator weakness and loss of balance with external rotator and internal rotator. Therefore selective training using this information rotator might be helpful in conservative treatment and rehabilitation.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.4
• /
• pp.769-777
• /
• 2020

The purpose of this study was to investigate the effects of 8 weeks Self-Myofascial Release exercise on body composition, vascular and metabolic functions in obese female college students. The subjects were 19 obese female college students (n = 9) who were randomly assigned to an exercise group(n=9) and control group(n=9), with an exception of except 1 abandonment. The Self-Myofascial Release exercise group performed exercises twice a week for 8 weeks and for 40 minutes at one time using a foam roller, and the control group maintained normal life pattern for the same period. Body composition was measured by body weight, body fat percentage, vascular function was measured by pulse wave velocity(PWV), augmentation index(AIx), brachial artery vascular flow-mediated dilation(FMD), and metabolic function was measured by fasting glucose and triglyceride levels. The Self-Myofascial Release exercise with foam roller showed no significant effect on body weight and body fat percentage. The Self-Myofascial Release exercise with foam roller showed no significant effect on heart rate, FMD, PWV but, SBP, CSBP and AIx were significant decreased. The Self-Myofascial Release exercise with foam roller showed no significant effect on fasting glucose and triglyceride levels. In conclusion, 8-week Self-Myofascial Release exercise for obese female college students showed no significant effect on body composition and metabolic function, but improved SBP, CSBP and AIx levels significantly. Therefore, Self-Myofascial Release exercise will be an effective way to improve the vascular function of obese female college students.

• Journal of Bio-Environment Control
• /
• v.23 no.4
• /
• pp.293-302
• /
• 2014

This study was carried out to develop rain shelter which can make an appropriate size and environment for Chinese cabbage rainproof cultivation. Fifty three farms with chinese cabbage rainproof cultivation system have been investigated to set up width and height of rain shelter. Mostly the width of 6m was desired for rain shelter and the height of 1.6m for their eaves, so these values were chosen as the dimensions for rain shelter. After an analysis of their structural safety and installation costs by the specifications of the rafter pipe, Ø$25.4{\times}1.5t$ and 90cm have been set as the size of rafter that such size costs the least. This size is stable with $27m{\cdot}s^{-1}$ of wind velocity and 17cm of snow depth. Therefore it is difficult to apply this dimension to area with higher climate load. In order to sort out such problem, the rain shelter has been designed to avoid damage on frame by opening plastic film to the ridge. Once greenhouse band is loosen by turning the manual switch at the both sides of rain shelter and open button of controller is pushed then switch motor rises up along the guide pipe and plastic film is opened to the ridge. Chinese cabbage can be damaged by insects if rain shelter is opened completely as revealed a field. To prevent this, farmers can install an insect-proof net. Further, the greenhouse can be damaged by typhoon while growing Chinese cabbage therefore the effect of an insect-proof net on structural safety has been analyzed. And then structural safety has been analyzed through using flow-structure interaction method at the wind condition of $40m{\cdot}s^{-1}$. And it assumed that wind applied perpendicular to side of the rain shelter which was covered by insect-proof net. The results indicated that plastic film was directly affected by wind therefore high pressure occurred on the surface. But wind load on insect-proof net was smaller than on plastic film and pressure distribution was also uniform. The results of structural analysis by applying pressure data extracted from flow analysis indicated that the maximum stress occurred at the end of pipe which is the ground part and the value has been 54.6MPa. The allowable stress of pipe in the standard of structural safety must be 215 MPa or more therefore structural safety of this rain shelter is satisfied.

• Korean Journal of Agricultural Science
• /
• v.6 no.1
• /
• pp.56-64
• /
• 1979

Two types of fiat-plate collector were designed and constructed for utilizing the solar energy as heating source of red pepper drying. It was performed to investigate the basic factors on using the collectors and the drying effect on various types of red pepper, and the results obtained are summarized as follows. 1. The optimum tilted angles of the collector in Daejeon area were ${\phi}-15^{\circ}$ in summer season and ${\phi}+15^{\circ}$ in winter season when it was adjusted two times per a year: 2. In the conditions during experiment period, average atmospheric temperature and relative humidity were $25.6^{\circ}C$ and 52.6%, respectively, and $42.0^{\circ}C$, 74.2% in the control chamber. The temperature in the drying chamber connected to the water heater was the highest but relative humidity in the chamber connected to the air heater was the lowest among the chambers. 3. The drying velocity of whole red pepper in the chamber connected to the water heater was the fastest as 2.3 times as compared to the whole type on the mat drying followed by air heater and control in decreasing order. The horizontally cut red pepper in the chamber connected to the water heater was dried exceedingly fast among twelve plots. 4. The content of capsaicine as pungent principle and of capsanthine as red pigment in the red pepper were reduced during drying but there were no differences significantly on the drying method, and it could not affect much on the quality of dried product.