• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.150-159
• /
• 2021

This study aimed to prevent inconvenience to electric vehicle users caused by an interruption of charging by the earth leakage breaker trip that occurs during charging. As a field case study, it was confirmed that during the battery charger failure type, leakage current measurement experiment by vehicle type, and leakage current breaker operation experiment, the internal temperature of the charger rose to more than 60 ℃ in summer, and the earth leakage circuit breaker stopped charging by tripping at 80% of the rated sensitivity current. Through Joule heating modeling, 32A is energized at the reference temperature of 30 ℃ at the initial time t=0 (s). After t=3000 (s), the heat generated around the charging part of the earth leakage breaker increased to 32.4 ℃. The temperature and time factors correlated with the amount of heat generated according to the statistical verification tool with a correlation coefficient of 0.97. Overall, it is possible to prevent the leakage breaker sensitivity current trip due to an increase in temperature inside the charger in summer by performing a Joule heating simulation according to the material of the charging case, the arrangement of the internal wiring, and the dielectric medium when developing the charger device.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.16 no.2
• /
• pp.211-218
• /
• 2005

Objectives : The purpose of the study was to evaluate the related factors of depression in mothers bringing their offspring for evaluation or treatment of problematic behaviors. Methods : Fifty mothers were recruited through their offspring's evaluation or treatment for offspring's problematic behaviors. Psychological tests battery including Korean Wechsler Adult Intelligence Scale and the Korean Educational Development Institute-Wechsler Intelligence Scale for Children was administered to all mothers and their offspring. Mothers completed Korean version of Child Behavior Checklist (K-CBCL), and teachers completed Teacher's Report Form (TRF). On the basis of the maternal depression, the mothers were divided into two groups. Results : 1) Among the fifty mothers, $42\%$ of the mothers had depressive disorder, $16\%$ had anxiety disorder, and $42\%$ had no psychiatric disorder. 2) Depressed mothers rated significantly higher in aggressive behaviors, externalizing problems of K-CBCL in their children. 3) Children of depressed mothers had lower score in picture arrangement and coding subtests of KEDI-WISC than those of no psychiatric disorder mothers. 4) After controlling for the total problematic behavior scores of TRF, mother's depression is positively correlated with aggressive behaviors, externalizing problems, total problematic behaviors of K-CBCL, and negatively correlated with coding of KEDI-WISC. Conclusion : Children's aggressive behavior, externalizing behavior, total problematic behaviors and low coding score may be associated with mother's depression.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.17 no.1
• /
• pp.28-37
• /
• 2006

Purpose: Evaluation of vocal cord vibration is very important in cases of voice disorders. There are several equipments for examining the vocal fold vibration such as laryngeal stroboscope, ultra high-speed digital imaging system, and videokymograph. Among these, laryngeal stroboscope is the most popular equipment because of easy to examine the laryngeal pathology. However, current laryngo-stroboscopes are too bulky to move and relatively expensive. The purpose of this research is to develope a portable laryngeal stroboscope of equivalent performance with the current equipments. Methods and Materials: Recently developed high luminescent white LEDs(light emitting diodes) are placed at the head of the endoscope as light sources for the CCD image sensor which is also placed at the head with imaging lens. This arrangement eliminates the bulky light source like expensive halogen or xenon lamps as well as the optical light guiding cables. The LEDs are controlled to flash in phase with the voice frequency of the examinee. The CCD captures these strobo images and converts them into video signals for examinations. Results: There was no functional differences between preexisting stroboscope and the newly developed stroboscope of this study. LED light sources and microprocessor based control circuits of the stroboscope enabled the development of flicker-less, hand-held, portable and battery-operating stroboscope. Conclusion: The developed stroboscope is cost-effective, small-sized, easy to use and very easy desirable to bring and to use in any place.

• The KIPS Transactions:PartC
• /
• v.17C no.6
• /
• pp.471-484
• /
• 2010

In the wireless communication systems, the power consumption of a mobile device is very important issue due to its battery limitations. Hence most of the standards for wireless networks including a mobile WiMAX system are supporting their own power saving mode in way that a mobile device is able to reduce its energy usage while in the mode. However, those standards just define the arrangement of special time intervals, called a paging listening interval, during which the device needs to receive the paging-related control messages, and they do not specify how to effectively reduce the power in many different network environments. This means the amount of power spent by the device is very dependent on the implementations of individual device-vendors, and undesirable paging loss may happen according to the channel conditions. To reduce unnecessary power usage and the risk of paging loss, this paper proposes the effective frequency/BS selection algorithm applicable to a mobile device operating in the power saving mode, which serves the device with better BS based on the tracking for channel variation. This algorithm consists of the channel estimation phase during each paging listening interval, the tracking phase for the measured results, the frequency reselection phase based on the tracking activity, and the preferred BS reselection phase. Thus the proposed method can improve the paging performance while the device is moving in the network. Also the simulation result shows that the presented scheme is superior to other candidates in energy efficiency due to the channel-adaptive frequency/BS selection.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1479-1484
• /
• 2005

A study was conducted to determine the effects of restricted feeding and feed form on the growth performance, characteristics of carcass and digestive tract, and days to first egg of Japanese quail (JQ, Coturnix coturnix japonica). A total of 240 oneweek-old JQ chicks were allocated randomly into 4 experimental groups that consisted of 3 replicates according to a 2${\times}$2 factorial arrangement for two feeding methods (ad libitum, AF and restricted feeding, RF) and two diet forms (mash, MD and crumble, CD). The JQ chicks were placed in a room with floor battery brooders and fed a commercial starter diet from 7 to 14 d of age. According to the experimental design, four treatments (1: ad libitum MD, 2: restricted MD, 3: ad libitum CD, and 4: restricted CD) were applied. Feed restriction was applied by 30% reduction of ad libitum feed intake for both MD and CD from 15 to 28 d of age. All birds were fed ad libitum with treatment diets from 29 d of age until the first laid egg seen (45 d of age). The commercial starter diet, MD and CD were in the same nutrient content (240 g crude protein with 13.4 MJ ME per kg diet). The body weight and overall feed conversion ratio (g feed/g gain) were higher (p<0.05) for the AF quails than the RF at 42 d of age. Carcass weights, dressing percentage and percentage yields of breast and back were similar for AF and RF groups at 42 d of age. The RF delayed (p<0.05) onset of egg production 2 days compared to the AF. Quail fed with the CD showed higher value (p<0.05) for carcass weight and dressing percentage at 42 d of age compared to birds fed with the MD. The interaction effect of feeding method${\times}$feed form on any of the studied parameters was not significant. The results suggest that feed restriction as in the present study can achieve a better feed conversion without reduction in carcass weight, and a significant benefit of feeding the crumble diet over the mash diet was obtained in terms of carcass weight in the JQ.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.2
• /
• pp.143-148
• /
• 1999

Objectives: We studied correlations between neuropsychological tests and perceptual disorder in patients with head trauma and psychiatric patients in order to explore the functional localization of brain in perceptual disorders. Methods: Halstead Reitan Neuropsychological Test Battery, Korean Wechsler Intelligent Scale, and Minnesota Multiphasic Peronality Inventory(MMPI) were administered to one hundred ninteen patients consisting of sixty nine psychiatric patients and fifty patients with brain damage. We tested the correlation between results of neuropsychological tests and peceptual disorder scale PDS) made from nine items related with perceptual disorder in MMPI. T-tests between twenty one higher scorers and seventeen lower scorers of PDS were also performed in the psychiatric group. Results: In brain damage group, significant correlations were found in tests related with function of frontal lobe such as category tests, trail making tests, tactual performance test, and fingertip number writing test, and significant correlations were also noted in the tests related with function of right hemisphere such as tactual performance test, performance, picture completion, picture arrangement and block design. Tests related with subcortical function such as digit symbol test, arithmetic and digit span were signigicantly correlated, too. In psychiatric group, there were significant differences of PDS in the tests related with function of right hemisphere such as picture completion, block design, and right laterality index, and in the tests related with function of left hemisphere such as comprehension, vocabulary, and similarities. Conclusion: Perceptual disorder seems to be related with functions of frontal lobe, right hemisphere, and subcortex in both groups. In a psychiatric group, left hemisphere may be also partially related with perceptual disorder.

• Applied Chemistry for Engineering
• /
• v.35 no.2
• /
• pp.140-147
• /
• 2024

In order to increase the utilization of biomass, an electrochemical performance was considered after manufacturing a carbon anode material (SV-C) for a Setaria viridis-based lithium ion secondary battery through a heat treatment process. When the heat treatment temperature of the Setaria viridis is as low as 750 ℃, the capacitance (1003.3 mAh/g, at 0.1 C) is high due to the negative (-) charge of oxygen present on the surface attracting lithium, along with the low crystallinity and high specific surface area (126 m²/g), but the capacity retention rate is believed to be as low as 61.0% (at 500 cycles and 1 C). In addition, it was confirmed that when the heat treatment temperature increased to 1150 ℃, the carbon layer was condensed to be excellent in arrangement, and the structural defects were reduced, resulting in a significant reduction in the specific surface area (32 m²/g) of the pores. Furthermore, when the surface defects of the anode material are reduced and the crystallinity is increased, the capacity retention rate is as high as 89.7% (at 500 cycles and 1 C), but the degree of defects is small, the active point is reduced, and the specific capacity is considered to be very low at 471.7 mAh/g. In the scope of this study, it was found that in the case of the Setaria viridis-based carbon anode material manufactured according to the heat treatment temperature, the surface oxygen content and crystallinity have higher reliability on the electrochemical properties of the anode material than the specific surface area.