• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.2110-2111
• /
• 2008

Continuous on-line temperature monitoring allows corrective measures to be taken to prevent upcoming failure. Continuous temperature monitoring and event recording provides information on the energized equipment's response to normal and emergency conditions. On-line temperature monitoring helps to coordinate equipment specifications and ratings, determine the real limits of the monitored equipment and optimize facility operations. Using wireless technique eliminates any need for special cables and wires with lower installation costs if compared to other types of online condition monitoring equipment. In addition, wireless temperature monitoring works well under difficult conditions in strategically important locations. Wireless technology for on-line condition monitoring of energized equipment is applicable both as standalone system and with an interface with power quality monitoring system.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.2
• /
• pp.71-83
• /
• 2007

This study created a computerized information system of the collected job analysis data and analyzed the computerized job analysis data to derive critical job factors. Based on the ratings on each critical job factor, possible employment opportunities for the various types of disability could be derived according to the match between job condition and handicap condition. The results can be utilized by the Employment and Vocational Training Administration to expand both the counselor and counselee's perspectives about job possibilities and job requirements.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2008.04a
• /
• pp.281-284
• /
• 2008

The purposes of this study were to make clear the present condition of indoor thermal environment in apartment units and to analyze the relation of the living factors with indoor thermal elements. The field surveys consisted of measurements on physical elements and observations on living factors and interview on resident's subjective responses were carried out in 20 apartment units. The field surveys were carried out during the $January{\sim}March$ 2007. Measuring elements were air temperature, globe temperature, and relative humidity. As results, the averages of indoor temperature each houses were $21.2{\sim}27.2^{\circ}C$, the number of houses exceed the comfort zone were 4. The averages of globe temperature each houses were $21.3{\sim}27.5^{\circ}C$, 6 houses exceeded the comfort zone. The means of relative humidity were $19.5{\sim}58.8%$, relatively dry condition. The clothing value of residents were $0.39{\sim}0.89$ clo(average 0.68 clo). The average of thermal sensation ratings each room were $4.2{\sim}4.8$, 'neutral'$\sim$'slightly warm'. The results of regression analysis on relations of living factors with the thermal elements are as follow; ventilation time(outdoor air exchange), door opening time with balcony, and gas cooker use time had significant effect on indoor temperature.

• Textile Coloration and Finishing
• /
• v.32 no.2
• /
• pp.89-95
• /
• 2020

In this study, the efficacy of Amaranth(Amaranthus spp. L.) as a natural dye resource was investigated for wool fabrics. It is known that a large amount of flavonoid and anthocyanin colorant are contained in leaves and stems, as well as red flowers. The optimum condition of dyeing was 1.3% of dye concentration(o.w.b.) at 100℃ for 60 minutes, resulting the K/S value, 23.43 and R Munsell color on the wool fabrics. Al, Fe, Zinc and Titanium were used as a mordant. The mordant improved the dye uptake, regardless of the mordant type and mordant method. The pre-mordanting method was more effective than the post-mordanting method. Al pre-mordanted fabric showed the highest K/S, 30.02. Light fastness and washing fastness were high in grades 4-5 and 5, and rubbing fastness was good in grades 4 and 4-5 in dry condition, but low in grades 2-3 and 3 in wet condition. The dry cleaning fastness was excellent in all 5 grades. However, the alkaline perspiration fastness ratings were low in grades 2-3 and 3. The results show Amaranthus spp. L. colorant can be used as a functional natural dye for wool fabrics.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.55 no.10
• /
• pp.426-432
• /
• 2006

This paper describes the concepts of Static Line Rating (SLR) and Dynamic Line Rating (DLR) and the computational methods to demonstrate them. Calculation of the line capacity needs the heat balance equation which is also used for computing the reduced tension in terms of line aging. SLR is calculated with the data from the worst condition of weather throughout the year. Even now, the utilization ratio is obtained from this SLR data in Korea. DLR is the improved method compared to SLR. A process for DLR reveals not only improved line ratings but also more accurate allowed line ratings based on line aging and real time conditions of weather. In order to reflect overhead transmission line aging in DLR, this paper proposes the method that considers the amount of decreased tension since the lines have been installed. Therefore, the continuous allowed temperature for remaining life time is newly acquired. In order to forecast DLR, this paper uses weather forecast models, and applies the concept of Thermal Overload Risk Probability (TORP). Then, the new concept of Dynamic Utilization Ratio (DUR) is defined, replacing Static Utilization Ratio (SUR). For the case study, the two main transmission lines which are responsible for the north bound power flow in the Seoul metropolitan area are chosen for computing line rating and utilization ratio. And then line rating and utilization ratio are analyzed for each transmission line, so that comparison of the present and estimated utilization ratios becomes available. Finally, this paper proves the validity of predictive DUR as the objective index, with simulations of emergency state caused by system outages, overload and so on.

• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.132-138
• /
• 2015

This study examined the relative effects of feedback frequency and specificity of Eco-IVIS(eco in-vehicle information system) on the fuel-efficiency and workload. Eighty participants randomly assigned into four experimental groups (high frequency/specific, high frequency/global, low frequency/specific, and low frequency/global feedback) and they drove 16.4Km motorway under the each feedback condition. The dependent variable were fuel efficiency and Drive Activity Load Index which measured participants' subjective ratings of driving workload. The results showed that high frequent feedback was more effective for increasing fuel-efficiency than low frequent feedback, however, there was no significant difference of fuel-efficiency between specific and global feedback. Although, overall DALI score was comparable among four experimental conditions, visual demand score was significant higher under the high frequent feedback condition than low frequent feedback.

• Phonetics and Speech Sciences
• /
• v.11 no.2
• /
• pp.65-76
• /
• 2019

This study aimed to primarily examine perceptions about occupational suitability made by vocational counselors for adults who stutter and associated factors. A total of 69 vocational counsellors (23 per condition) took part in this study and were randomly assigned to recordings related to three different speech conditions (fluent, less-severe stuttering, and severe stuttering versions). The participants were asked to listen to one of the three recordings and rate the speaker's communicative functioning, personal attributes, and suitability for 31 occupations, along with perceptions of the speaking demands and educational requirements of the occupations. Regarding the two stuttering conditions, it was found that suitability ratings were lower for occupations with a high speaking demand than those with a low speaking demand. In addition, the most significant factor associated with occupational suitability ratings was perceived speaking demands, followed by perceived educational requirements, and then by ratings of the speaker's personal attributes. These findings suggest that adults who stutter may face role entrapment (or occupational stereotyping) in workplace settings.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.516-520
• /
• 1991

This paper presents a comparative analysis of two inverter power supply topologies for induction heating and melting applications. The comparison is based on criteria such as resonant condition, component ratings, minimum and maximum operating frequencies, operation under varying load conditions, inverter starting current, and diode reverse recovery time. The voltage source series/parallel resonant inverters are found to offer the best overall performance with respect to converter utilization.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.42_43
• /
• 2009

Ferroresonance is a resonance condition between a nonlinear iron core of a potential transformer (PT) and a capacitance. It can lead to PT voltages several times the normal equipment ratings, and cause the isolation broken and damage to equipments near the PT. This paper proposes a analysis method of PT ferroresonance in the time domain. Based on the simplified equivalent circuit, a differential equation was found and the flux was calculated when ferroresonance generates. The forced response and natural response were also analyzed. The performance of proposed analysis method was verified with the EMTP-RV generated data. The method can help analysis chaotic ferroresonance and periodic ferroresonance.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.5-7
• /
• 2006

Current transformers(CTs) whose rating is selected per a full load current of a feeder in high voltage system can be easily saturated due to high fault current that may be several hundred times of the full load current of the feeder. However, the protective relay shall operate properly at the fault without mis-operation under the CT saturation. So, in selecting the CT rating, it is necessary to consider the behaviour of CT and a performance of protection scheme in condition where CT can be saturated. In this paper, a performance of CT and a degree of saturation are studied and verified whether its ratings are proper for the operation of the protective relay.