• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.1 s.139
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• pp.79-90
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• 2005

The purpose of this study is to find out the wearing conditions and cause of discomfort with shoes for male college students which will provide useful information fur the shoes manufacturer. The questionnaire survey was conducted on 346 male college students on purchasing practices, wearing conditions, and overall satisfaction with shoes. The results were as follows: Male college students have a tendency to have longer buying cycles and buy more expensive shoes compare to high school students. The order of criteria considered fer purchasing was shape, price, style coordination with clothing. The order of criteria considered for purchasing differed according to their major, economic status and purchasing place. Most of them have two pairs of white or black sports shoes and one pair of either black or brown dress shoes. The most popular material was man made leather but college students have more leather shoes than high school students. There were differences between high school students and college students in wearing conditions, how many they have, material and color. The varieties of shoes differed by season. They were satisfied with their shoes' design and color but unsatisfied with qualify or the material and durability of the shoes. Due to the pressure of the shoes, they experienced discomfort such as numbness, blisters on the feet and red skin. They experienced discomfort on the soles of the feet. The causes of discomfort were shape, width, hight of the heel, material and length in order. Dress shoes cause more discomfort than sport shoes due to the hardness of material, and flexibility of the sole. Since the material differed by the price, the degree of discomfort significantly differed by price too.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.50-55
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• 1996

A numerical simulation on a primary calcinator of porcelain was performed with using Fluent to calculate the heat efficiency by studying velocity vector and temperature profile according to variables such as the location of outlet and porcelain. Control-Volume based Finite Difference Method and Up-wind scheme are used for discretization of differential equation. SIMPLEC Algorithm and standard k-$\varepsilon$ turbulent model are selected to resolve the pressure-velocity coupling and the turbulent. The result of simulation showed that the whole velocity vector field in a calcinator was varied greatly according to the location of outlet. But the whole temperature profile at each zone was still high regardless of the location of outlet because of the radiation. But the temperature of a case with a outlet at sidepart of preheating or cooling zone was little high compared to the case with a outlet on the top of preheating zone. The velocity vector field and temperature profile in a calcinator were almost not affected by the location of porcelain, but the temperature inside a porcelain was much affected according to the place where it was located. The heat efficiency in a calcinator was 44.6% and the gas temperature in the outlet was about 1000 K.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.485-489
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• 2018

For the construction of smart factory that are part of the Fourth Industrial Revolution, data from the production environments and production machines should be collected, analyzed, and feedback should be given to predict when failures take place or parts should be replaced. For this purpose, a system that monitors the production environments and the status of the production machines are required. In this paper, the monitoring system for mobile devices and PC is implemented by collecting environmental data from production sites and sensor data of production machine using LoRa, a low-power wireless communication technology. On the mobile devices, production environments and vibration data can be displayed in real time. In PC monitoring program, sensor data can be displayed graphically to check standard deviation and data variation. The implemented system is used to collect data such as temperature, humidity, and atmospheric pressure of the production environment, and vibration data of production machines.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.4
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• pp.21-28
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• 2000

This study is conducted to analyze effects of soil moisture on the growth of maple(Acer palmatum) under indoor low light intensity. Maples grew under three different light intensities such as sunny place(average 353.2W/$m^2$), half shade(average 7.7 W/$m^2$) and shade/(average 1.9W/$m^2$).Under half shady and shady condition, each 24 planters(2 maples planted in each planter) were used and divided into 3 groups treated with different watering points. Three levels of soil water potential were set for watering points, such as -200mbar, -300mbar or -500mbar. Under sunny condition, there were only group of 8 planters, as comparison. Watering was applied when soil water potentials reached -500maber. The results of plant growth experiment are as followed. 1. Under the shady condition, 32 maples died among 48 maples for 7 months. 9 maples survived, watered at soil water potential -200mbar, 5maples at -300mbar and 2maples at -500mbar. 2. Leaf water content ratios were higher under lower light intensity. For the cell wall became thinner under lower light intensity. 3. Maples in shady were easy to die due to having thin cell wall, therefore they were easy to loss the turgor pressure. 4. In case of half shady condition, the group, watered at soil water potential -200mbar, had much smaller amount of rootlet than -300mbar, because there were excessive soil water. The group, watered at soil water potential -500mbar, had smaller amount of rootlet than -300mbar and there was a remarkable difference in leaf water potential in spite of nearly same soil water potential, because leaves received the water stress under lower soil water potential. 5. When maples grew soundly, the leaf water potential was largely influenced by the soil water potential.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.75-83
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• 2018

In study, Structural stability was considered when applying the high strength strut method with improved general strut method. considered whether there is sufficient stiffness to so as not buckling to the maximum hypothetical earth pressure. also structure stability of the strut component was reviewed. The high strength strut method is a technique used in place of the general strut method. high strength prefabricated Strut method is a technique that has bolt holes drilled in the upper flange at regular intervals. As a result of the buckling analysis, it was considered that the safety factor increased by about 5 %. also Since the stress generated is below the allowable stress, it is judged that structural stability of the strut is ensured. In particular, the safety factor of axial compressive stress increases about 16 % with use of high strength steel when applying the high strength prefabricated strut method. the high strength strut method is construction method may shorten the construction period and there is no expense to purchase additional materials.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.9
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• pp.615-622
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• 2017

A normal shock wave is initially formed in the shock tube that migrates towards the closed end of the tube, which, in turn, leads to the reflection of shock. Due to the interaction of the reflected shock with the boundary layer, bifurcation of the shock wave takes place. A shock train will be generated after the bifurcated shock wave approaches the contact surface. Until now, only a few studies have been conducted to investigate this shock train phenomenon inside the shock tube. For the present study, a CFD analysis has been performed on a two dimensional axisymmetric model of a shock tube using unsteady, compressible Navier-Stokes equations. In order to investigate the detailed characteristics of the shock train phenomenon, quantitative studies have been performed by varying shock tube length, diameter under fixed diaphragm, and pressure ratio inside a shock tube.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1149-1153
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• 1997

Unilateral reexpansion pulmonary edema(RPE) is generally considered a rare complication occurring when a chronically atelectatic lung is rapidly reexpanded by tube thoracostomy or thoracentesis. It can also take place when the lung collapse is of short duration or when the lung is reexpanded without intrapleural sucti n. We experienced a case of RPE following surgical resection in mediastinal thymic cyst A 26 year old female patient suffered from long-standing atelectasis of the right lung due to a huge mediastinal cyst that was misrecognized as tuberculous pleural effusion. Empyema developed after iatrogenic rupture of mediastinal cyst by pig-tailed tube thoracostomy. We successfally managed the ruptured mediastinal thymic cyst, empyema and postoperatively developed RPE following reexpansion of the collapsed lung. The patient was treated with drugs and mechanical ventilation with positive end-expiratory pressure for RPE. The remainder of her hospital course was uneventful.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.367-372
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• 2010

A power plant's heat exchangers work under poor conditions, such as high temperature, high pressure, corrosion, mechanical stress and vibration. Especially, partial joint-weld of heat exchanger's header to stub-tube is the place where incomplete penetration flaws can easily occur. But, it is hard to evaluate the safety of the structure by conventional nondestructive testing techniques. So it is necessary to test integrity of the weld inside and to develop testing technique and equipment that can detect the flaws at the weld point in order to enhance reliability of the test result. In this study, we developed a suitable automated ultrasonic testing system that can inspect the partial joint-weld of header to stub-tube of power plant. Finally, we showed the efficiency of the automated ultrasonic-testing-system from the application.

• Journal of the Korean Society of School Health
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• v.22 no.2
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• pp.169-181
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• 2009

Purpose: Mood disorders such as depression and bipolar disorder are a major mental health problem in college students. We investigate the prevalence of depression and bipolar disorder and the relevance of risk factors for these mood disorders among one college freshmen. Methods: The subjects were 2,865 college students who entered one university located in Seoul and Ansung in 2009. We used BDI (Beck Depression Inventory) for depression assessment and K-MDQ (Mood Disorder Questionnaire) for bipolar disorder assessment. Demographic and socioeconomic factors were measured by questionnaire. Height, weight, blood pressure, total cholesterol, complete blood cell count, and liver function test data were obtained by physical examination for freshmen. Chi-square test and multiple logistic regression were performed to analyze the possible risk factors for depression and bipolar disorder. Results: With different BDI cutoff value, 16 and 21, the prevalence of depression was 8.7% (male: 7.6%, female: 10.1%) and 2.4% (male: 2.5%, female: 2.3%), separately. 'Low economic status', 'urban birth place', and 'low grade at entrance' were significantly associated with depression. Using the original cutoff criterion, defined as clustering of 7 or more symptoms that caused moderate or severe problems, the prevalence of bipolar disorder was 1.3% (male: 1.4%, female: 1.1%). The risk factor of bipolar disorder was academic fields (art fields). Conclusion: Depression and bipolar disorder are common disease in college freshmen. Therefore, Campus-based mental health service program is needed to help with prevention of and early intervention of these mood disorders.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.310-316
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• 2006

In this study, activated carbon in a powder form was used to remove dissolved ammonia which causes a fouling smell in water. Since the adsorption capacity of common powder activated carbon is not high enough, we prepared powder activated carbon deposited on an acid solution to enhance the adsorption capacity. The acid-impregnated activated carbon was applied on the surface of porous fibril support ($10{\sim}50{\mu}m$) by which adsorption and separation processes take place simultaneously by varying effective pressure. As the result, the ammonia removal efficiency is above 60% in the mixing process which is 10~15% higher than general powder activated carbon. From the result of an experiment on the pure permeable test of a dynamic membrane, its transmittance is 400~700 LMH (liter per hour), indicating that the prepared membrane works as a microfiltration membrane. Therefore, it is expected that the membrane prepared in this way would improve the efficiency of water treatment than conventional membranes.