• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.596-602
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• 2020

Blending process of adhesive production has a cooling process to cool down the temperature of the solution which was heated up to 76 ℃ with a mineral insulated (MI) cable by 30 ℃ at room temperature. Using a MI cable in the adhesive production process makes the production inefficient because it takes about 10 h for the cooling process. If a jacketed vessel is used instead of the MI cable, it would shorten the cooling downtime without any additional cooling system by using cold water. However, there are various types of jacketed vessels, and thus the most suitable type should be found before set up. In this study, we designed the optimized jacketed vessel for the adhesive production process by calculating the cooling downtime, which impacts production efficiency, as a function of the jacket types using computational fluid dynamics. As a result, the cooling performance of the plain jacket was 32.7% superior to that of the half-pipe coil jacket with the same height. In addition, the plain jacket with 60% spiral baffle reduced the cooling downtime and operating time by 80.4% and 25.1%, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.359-366
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• 2022

In this study, the load fluctuation of the main engine is considered to be a disturbance for the jacket coolant temperature control system of the low-speed two-stroke main diesel engine on the ships. A nonlinear PID temperature control system with satisfactory disturbance rejection performance was designed by rapidly transmitting the load change value to the controller for following the reference set value. The feed-forwarded load fluctuation is considered the set points of the dual loop control system to be changed. Real-coded genetic algorithms were used as an optimization tool to tune the gains for the nonlinear PID controller. ITAE was used as an evaluation function for optimization. For the evaluation function, the engine jacket coolant outlet temperature was considered. As a result of simulating the proposed cascade nonlinear PID control system, it was confirmed that the disturbance caused by the load fluctuation was eliminated with satisfactory performance and that the changed set value was followed.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.33-40
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• 1997

Recently, there are an increasing needs for high speed rotating spindle which is an important mechanical ele- ment for a high efficiency machine tool in order to shorten machining time and cut production costs. The heat gen- eration is the most important problem in the motor integrated spindle. In this study, the effects of temperature distribution and thermal behavior according to the oil-air lubrication and cooling conditions are investigate theo- retically and experimentally on the motor-integrated spindle under unloading condition. The experimental spin- dle system is composed with the angular contact steel ball bearings, oil-air lubrication, air or oil jacket cooling system. To analyze the thermal behavior and cooling characteristics for the motor integrated spindle, the analysis using the finite element method is carried out. The analytical results are compared with the experimental results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.691-696
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• 2000

Cooling characteristics of cooling jacket for spindle system with built-in motor are studied. Three dimensional model was selected for the analysis of the helical-type cooling jacket. This model includes the estimation on the amount of heat generation from bearing and built-in motor and the thermal characteristic values such as heat flux on the boundary. The temperature distributions are analyzed and the cooling by Nusselt number and total heat transfer coefficient. Numerical results show that stream-wise cross section area and flow rate are important factors for cooling characteristics of cooling jacket.

• Fashion & Textile Research Journal
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• v.22 no.6
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• pp.844-852
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• 2020

This study is to understand the preferences of pilots, flight engineers and crew who work in the same aircraft but are exposed to different working environments and perform different mission operations in order to develop an ergonomic flight jacket. Based on a preliminary investigation, a survey of 107 pilots and 36 flight engineers and crew was conducted. The results are as follows; Pilots can control the temperature inside the cockpit, so they are less exposed to the cold when working, while flight engineers and crew are exposed to the cold more because they have many external tasks. The reason for the problem of the current flight jacket was a difference in ranking between two groups, but the highest ranking was poor dimensional suitability due to the habit of wearing layers of clothing. As a result of preferred design, there were significant differences between groups in the item of overall style. Pilots preferred a bomber jacket style(P:68.2%, E&C:44.4%), on the other hand, flight engineers and crew preferred a field jacket style(P:26.2%, E&C:55.6%)(p<.01). They preferred a stand collar(P:71.0%, E&C:86.1%), a fastener slider for a front fastening(P:62.6%, E&C:61.1%), fastener tape cuffs(P:54.2%, E&C:47.2%), a jacket with a softshell(P:86.9%, E&C:83.3%), fleece as softshell material(P:88.8%, E&C:69.4%), and fastener sliders as a attaching method(P:69.2%, E&C:61.1%). A hem fastening will be selected differently according to the overall style of outshell. Additionally, they preferred more than 5ea pockets(P:51.4%, E&C:44.4%), fastener sliders as pocket's fastenings(P:48.6%, E&C:61.1%), armpit ventilations(P:62.9%, E&C:58.5%). The results of above will be considered to design an ergonomic flight jacket.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.1-10
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• 1998

In this paper, we investigated the improvement of characteristics of knock, emission and fuel consumption rate by optimizing the location and size of water transfer holes in cylinder head gasket without change of engine water jacket design itself. The cooling system was modified in the direction of reducing the metal temperature in the head and increasing the metal temperature in the block. The optimization of water transfer holes in cylinder head gasket was obtained by "flow visualization test". The water transfer holes were concentrated in front side of the engine in order to reduce thermal boundary layer in the water jacket of No. 2 and No. 3 combustion changer in the cylinder head, which would have a large knock intensity, and increase thermal boundary layer in the water jacket of the cylinder block. When the modified coolant flow pattern was applied as proposed in this paper, the knock characteristic was improved. The spark timing was advanced up to 2$^{\circ}$ in low and middle speed range at a full load. In addition, HC emission at MBT was reduced by 5.2%, and the fuel consumption rate was decreased up to 1% in the driving condition of 2400 rpm and 250 KPa. However, since this coolant flow pattern mentioned in this paper might deteriorate the performance of vehicle cooling system due to the coolant flow rate reduction, a properly optimized point should be obtained. obtained.

• Journal of Fashion Business
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• v.24 no.5
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• pp.140-157
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• 2020

The purpose of this study is to develop three functions for smartphones and PCs using a textile touch sensor in an everyday sports jacket and to present their usefulness; to this end, we have developed a mutual capacitive textile touch sensor and corresponding structure, and we have implemented three functions into a textile touch sensor jacket, of which we also conducted a usability evaluation. The jacket has a sensor on the wrist of the left sleeve and a device on the left arm. The sensor system can be divided into three main categories: a sensor acting as a switch, a circuit connecting the sensor and the device, and the device that acts as power control and system on/off. The functions are implemented in the texture touch sensor jacket in three modes: cell phone mode, music mode, and PPT presentation mode. We conducted an evaluation of each function in each mode, which indicated that all functions performed well without errors and that the switch had excellent operation for the number and intensity of touch. In terms of usability in a humid environment, the performance of touch functions was found to be equally implemented. In the temperature environment, neither high nor low temperatures caused issues with the functions. A wearing satisfaction assessment evaluated psychological satisfaction, clothing convenience, device convenience, device usability, and device effectiveness. This research jacket is thought to be desirable for the relatively bendable, flexible, and intimate sensor used on the clothing, and the circuit made of conductive fabric tape.

• Journal of Mechanical Science and Technology
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• v.20 no.7
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• pp.1089-1097
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• 2006

The market demand of display devices is drastically increasing in the information technology age. The research on OLED (Organic Light Emitting Diodes) display with the luminescence in itself is being more paid attention than LCD (Liquid Crystal display) with the light source from the back. The vapor deposition process is most essential in manufacturing OLED display. The temperature distribution of the linear cell in this process is closely related to securing the uniformity of organic materials on the substrate. This work analyzed the temperature distribution depending on the intervals between the crucible and the heating band as well as on the amount of the heat flux from the heating band. Moreover, the roles of the water jacket and the configuration of the cover within the linear cell were examined through the temperature analysis for six configurations of the linear cell. Under the above temperature analysis, the variations in the intervals and the amount of the heat flux were considered to have an effect on building the uniform temperature distribution within the crucible. It is predicted that the water jacket and the adequate configuration of the cover will prevent the blowout and clogging phenomena, respectively. The results can be used as the fundamental data for designing the optimal linear cell.

• Human Ecology Research
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• v.62 no.2
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• pp.317-326
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• 2024

This study evaluated the thermal physiological and psychological responses elicited when wearing cold protective jackets with aerogel fillings in two cold environments, one without air velocities and one with air velocities (2.3 m·s-1), at an air temperature of 10℃. The participants were five healthy young males. Measures were taken of physiological parameters, blood pressure (BP), heart rate (HR), core temperature, oxygen uptake (Vo2), and microclimate (temperature and humidity). The psychological parameters evaluated were thermal and wetness sensation. No differences were observed in systolic blood pressure, heart rate, and oxygen intake between the conditions. At tympanic temperature, a significant difference was observed between the conditions during exercise (p<.05); . A significant difference was observed in the microclimate temperature of the clothing according to the airflow, and temperature changes in the chest and back revealed different patterns. Significant differences were observed in thermal sensation (whole body (p<.05), chest (p<.05), back (p<.01)) between airflow conditions. The results therefore indicate that cold protective jackets with an aerogel filling are suitable for people operating in low-temperature and airflow environments.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.1
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• pp.92-101
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• 2010

This study reports on the development of intelligent clothing using a shape memory alloy (SMA) that forms a still air layer and provides thermal insulation depending on the environment temperature. SMA springs were prepared with Nitinol and have an original length of 6mm and a latent length of 20mm with a response temperature of $24.5^{\circ}C$. Hysteresis was evaluated at a temperature between $0^{\circ}C$ and $40^{\circ}C$. An experimental outdoor jacket that was attached with 30 springs was compared with a commercial jacket in terms of the microclimate temperature, humidity, and comfort properties by human subject tests in the microclimate chamber set at $5{\pm}0.5^{\circ}C$. The results showed that the microclimate temperature of SMA embedded clothing system from the wear trials was higher than the commercial ones during the rest period after exercise, especially on the skin side. In addition the thermal, humidity, and comfort sensations of SMA embedded clothing were better than the commercial ones.