• Progress in Superconductivity and Cryogenics
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• v.17 no.4
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• pp.1-7
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• 2015

This paper addresses technical problems of thermal contact conductance or resistance which inevitably occurs in most cryogenic engineering systems. The main focus of this paper is to examine what kind of physical factors primarily influences the thermal contact resistance and to suggest how it can be minimized. It is a good practical rule that the contact surface must have sub-micron roughness level with no oxide layer and be thinly covered by indium, gold, or Apiezon-N grease for securing sufficient direct contact area. The higher contact pressure, the lower the thermal contact resistance. The general description of this technique has been widely perceived and reasonable engineering results have been achieved in most applications. However, the detailed view of employing these techniques and their relative efficacies to reduce thermal contact resistances need to be thoroughly reviewed. We should consider specific thermal contact conditions, examine the engineering requirements, and execute each method with precautions to fulfil their maximum potentials.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1194-1197
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• 2006

Recently, international standard for measurement of sound absorption in a reverberation room has been amended. In the revised version, temperature, humidity and air pressure conditions are strictly restricted and also the concrete procedures are presented to reduce the differences in test results by adding inspection of diffusion, measurement uncertainty etc. In this paper, the systematic tests are conducted based on the inspection guide of diffusion defined by ISO 354 and the effects of diffusers on the measurement of sound absorption ratio are considered. As a result, we perceived that the averaged sound absorption ratio in mid and high frequency range is expected to measure around $0.05{\sim}0.1$ higher in high sound absorption material. Therefore, as for the reverberation room for measurement of sound absorption, we need to take into consideration not only the spatial standard deviation of sound pressure mandated by ISO 3741, but also, inspection regulation of diffusion showed by ISO 354.

• KSBB Journal
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• v.14 no.4
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• pp.482-489
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• 1999

As host for the production of eucaryotic heterologous proteins, methylotrophic yeast Pichia pastoris and Hansenula polymorpha are the most highly developed of a small group of alternative yeast species chosen for their perceived advantages. This paper describes the method to enhance the recombinant protein productivity with P. pastoris and H. Plymorpha. In these experiments, the effects of methanol induction timing, induction method, pH, culture temperature and kinds of nitrogen sources on foreign protein production were tested with P. pastoris and compared with H. polymorpha.. In addition, optimum methanol concentration as inducer and the effects of carbon sources on AOX1 or MOX promoter repression and secretion efficiency were also studied in both cases.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1224-1227
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• 2009

When evaluating the quality of images and displays, it is important to combine the characteristics as perceived by the human visual system and measured by equipment using subjective and objective methods, respectively. In the case of objective methods, the quality of a display is measured using colorimetric or radiometric devices according to existing standards covering the color temperature, gamut size, gamma characteristic, and device characterization. Meanwhile, subjective methods assess the quality of an image using the human visual system based on a comparison with a reference or counterpart using such metrics as the sharpness, noise, contrast, saturation, and color accuracy. Objective and subjective methods are usually used together in comparison, as ultimately it is observers watching images on a display. In addition to existing objective methods, a new image quality metric is also introduced as regards the JPEG compression ratio that is reflected in the relationship between the gamut size and the color fidelity in CIELAB color space.

• Korean Journal of Community Nutrition
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• v.11 no.2
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• pp.240-252
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• 2006

A survey was implemented to suggest basic data for assuring the safety of cooked foods in foodbank operations. A questionnaire consisted of total 48 items including general characteristics, basic inputs and perceived importance/performance of sanitary management. One hundred twenty-eight responses among the 267 nationwide foodbanks were used for the statistical analysis. About forty-one percent of foodbanks was operated a period of 1-3 years and 43.0% of them were managed by social welfare organizations. The number of staff was only 0.5 person per operation with the whole responsibility and 1.0 with additional work, and thus most of the work was managed by volunteers. Job satisfaction was shown to be moderate and was affected by specialty and salary mostly. The facilities and equipment in foodbanks were not enough to operate and freezers/refrigerators were the top priority to supplement. Most of the respondents attended a nationwide level sanitary education program (79.7%); but complained not enough frequency of education (90%). The sanitary status of the donated foods was considered as satisfactory but some safety practices had to be improved, including personnel expenses and operating costs in the district level, a sanitary awareness of the donors and a general management of the facilities arid equipment. An assessment on sanitary management resulted in an overall average of 4.45 out of 5 points in importance and 3.85 in performance showing the high level of sanitation perception in foodbank managers. From the IPA analysis, the fields found to be improved were sanitation management during cooking and temperature control as well as cleanliness and sanitation of both transport vehicle and refrigerator/freezer. To secure the food safety in foodbanks, consequently, personnel support, supplement of facilities and equipment, intense sanitation education and development of sanitation management program is needed.

• Journal of Magnetics
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• v.7 no.2
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• pp.29-39
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• 2002

The initial NiCuZn synthetic ferrite were acquired from thermally decomposing the metal nitrates $Fe(NO_3)_39H_2O, Zn(NO_3)_26H_2O, Ni(NO_3)_26H_2O, and Cu(NO_3)_23H_2O$ at $150^circ{C}$ for 24 hours, and then we calcined the synthetic powder at $500^circ{C}$, pulverized each of those for 3, 6, 9, 12, and 15 hours in a steel ball mill, sintered each at $700^circ{C}$ to $1,000^circ{C}$ for 1 hour, and thus studied their microstructures and electromagnetic properties. We could make the initial specimens chemically bonded in liquidity at a low-temperature $150^circ{C}$, by using the low melting points less than $200^circ{C}$ of the metal nitrates instead of the mechanical ball-mill pulverization, then narrow a distance between the particles into a molecular one, and thus lower the reaction point of sintering by at least $200^circ{C}$ to $300^circ{C}$. Their initial permeability was 50 to 400 and their maximum magnetic induction density and coercive force, 2,400 G and 0.3 Oe to 0.5 Oe respectively, which was similar to those of NiZnCu ferrite synthesized in the conventional process. In the graph of initial permeability by frequencies, a $180^circ{C}$ rotation of the magnetic domains which appears in a broad band of micro-wave before and after the resonance frequency, could be perceived.

• Journal of the Korean Geographical Society
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• v.37 no.4
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• pp.385-402
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• 2002

This study examined temporal and spatial patterns of bioclimatic perceived sultriness in South Korea by analyzing the climatology of heat index calculated from ambient temperature and relative humidity for the period of 26 years (1973-1998). As results, spatially, bioclimatic sultriness above all thresholds frequently occurred mainly in the central western inner area, the southwestern inner area, and the southeastern inner area of South Korea. Especially, Miryang in the southeastern inner area of South Korea was proved to be, bioclimatically, the sultriest area in South Korea that has recorded frequent high heat index. Temporally, frequency of sultriness in the contiguous South Korea significantly increased in the 1990s. Specifically, In 1994, frequencies of heat index exceeding each threshold was the highest all over South Korea. Normally, the sultriness with high heat index exceeding 40.6$^{circ}C$ occurred mainly for the period of between the end of July generally after Summer Changma and the beginning of August before another small rainy season of years. These temporal-spatial distributions of bioclimatic sultriness in South Korea showed various patterns regionally, affected by physical and anthropogenic climatic factors such as topography, latitude, altitude, water bodies or aforestration, urbanization, and industrialization as well as movements of large-scale air masses.

• The Korean Journal of Community Living Science
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• v.25 no.2
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• pp.233-246
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• 2014

This study investigates the level of satisfaction with quality attributes of meal services for low-income children in Wonju, Korea. Based on interviews with 287 subjects (users of meal boxes: 17.4%, card users: 82.6%; boys: 48.4%, girls: 51.6%; elementary school students: 44.4%, middle school students: 33.0%, high school students: 22.6%; two parents household: 29.8%, single- or no- parent household: 70.2%) through consent from their guardians, some key characteristics of the subjects and the relationships between their characteristics and the level of their satisfaction with meal services were examined. According to the results, the level of satisfaction ranged from 54.7% to 66.0% (those respondents indicating "very good" and "good") indicated that the meals were generally acceptable. The highest level of satisfaction was for sanitation (66.0%), followed by taste (64.0%), ease of choosing preferred menu items (61.9%), a proper temperature (61.9%), a sufficient amount (60.8%), diversity (56.3%), the comfortableness of the dining area (54.7%), and sufficient nutrition (41.0%). For these eight quality aspects of meal services, users of meal boxes were more likely to be satisfied with the comfortableness of the dining area, whereas card users, with the taste and temperature of the food. The type of meal service, the attitudes toward talking to friends about supporting meals, and subjectively perceived health status had significant effects on the level of satisfaction with meal services.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.2
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• pp.342-353
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• 2020

The purpose of this study was to evaluate far-infrared clothing (FIR condition) with non-far-infrared clothing (Control condition) to assess the effects of FIR on thermo-physiological responses. Eight young healthy males (23.0±2.3 yr, 176.5±3.7 cm, and 69.0±4.3 kg) participated in this experimental trial, which consisted of a 20 min rest followed by a 40 min walk (4.0 km·hr^-1) and a 20 min recovery at 20℃ with 50%RH. The results showed that finger skin blood flow and mean skin temperature were significantly higher for the FIR condition than the control during exercise and recovery (p<.001). Clothing microclimate temperature of the FIR condition was 0.5℃ higher on the back (p=.001) and 0.4℃ higher on the thigh (p=.015) during recovery. Clothing microclimate relative humidity of the FIR condition was 13% higher on the chest (p=.006) and 19% higher on the back (p<.001) during exercise than control. Subjects felt warmer and more comfortable in the FIR condition than in the control (p<.05). Perceived skin wettedness (%BSA) was less in the FIR condition than in the control (p=.001). These results indicate that ceramic-embedded clothing had significant effects on thermoregulatory responses for light activity in an indoor environment.

• Korean Journal of Adult Nursing
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• v.12 no.4
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• pp.666-677
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• 2000

The purpose of this study was to identify the needs which were perceived by patients who were received spinal anesthesia for surgery. The subjects consisted of 50 adult patients who were admitted to 2 university hospitals and 2 general hospitals in Pusan city and 1 general hospital in Koje City for surgery under spinal anesthesia. Thirty eight percent of subjects received information about anesthesia before the operation. The instrument for this study was developed by the researcher based on literature and a pretest. Data were collected from December 10, 1999 to February 10, 2000 and were analyzed by content analysis. The results were that there were 533 meaningful statements in the needs of spinal anesthesia patients. The needs of spinal anesthesia patients had 51 items (preoperation (6), induction of anesthesia(5), intraoperation (27), postoperation(13)) and 6 categories (information, emotional welfare, physical welfare, post anesthetic management, control of physical environment, humane treatment). From the results, it can be concluded that: 1. In the pre-operation period, we have to explain anesthesia procedures, adequate position of anesthesia, duration before anesthesia wears off and sensation of paralysis. We have to supply emotional support to relieve anxiety because of anesthesia. 2. In induction of anesthesia, we have to support patient's position for anesthesia, and relieve anxiety so that patients participate in induction of anesthesia well. 3. In intra-operative period, we have to check the level of anesthesia, and keep up a comfortable position for operation and care for physical discomfort such as thirst, nausea, vomiting, dyspnea and to maintain body temperature of the patient. Since the patient is conscious, we have to communicate with the patient to relieve anxiety, maintain privacy, inform the patient of the process of the operation and encourage the surgeon to explain the outcome of the operation. The operating team needs the careful about what they say and to place the instrument well. We have to ventilate the room air and reduce noise. 4. In the post-operative period, we have to explain the purpose and duration of bed rest, complications of anesthesia and care for physical discomfort such as pain, dysuria, headache, backache. Also we have to maintain body temperature of the patient and maintain privacy.