• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.141-149
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• 2004

The automobile equipped with a gasoline engine uses the ignition coil, namely, a high voltage generator, to make the mixed fuel ignited and burned in the combustion chamber, which results in the power to drive the engine. The ignition coil functions to convert a low voltage of the primary into a hiか voltage of the secondary by switching method, which will be transmitted to the electrode. Here, if the ignition coil has a defect even a little, it cannot function well. In this study, it was chosen epoxy molding ignition coil in recently and epoxy resin which is insulation material as specimens, and it was measured the characteristics of the partial discharge occurring to the specimens when those were applied to a voltage, and thereby, it was researched and analyzed the distribution of phase angle, amount and count of discharge due to the changing voltage, And as the result is applying to the actual automobile ignition system, it can be expected the enhancement of the performance of the ignition coil and the reliability of the electrical equipment.

• KIEAE Journal
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• v.14 no.4
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• pp.111-117
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• 2014

In South Korea, the government has recently enforced regulations associated with buildings. Temperature restriction in indoor environment is one of the common ways of energy reduction in order not to dissipate heating and cooling energy; however the people who are in restricted temperature feels uncomfortable. Furthermore, occupants cannot feel the same thermal sensation even they are in the same place. For the reason, occupants should express their thermal sensation and HVAC system should be able to apply their demand. It is proved by an adaptive principle. The adaptive model means that people react in ways which tend to restore their comfort, when change occurs such as to produce discomfort. In order to design HVAC control strategies based on adaptive model, we designated an existing office building as a reference building to gather data from actual field. Furthermore, we gathered occupants' thermal sensation and clothing insulation in real-time. We filtered the data with Kalman's filter method. The data was reasonable when there is an alarm messages for asking questionnaire. The response ratio were different in occupants' thermal condition. In conclusion, the filtered occupants' thermal sensation can be used as a real time HVAC control and input value of HVAC control.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.6
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• pp.509-513
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• 2000

The physical and electrical characteristics of MgO and Pt thin-films on it deposited by reactive sputtering and rf magnetron sputtering respectively were analyzed with annealing temperature and time by four point probe SEM and XRD. Under annealing conditions of 100$0^{\circ}C$ and 2 hr, MgO thin-film had the properties of improving Pt adhesion to SiO$_2$and insulation without chemical reaction to Pt thin-film and the sheet resistivity and the resistivity of Pt thin-film deposited on it were 0.1288 Ω/ and 12.88 $\mu$$\Omega$.cm respectively. We made Pt resistance pattern on SiO$_2$/Si substrate by life-off method and fabricated Pt thin-film type microheater for thermal microsensors by Pt-wire Pt-paste and SOG(spin-on-glass). In the temperature range of 25~40$0^{\circ}C$ we estimated TCR(temperature coefficient of resistance) and resistance ratio of thin-film type Pt-RTD(resistance thermometer device). We obtained TCR value of 3927 ppm/$^{\circ}C$ close to the bulk Pt value. Resistance values were varied linearly within the range of the measurement temperature. The thermal characteristics of fabricated thin-films type Pt micorheater were analyzed with Pt-RTD integrated on the same substrate. The heating temperature of Pt microheater could be up to 40$0^{\circ}C$ with 1.5 watts of the heating power.

• Korean Journal of Bronchoesophagology
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• v.12 no.2
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• pp.19-25
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• 2006

There have been numerous modalities to recover blink function of orbicularis oculi muscle in patients with facial paralysis. However, there is still no optimal method for reanimation of eyelid. In this study, we tried to recover blink function of paralyzed rabbit's eyelid with the ion polymer metal composite (IPMC) which is one of the electroactive polymers that is spotlighted as artificial muscle. We manufactured IPMC by plating the platinum over perfluorosulphonic acid polymer ($Nafion^{(R)}$). IPMC was coated by Norland optical adhesive for the purpose of insulation and keeping it from dry. IPMC modifications by roughening the surface of Nafion, repetitive plating (maximum 4 times) with platinum, and lengthening the width of IPMC were done. The facial paralysis was induced in the rabbit by sectioning of facial nerve at the main trunk. After minimum period of 4 weeks, IPMC was inserted in the paralyzed rabbit's eyelid. By modification, the force generated by IPMC was enhanced. Restoration of blink function in paralyzed rabbit was achieved on electrical stimulation of the IPMC by 5 voltage direct current. IPMC can be promising option for facial reanimation, but further studies are needed to enhance the efficiency of IPMC.

• Journal of the Korean Home Economics Association
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• v.27 no.4
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• pp.167-191
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• 1989

The present study was conducted to devlop and appropriate retirement home model for the elderly in terms of clothing and textiles; nutrition, health, and foodservice; housing and environment; and psychological adaptation. Specifically, the purposes of the study were: 1) to provide basic guidelines for clothing by comparing the clothing behavior of the elderly living in the retirement home and those living in their own homes with family, 2) to provide basic guidelines for balanced diet and effective foodservice, 3) to develop an ideal life space and facilities, and 4) to assess the psychological characteristics of the elderly. Questionnaires, observation, experimental method, and survey of literature were used for the study. Clothing behavior showed that the elderly were much concerned about clothing, and they preferred comfortable as well as fashionable designs. The elderly in the retirement homes complained of a lack of quantity and variety in clothing. They preferred natural fiber rather than blended fabrics. Flame resistance, thermal insulation, and flexibility of textile fabrics were found to be prime considerations in manufacturing and selecting clothing materials for the elderly. The health status of the surveyed elderly was generally good, but some poor eating habits were observed. Dietary nutrients intakes were generally sufficient, but several nutrients intakes were insufficient. The level of equipment in the kitchens of the institutions was low. Furthermore, the employment rate of dietitians in institutional settings was extremely low. This resulted in a lack of systematic foodservice management. Residents in the institution were generally satisfied with present life space and facilities but this was mainly because of abandonment, adaptation, and past experience. Optimal allocation of residents per bedroom and an adequate design for storage, bathroom, utility room, and dining room were recommended. The comparison of psychological status of the elderly living at home was more stable than those living in an institution. The emotional state of the elderly living in the institution was characterized by loneliness; they did not have close interpersonal relationships or future plans. An appropriate model for the elderly was developed on the basis of these findings.

• KIEAE Journal
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• v.16 no.3
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• pp.113-119
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• 2016

Purpose: In this study, we evaluate the annual energy performance of the detached house which was designed with the aim of zero energy. Method: The experimental house which was constructed in Gonju Chungnam in 2013, is the single family detached house of light weight wood frame with $100m^2$ of heating area. Thermal transmittance of roof (by ISO 10211) and building external walls are designed as $0.10W/m^2K$ and $0.14W/m^2$ respectively and low-e coating vacuum window glazing with PVC frame was installed. Also grid connected PV system and natural-circulation solar water heater was applied and 6kWp capacity of photovoltaic module was installed in pitched roof and $5m^2$ of solar collector in vertical wall facing the south. We analyzed the 2014 annual data of the detached house in which residents were actually living, measured though web-based remote monitoring system. Result: First, as a result, total annual energy consumption and energy production (PV generation and solar hot water) are 7,919kWh and 7,689kWh respectively and the rate of energy independence is 97.1% which is almost close to the zero energy. Second, plug load and hot water of energy consumption by category showed the highest numbers each with 33% and 31%, with following space heating 24%, electric cooker 8%, lighting 3% in order. Hot water supply is relatively higher than space heating because high insulation makes it decreased.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1137-1140
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• 2014

Faulty electric motors onboard vessels with anomalies in windings or poor insulation are usually repaired at land based workshops and reinstalled in place by crew hands after receiving the repaired motors. Especially for 3 phase induction motors which need Y-${\delta}$ starters with 6 lead wires, it would happen that the polarities of stator windings cannot be well distinguished if the original tags of these wires are erased or not visible clearly, resulting in subsequent damage to the repaired motor due to extreme current flow when the power is given to the motor the stator windings of which are wrongly connected in the polarity. This study proposes an easy way to make correct connection in winding polarities without failures based on the electro-magnetically induced voltages on windings when a slight DC current is supplied to a winding coil by using an analog multi-tester. The proposed method is applied to actual motors and delves into the applicability for polarity discrimination through a few measurements onboard vessels.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.788-792
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• 2003

Rotating machines are widely used in industrial world and especially motor and generator take up much part of it. As for this kind of motor and generator, electrical loss due to eddy current is the very important factor and that is also a primary factor causes heat generation. To solve this kind of problem like the above. insulated laminating silicon steel sheet is used to prevent eddy current effect. Laminated rotor is widely used as rotating shaft of motor and generator. Due to that, electrical loss and heat problem can be solved but designer meets another problem. In general. most of the motor and generator can be normally operated under 3,600 rpm because they are designed to have the first critical speed more than that speed. But nowadays, they should be operated more than the first critical speed as usual with the trend of high speed, large scale and high precision in industrial world. The critical speed can be determined from the inertia and stillness for the rotor and bearing of rotating systems. The laminated rotor stiffness can be hardly determined because it can be derived a lot factors for instance rotor material and shape, lamination material and shape, insulation material. lamination force and so on. In this paper, the change of the natural frequency of the motor was examined with the change of the lamination force as an experimental method and design criteria will be presented for motor & generator designer, who can apply the result of numerical analysis with equivalent diameter scheme with ease.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.1
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• pp.39-46
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• 2008

The end plates of fuel cell assemblies are used to fasten the inner stacks, reduce the contact pressure, and provide a seal between Membrane-Electrode Assemblies (MEAs). They therefore require sufficient mechanical strength to withstand the tightening pressure, light weight to obtain high energy densities, and stable chemical/electrochemical properties, as well as provide electrical insulation. The design criteria for end plates can be divided into three parts: the material, connecting method, and shape. In the past, end plates were made from metals such as aluminum, titanium, and stainless steel alloys, but due to corrosion problems, thermal losses, and their excessive weight, alternative materials such as plastics have been considered. Composite materials consisting of combinations of two or more materials have also been proposed for end plates to enhance their mechanical strength. Tie-rods have been traditionally used to connect end plates, but since the number of connecting parts has increased, resulting in assembly difficulties, new types of connectors have been contemplated. Ideas such as adding reinforcement or flat plates, or using bands or boxes to replace tie-rods have been proposed. Typical end plates are rectangular or cylindrical solid plates. To minimize the weight and provide a uniform pressure distribution, new concepts such as ribbed-, bomb-, or bow-shaped plates have been considered. Even though end plates were not an issue in fuel cell system designs in the past, they now provide a great challenge for designers. Changes in the materials, connecting methods, and shapes of an end plate allow us to achieve lighter, stronger end plates, resulting in more efficient fuel cell systems.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.9
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• pp.867-873
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• 2010

The failure of water-cooled generator stator windings as a result of insulation breakdown due to coolant water leaks and water absorption often occurs worldwide. Such failure can cause severe grid-related accidents as well as huge economic losses. More than 50% of domestic generators have been operated for over 15 years, and therefore, they exhibit signs of aging. Leaking and water-absorbing windings are often found during an overhaul. In an existing method for evaluating the integrity of generator stator windings, the drying process of the interior of the windings is ignored and only final leak tests are performed. In this study, it is shown that water leaks and water absorption in stator windings can be detected indirectly through vacuum pattern analysis in the vacuum drying mode, which is the used in the preparation stage of the leak test.