• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.12
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• pp.1237-1242
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• 2012

No matter how low it might be, noise from home appliances in indoor environment cause displeasure for residents as it is produced nearby. Electronic goods including vacuum cleaner and washing machine generate high frequency noise, which interrupts TV-watching or conversations and cause noises between floors in apartment houses. In particular, refrigerators make constant noise late at night, hampering the study for exams and causing sleeplessness. Korea, despite the government's efforts to promote low-noise goods based on the noise test by corporation, there is a lack of standardization in the test method, test condition and measuring equipments. This is a major reason that lowers the reliability of low-noise products. At present, low-noise home appliances are certified with eco labeling in the nation but, only 7 brands of refrigerators, 4 brands of washing machines and 97 brands of air-conditioners obtained certification as of august, 2011. In addition, none of Kimchi-refrigerator and vacuum cleaner brands were approved as low-noise home appliances. This shows Korea's relatively underdeveloped market for low-noise products, which, in part, is because of the difficulties companies face in being certified with eco labeling as they should satisfy various requirements such as power-saving and eco-friendly design besides low-noise features. As a result, low-noise labeling for home appliances should be established for the revised noise and vibration management law and the study was carried out to establish low-noise labeling system for major noise sources including vacuum cleaner, washing machine, air-conditioner and refrigerator.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.3 s.31
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• pp.286-294
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• 1989

This Study has treated the effects of fiber, surfactants, temperature, surfactant concentration, pH, electrolyte, fatty acid contents and mechanical force on the removal of particulate soil from fabric, vacuum cleaner dirt was used as model particulate soil. The fabrics were soiled with mixture of vacuum cleaner dirt and fatty soil, and washed in Terg-O-tometer. The detergency was evaluated by measuring reflectance of a fabric before and after washing. The results were as follows. 1. The fiber type showed a different pattern of soil removal with surfactants. In general, particulate soil removal increased in the following order Acetate>PET. Nylon>Cotton. Particulate soil removal, which is affected by the surfactant type, increased in the following order NPE $(EO)_{10}\leqq$Soap>SLS>DBS>Tween 80. 2. The influence of temperature on the particulate soil removal was very complex because efficiency of removal was varied with surfactant and fiber types. The washing efficiency of NPE $(EO)_{10}$ was highest at around $40^{\circ}C\;and\;60^{\circ}C$ with cotton and PET but the washing efficiency of DBS was the highest at $60^{\circ}C$ with cotton, decreased monotonously with increasing temperature with PET 3. The detergency of particulate soil increased with increasing surfactant concentration at relatively low concentration and then levelled off above some optimum concentration. 4. The removal of particulate soil increased with increasing pH and mechanical force. 5. Effect of electrolyte on the particulate soil removal was depended on the concentration of the surfactant. At low concentration of surfactant, addition of electrolytes improved soil removal but above the some concentration no effect was observed. At high concentration of surfactant, Vie., $0.6\%$ , the maximum washing effect is reached without added electrolyte. These result indicate that added electrolyte only influence the adsorption of surfactant on the soil and fiber 6. Fatty acid content in the soil did not influence on particulate soil removal without regard to surfactants.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.97-102
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• 2016

In this paper, a bidirectional power supply charger is proposed. This system used a solar cell panel to generate electricity and used super capacitors to store these energies, which can be used for the robot cleaner or some other electronic products. This system include a phase-shift controlled bidirectional dual active bridge (DAB) converter, solar panel super capacitors and DSP controller. In the daytime it can charge to the super capacitors to store the energy generated by the solar cell panel and in the night it will release the energy stored in the super capacitors to loads. A prototype of the proposed bidirectional power supply charger system was designed which can achieve 18V to 30V input, 10V/20W output to super capacitors and 9V/6.5W output when it acts as a charger for the robot cleaner. The system is verified to be sTable and reliable by both the simulation and experimental results.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.3
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• pp.3-15
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• 2003

The concept of 'Cleaner Production(CP)' and various activities aiming at promoting CP are investigated along with the applicabilities of CP to marine environment. Although the conventional approaches dealing with the marine pollutions can be absorbed in CP, the whole activities of Production and conservation in the ocean must be projected into a new Paradigm, 'Sustainable Development.' Renewable energy is the first key to a complete CP and the ocean can provide us with the clew. In order to introduce CP system more effectively to marine environment opinion collection, environment monitoring, problem identification, resolution proposition, state-of-the-art evaluation, policy development, communication, education and public information are to be Planned and followed up systematically KOSMEE is believed to be a good structure to stand at the center of the upcoming CP activities in the ocean.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.407-414
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• 2007

Using the MPI (Moldflow Plastics Insight) software from Moldflow Co., the optimum conditions for producing the upper part of the automobile air cleaner were obtained for 20% talc filled polypropylene (PP). The analysis was carried out to solve the cracking problem between upper and lower parts and the improved process was proposed using the flow balance. The comparative results between the conventional process, CASE-1, with one-pin gate and the new process (CASE-2) comprising two-pin gate system are the followings. In the case of CASE-2, the shorter filling time and reduced cycle time induced an improved production and processibility. In addition, the orientation and volumetric shrinkage are similar to those observed in the lower part, but the assembly, deformation, and physical characteristics are enhanced. The problem induced by the CASE-1 did not originate from the residual stress, but from the difference in the size of the upper part air cleaner after shrinkage. Thus, the orientation problem was expected to improve by optimizing the gate structure.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.8
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• pp.1178-1187
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• 2006

The purpose of this study is to conduct a questionnaire survey on the actual conditions of the working uniform and protective equipment put on by street cleaners, then to identify their inconvenience and problems and to draw solutions to improve them, and finally to design a spring-and-autumn street cleaner uniform which has enhanced functionalities such as motional flexibility, safety and soil proof. The questionnaire survey of this study was done by street cleaners who were in charge of street cleaning and collecting the recyclable waste. The result of this study, easily worn-out parts of the working clothing were the sleeve hems and the front part on the upper uniform, and the trouser hems and zipper on the lower uniform. Easily soiled parts were the sleeve hems, parts of arm on the upper uniform, and the trouser hems and knee parts on the lower uniform. Based on the results of the questionnaire survey, the sample uniforms were designed in consideration of material, design and pattern. A soil-proof material was used for easily soiled parts such as sleeve hems, knee parts and trouser hems. Reflective material was applied to the parts such as chest, back and the side lines of sleeves and trousers to raise visibility in working and to ensure safety. A crease was given to each side of the back. The height of sleeve cap was lowered to lift the motional flexibility of back and arm parts. Darts were applied to elbow and knee parts for a three-dimensional design. Gussets were inserted in the thigh part to give it activity. Then quantitative evaluation and a sensory evaluation, which was composed of outward appearance, motional flexibility and fitness for field operation, were conducted. According to these evaluations, the sample uniform was found to be more satisfactory than current uniform.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.323-330
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• 2001

The regular maintenance and repair status of major farm machinery such as power tiller, farm tractor, rice transplanter and combine harvester etc., were surveyed and analyzed for the full-time farmers in order to get basic information for promoting farm machinery productivity. The survey was carried out through 209 farmers from 9 provinces. The results of this study can be summarized as follows; 1. The regular maintenance of farm machinery was conducted at repair shop(49.5%) or dealer agency(12.0%), and also conducted by farmers at their house(34.9%). 2. For the status on the cleanness or exchange times of engine oil, fuel filter and air cleaner, most farmers conducted fewer times than the necessary times. And, 5.3%, 7.7%, and 2.9% of surveyed farmers experienced breakdowns due to the insufficient cleanness or exchange oil, fuel filer, and air cleaner, respectively. 3. Most farmers(76.1%) recognized the necessity of farm machinery training or education, and they preferred one week for the training period, simple or easy maintenance for the training level, agricultural technical center or farm machinery manufacturer for the training agency. 4. Complete recognition of operation manual and sufficient maintenance before-, during-, and after-operation for the farm machinery can minimize the breakdowns, enlarge the endurance prevent the safety accidents, and promote productivity of farm machinery. And, these can be accomplished by the thorough training or education for agricultural machinery.

• Journal of the Korean Home Economics Association
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• v.50 no.5
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• pp.51-65
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• 2012

The purpose of this study is to provide empirical basic data to develop public uniforms design, by understanding international universality and advanced design sense, through the analysis of public uniforms design at home and abroad. The theoretical study reviewed the character and area of public design, and the concepts and requirements of public uniforms. The empirical study analyzed public uniform design at home and abroad, focusing on typical public uniforms, such as police, fire fighter, and street cleaner. The results of this study were as follows. First, the police uniform has a standardized and formal suit style, which consists of a single-breasted dk-PB jacket with a notched collar and pants. It uses PB as the main color, to show their authority and role reliability. Epaulet or badge, which represents belonging and difference in rank, are attached to express the identity of an organization. Second, the fire fighter uniform consists of a hip length coat with a stand collar effective for heat shielding, and straight pants with flap pockets, in which it is easy to put things. Its main color is dkg-PB, to mitigate visual fatigue and enhance comfort, and an accent color scheme is used, to effectively raise visual attention and safety. Finally, the street cleaner uniform has a casual style, which consists of a jumper with a shirt collar and pants for high activity. v-YR and R with high chroma is mainly used, for increased attention during day and night work, to stress safety.

• Clean Technology
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• v.14 no.2
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• pp.103-109
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• 2008

In this study, in order to develop evaluation method of the cleaning efficiency of residual flux which remains on the surface after soldering with solder paste, a specially designed metal tool is used to reduce spread uncertainty of flux while soldering. Using this tool, the measurement of cleaning efficiency of flux after soldering for some typical alternative semi-aqueous cleaners and 1,1,1-TCE by weighing method was conducted. As the test result of cleaning efficiency for each cleaner at several different cleaning times, the precision of the data is confirmed to within about 4% relative standard deviation (RSD) range. So, it is considered that this would be a good evaluation method for evaluating the cleaning efficiency of the residual flux which remains after solder paste soldering in the alternative cleaning. The results of this test method shows that the cleaning efficiency of ST 100SX and Neozal 750H in the cleaning of residual flux was better than other semi-aqueous cleaners, but its cleaning efficiency was clearly inferior to 1,1,1-TCE.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.247-251
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• 2001

Universal motors are mainly used for vacuum cleaner application. There are a lot of researches on SRM that applys home appliance throughout the world. The manufacturing cost of SRM drive makes it hard to expand its application to home appliance. This paper presents Single Phase SRM for the vacuum cleaner that has advantge in cost and performance over conventional universal motor. This paper proposes new power device driving scheme by using SRM switching characteristic. The driving scheme is very simple and inexpensive. Dwell Time Control method is used for the minimum switching loss of power device. The switching frequency of power device is less than 4.5kHz at 45,000rpm. By use of this scheme, power device based on very small switching losses can be used on SRM drive. Also, the biggest problem in single phase SRM is starting, this paper shows a new starting algorithm with two hall sensors, accelerating and running sensors, respectively. Finally, the proposed Single Phase SRM achieves higher efficiency and long life time compared to universal motor. Its life time is more than 1500 hours. Its life time is extended 4 times than that of conventional motor and its suction power is increased $20\%$ at the same volume of conventional universal motor.