• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6346-6352
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• 2013

Radiotherapy of rectal cancer requires a stabilized image but the movement of patients is almost unavoidable in radiotherapy. In this study, the setup error using the radiation treatment technique was compared according to the loading time and BMI(Body Mass Index) for 14 patients with rectal cancer. In addition, the variation of the dose by the average setup error was compared. Therefore, the technique of a selective standard was established. As a result, 3DCRT(3-Dimensional Radiation Therapy) and VMAT(Volumetric Modulated Arc Therapy) showed a similar time and error. In comparison, IMRT(Intensity Modulated Radiation Therapy) increased the time two fold and the error four fold. In BMI, a more pyknic patient showed a larger error for all techniques. Regarding the dose, IMRT and VMAT increased much more than 3DCRT in the average error at the small bowel. Therefore, 3DCRT of the short time will be applied to pyknic rectal cancer. Moreover, VMAT selects than IMRT in the overexposure of the small bowel.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.39-48
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• 2015

In this study, the solar chimney, one of the passive solar systems, is proposed as a method to improve the thermal environment of northern zones in buildings. As this well-known system has rarely been used in building projects, an adequate application of the system is proposed in this paper: the solar chimney system is designed to meet the required ventilation rate and consequently to reduce the ventilation load in the northern part of a building. To investigate such a possibility, a numerical model for the system is developed, and results of numerical tests are used for energy simulations. The results were taken into account for test simulations in EnergyPlus. As a result, approximately 75% of the volumetric ventilation rate required in the north zone could be supplied with the air volume acquired through the system and the monthly mean load was reduced by 29.5%, from 1.584 kWh to 1.117 kWh. The analyses of hourly mean heating and ventilation load over the heating period indicated that the system was very effective at around 13:00. Results show that 33% reduction in the ventilation load and 17% in the heating load for the north zone could be acquired through this system.

• Archives of Craniofacial Surgery
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• v.17 no.3
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• pp.146-153
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• 2016

Background: Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. Methods: This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. Results: All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from $1.0952{\pm}0.0662$ (ranging from 0.9917 to 1.2509) preoperatively to $0.9942{\pm}0.0427$ (ranging from 0.9394 to 1.0680) postoperatively. Conclusion: The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.1
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• pp.76-86
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• 2015

In this study, we presented a method for estimating the potential population damage of the Seoul Nowon-gu area in the event of a terrorist using a vehicle improvised explosive devices (IED). Using the object-based building extraction method with orthophoto image, the area of the apartment has been determined, and the apartment's height and level were estimated based on the elevation data. Using the population estimation method based on total floor area of building, each apartment resident population was estimated, and then potential population damage at the time of terrorist attacks was estimated around the subway station through a scenario analysis. Terrorism damage using IED depends on the type of vehicle greatly because of the amount loadable explosives. Therefore, potential population damage was calculated based on the type of vehicle. In the results, the maximum potential damage population during terrorist attacks has been estimated to occur around Madeul station, Nowon-gu. The method used in this study can be used various population estimation research and disaster damage estimation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.245-250
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• 2006

The effects of aliphatic hydrocarbons (n-hexadecane and n-dodecane) on the volumetric oxygen mass transfer coefficient $(k_L\;a)$ were studied in flat alveolar airlift reactor and continuous stirred tank reactors (CSTRs). In the flat alveolar airlift reactor, high aeration rates (>2vvm) were required in order to obtain efficient organic-aqueous phase dispersion and reliable $k_La$ measurements. Addition of 1% (v/v) n-hexadecane or n-dodecane increased the $k_La$ 1.55- and 1.33-fold, respectively, compared to the control (superficial velocity: $25.8{\times}10^{-3}m/s$, sparger orifice diameter: 0.5 mm). Analysis of the gas-liquid interfacial area a and the liquid film mass transfer coefficient $k_L$ suggests that the observed $k_La$ increase was a function of the media's liquid film mass transfer. Addition of 1% (v/v) n-hexadecane or n-dodecane to analogous setups using CSTRs led to a $k_La$ increase by a factor of 1.68 and 1.36, respectively (superficial velocity: $2.1{\times}10^{-3}m/s$, stirring rate: 250 rpm). These results propose that low-concentration addition of oxygen-vectors to aerobic microbial cultures has additional benefit relative to incubation in purely aqueous media.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.342-348
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• 2001

The present work is to introduce the preliminary experimental results for a primary hydrocyclones process in lake sediment thickening. A few cyclones based on the Rietema standard geometry were prepared. The test particles were sediments from a local lake and waste coal fly ash for a reference test. As a result of the chemical analysis, organic contaminants were abundantly found in smaller particles in overflow. Experimental results showed that the physical characteristics of particles, configuration of the cyclone and operating variables including feed solids concentration and volumetric flow rate could affect the separation efficiency. The limiting feeding velocity for the separation and enrichment of particles was 1.5 m/s, higher separation efficiency, in general, was obtained under the high velocity with the small cyclones.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.904-914
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• 2011

The volumetric errors of CNC machining centers are determined by 21 errors, including 3 linear errors, 6 straightness errors, 3 perpendicular errors, 9 angular errors and non-rigid body errors of the machine tool. It is very time consuming and hard to measure all of these errors in which laser interferometer and other parts are used directly. Hence, as many as 21 separate setups and measurements are needed for the linear, straightness, angular and perpendicular errors. In case of the 5-axis machining centers, two more rotary tables are used. It can make 35 error sources of the movement. Therefore, the measured errors of multi movements of the 5-axis tables are very complicated, even if the relative measured errors are measured. This paper describes the methods, those analyze the error sources of the machining centers. Those are based on shifted diagonal measurements method (SDM), R-test and Double ball bar. In case, the angular errors of machine are small enough comparing with others, twelve errors including three linear position errors, six straightness errors and three perpendicular errors can be calculated by using SDM. To confirm the proposed method, SDM was applied to measuring 3 axes of machine tools and compared with directly measurement of each errors. In addition, the methods for measuring relative errors of multi-axis analysis methods using R-test and Double Ball Bar are introduced in this paper.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1624-1630
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• 2007

This study was designed to investigate the clinical effect of Kamkil-tang on the dyspnea. In this study, we measured the variations of the breathing volume of 20 patients after taking Kamkil-tang. Picrometer is used for the measurement of the volume. The investigation had been performed since from January 1st to August 31th of 2005. The patients for the experiment were mainly composed of patients who had trouble in breathing due to the pneumonectasis, asthmas, pneumonias. The percent of men is 65% in sex distribution and the ratio of persons over 50's was 90%. The results are as follows: After Kamkil-tang was taken to the patients, the enhancement ratio of breathing volume was appeared as 6.6%. The analysis based on an age was that the patients of 50's show the highest volumetric advancement. The ratio of breathing volume was higher as the patients were younger. From this, Kamkil-tang has more efficient on the younger patients. From the relations between the breathing volume before treatment and the enhancement ratio, the increase of the enhancement ratio and the better response to the medicine were shown to the more serious patients. The period of treatment was 22.4 days average. The enhancement ratio of smoker was 25.5, and that of non-smoker was 31.1. At the test of relation between the trouble rate in breathing and the enhancement ratio, Grade I shows the highest enhancement. From the experimental results, It is found that Kamkil-tang gives a noticeable benefit for the patients whose main symptom was breathing problem. Long-term treatments for the serious and younger patients will make much more efficient to the reduction of the symptoms.

• Journal of the Korean Geotechnical Society
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• v.34 no.9
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• pp.19-32
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• 2018

In this study, the applicability and practicality of landslides monitoring by using wireless sensor network (WSN) was analysed. WSN system consists of a sensor node for collecting and transmitting data using IEEE 802.14e standard, a gateway for collecting data and transmitting the data to the monitoring server. In the topology of the sensor network, a highly flexible and reliable mesh type was adopted, and three testbeds were chosen in each location of Seoul metropolitan area. Soil moisture sensors, tensiometers, inclinometers, and a rain gauge were installed at each testbed and sensor node to monitor the landslide. For the estimation of the optimal network topology between sensor nodes, the susceptibility assessment of landslides, forest density and viewshed analysis of terrain were conducted. As a result, the network connection works quite well and measured value of the volumetric water content and matric suction simulates well the general trend of the soil water characteristic curve by the laboratory test. As such, it is noted that WSN system, which is the reliable technique, can be applied to the landslide monitoring.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.