• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.2
• /
• pp.81-89
• /
• 2002

The Battery Energy Storage System (BESS) has lots of advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. However, it is very critical that economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS in nation widely. In this paper, we proposed the economic assessment model of customer owned BESS which is complemented and improved the existing model. The proposed model is applied to the typical customer types, i.e. light industrial, commercial, and residential, which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic viability performed for each customer load type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, Net Present Worth (NPW), Rate Of Return (ROR). The results show that the BESS has economic benefits to the specific customer type, i.e. residential customer. Therefore, the government and the energy agency should be committing the support program, such as tax incentive, financial support, to disseminate the BESS nation widely. The results of this paper are useful to the customer investment decision-making and the national energy policy & strategy in Korea.

• Journal of Preventive Medicine and Public Health
• /
• v.32 no.2
• /
• pp.162-169
• /
• 1999

Objectives: The aim of this study was to investigate the attitudes toward complementary and alternative medicine among 1,490 residents(339 households) in Suwon city. Methods: All respondents were asked about types, frequency, effects, side-effects, views, and cost of complementary or alternative medicine through a questionnaire from July 24th to 27th. Six therapies were investigated: diet; acupuncture/ massage/ chiropractic etc., mind control such as Ki/ Yoga/ spiritual therapy/ relaxation therapy etc.; nutritional supplements, cultural remedies; and Herb medications Results: The results of this survey were as follows: 35.6% of respondents had experiences with at least one or more types of complementary and alternative medicine. The average number of different types of therapies used was 3.4. More experience with various types of therapies were found among those respondents of higher education, older age group, higher income, married group, religious group than among the opposite groups of respondents. Herb medications were used most frequently(39.8%), followed by minor grains(37.9%), Ginseng(23.8%), Boshintang(21.5%), acupuncture(20.3%), Gaesojou(15.3%) Gingko nut(12.0%), mushroom(11.5%), Cupping therapy(10.2%), and black goat(0.0%). Acupuncture and Herb medications were used for treatment of hypertension the most frequently; minor grains or silkworm for treatment of diabetic mellitus; vegetables for treatment of obesity; acupuncture, Cupping Therapy, Herb medications for treatment of rheumatism; and acupuncture, Herb medications, or exercises for treatment of Cerebro Vascular Accident(CVA). The average costs of treatment were 108,000 Won for hypertension, 87,200 Won for diabetic mellitus, 16,800 Won for obesity, 68,800 Won for rheumatism, and 87,500 Won for CVA. Among 10.9% of respondents, there were 13 cases of side-effects with acupuncture, Herb medications, and Gaesojou. Among the cases of side-effects, majority was due to Herb medications. Respondents reported that Cupping Therapy was the most effective, followed by acupuncture, Ginseng, Gingko nut, Boshintang, black goat, minor grains, Gaesojou, Herb medications, vegetables, and mushroom. In response to the views of complementary and alternative medicine which they had used, they recommended minor grains first, followed by Ginseng, acupuncture, Gingko nut, Cupping Therapy, vegetables, Boshintang, black goat, mushroom and Herb medications. In contrast, they did not recommend Herb medications, acupuncture, nor Gaesojou. Conclusions: These findings indicate that many people use various complementary and alternative medicine without any guidelines for treatment of serious chronic diseases not even to invigorate themselves. It is, therefore, suggested that medical doctors or scientists verify the true effects or side-effects from the most common complementary or alternative therapies through experiments. Also medical doctors should provide a comfortable atmosphere for discussion among doctors and patients who would like to try these therapies.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.34 no.3
• /
• pp.220-225
• /
• 2014

Generally, the nonlinearity of ultrasonic waves is measured using a nonlinear parameter ${\beta}$, which is defined as the ratio of the second harmonic's magnitude to the power of the fundamental frequency component after the ultrasonic wave propagates through a material. Nonlinear parameter ${\beta}$ is recognized as an effective parameter for evaluating material degradation. In this paper, we evaluated the nonlinear parameter of Al6061-T6 which had been subjected to an artificial aging heat treatment. The measurement was using the transmitted signal obtained from contact-type transducers. After the ultrasonic test, a micro Vickers hardness test was conducted. From the result of the ultrasonic nonlinear parameter, the microstructural changes resulting from the heat treatment were estimated and the hardness test proved that these estimates were reasonable. Experimental results showed a correlation between the ultrasonic nonlinear parameter and microstructural changes produced by precipitation behavior in the material. These results suggest that the evaluation of mechanical properties using ultrasonic nonlinear parameter ${\beta}$ can be used to monitor variations in the mechanical hardness of aluminum alloys in response to an artificial aging heat-treatment.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.5
• /
• pp.20-32
• /
• 2008

Runoff characteristics of the Oedocheon in Jeju island were investigated using the long-term stream stage monitoring data. At the Cheonah valley in the upstream area and Oedocheon downstream, annual runoff occurred 21 and 12 times, respectively, and their average runoff periods were 21 days and 12 days, respectively. Stream stage response time to rainfall was 4 hours, and storm-water transfer from the upstream, Cheonah valley, to the Oedocheon downstream took about 2 hours. The stream discharge measurements had been carried out from Feb. 2004 to Jul. 2005, and showed that normal discharge of the Oedocheon was 0.39 $m^3$/sec in average. Stage-discharge curves were developed to estimate base flow (normal discharge) and (direct) surface runoff. The base flow separations by a numerical filtering technique illustrated that annual surface runoff and base flow accounted respectively for 31.8${\sim}$36.5%, 63.5${\sim}$68.2% of the total stream discharge.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.12 s.159
• /
• pp.1649-1660
• /
• 2006

IIn the United States, professional dress codes for working women have changed over time since the 1970s. Considering the changes, from conservative and traditional business uniforms in the 1970s, business casual in the late 1980s through 1990s, and the current revival of tailored business suits, this study investigated working women's business jacket practices and their association with personal, psycho-social, and physical characteristics. Working women's job satisfaction and corporate culture were also examined in relation to business jacket practices. Research data were collected by implementing mail surveys to 1,500 randomly selected working women in the United States. Of the 1,500 distributed questionnaires, a total of 312 were returned, of which 265 were deemed usable, yielding a 20.8% response rate. For data analysis, descriptive statistics, such as frequency, percentage distribution, mean scores, standard deviations, and Canonical Correlation were tabulated. The respondents ranged in age from 22 to 65. The mean age of the respondents was 44 years(SD=9.63). Most respondents were married(77.4%), working full-time(81.4%), career-oriented (77.2%), Caucasian(89.8%), had at least one child(78.9%), and had a professional job(75.9%). Working women's age, number of children, self-confidence in dressing, perceived importance of clothing, body frame size, and visibility to superiors and public were positively associated with business jacket practices, while age of first child, family size, dress size, and job satisfaction were negatively associated with business jacket practices.

• The Korean Journal of Physiology
• /
• v.26 no.2
• /
• pp.159-166
• /
• 1992

The present study was designed to evaluate effects of intermittent electrical stimulation of the sciatic nerve on the atrophic response of antigravity muscles, such as the soleus (slow m.) and medial gastrocnemius (fast m.) muscles. Rats (Sprague-Dawley, 245-255g) were subjected to a hindlimb suspension and divided into three groups : one was with hindlimb suspension (MS) and another with hindlimb suspension plus intermittent electrical stimulation of the sciatic nerve (HS ES). Control group (CONT) was kept free without strain of the hindlimb. After 7 days of hindlimb suspension, the soleus and medial gastrocnemius muscles were cut at their insertion sites, and were then connected to the force transducer to observe their mechanical properties. Optimal pulse width and frequency of electrical stimulation were 0.2ms, 20Hz for the soleus muscle and 0.3ms, 40Hz for the medial gastrocnemius muscle under supramaximal stimulation. Body weight and circumference of the hindlimb were significantly decreased in HS and HS-ES groups compared with the control group. In HS-ES group, however, the weight of the soleus muscle was not different from that in the control group while the weight of the medial gastrocnemius muscle was lower than that in the control group. In HS group, mechanical properties of muscle contraction including contraction time, half relaxation time, twitch tension, tetanic tension, and fatigue index of both muscles were significantly decreased compared with the control group except for twitch tension and tetanic tension of medial gastrocnemius muscle. The degree of atrophy of the soleus muscle in HS group was more prominent than that of the medial gastrocnemius muscle. Twitch tension and fatigue index of the soleus muscle and fatigue index of the medial gastrocnemius muscle in HS-ES group were not different from those of the control group. While mechanical properties of the soleus muscle examined were all significantly increased in HS-ES group compared with HS group, only contraction time and fatigue index of the medial gastrocnemius muscle were significantly increased in HS-ES group. These data indicate that intermittent electrical stimulation may be useful in prevention of muscle atrophy.

• Korean Journal of Psychosomatic Medicine
• /
• v.13 no.2
• /
• pp.85-94
• /
• 2005

Objectives: This prospective and open-label study was conducted to evaluate the efficacy and safety of quetiapine and haloperidol in patients with delirium. Methods : Fourty patients(19 patients in a quetiapine group : 21 patients in a haloperidol group) with delirium by DSM-IV were treated with flexible doses of open-label qvetiapine and haloperidol. To evaluate the primary efficacy of the medication, scores from the Korean version of Delirium Rating Scale(K-DRS) were assessed every seven days and to evaluate the secondary efficacy and safety, scores from the Clinical Global Impression-Severity, Korean Version of Mini-Mental State Examination, and the Drug-Induced Extrapyramidal Symptoms Scale were assessed at the baseline and the seventh day. Data were gathered from November 2004 to June 2005. Results : K-DRS scores for each group decreased significantly over the study period; however, no significant differences between groups were found. The group-by-time effect was not significant. In addition, there was no significant difference in the frequency of response to drugs between the two groups. No patients reported clinically significant side effects. Conclusion : These data show no significant difference in the efficacy and safety between quetiapine and haloperidol in the treatment of delirium. Since haloperidol has a great possibility of causing a extrapyramidal side effect resulted by previous studies, it is expected that quetiapine, a renowned medication with low side effects, may be a useful alternative agent to haloperidol, the classical antipsy-chotics, in the treatment of delirium.

• Science of Emotion and Sensibility
• /
• v.14 no.2
• /
• pp.269-278
• /
• 2011

This paper illustrates the inter-relationship between the theta/alpha ratio of the EEG signal and multiple HRV related parameters associated with the cardiovascular system response during event-related stimuli. Both EEG and PPG signals were simultaneously recorded in 21 healthy subjects. All subjects had their attention focused on the CNT program for nine minutes. Time-frequency analysis was applied to the EEG and PPG signals. The theta/alpha ratio was extracted from the EEG results, and the HRV features, including beat interval(1), SDNN(2), RMSSD(3), NN50(4), LF(5), HF(6), and LFIHF(7), were extracted from the PPG. Through multiple linear regression, the relationship ($R^2$) between the multiple combined features and the theta/alpha rhythm was identified. As a result, the combinations of $R^2$($R^2=0.253$; seven dimensions) and the theta/alpha ratio indicated a higher inter-relationship value than those of other combinations. The combinations of features that were greater than three dimensions, based on {SDNN(2), HF(6)}, generally showed higher $R^2$ value. We demonstrate that the high dimensional combinations had a higher correlation than did the low dimensional combinations.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.22 no.4
• /
• pp.75-82
• /
• 1986

A field experiment was carried out to clarify the effect of underwater sound on the luring of fish school. The effects of. the acoustic emission on the luring of fish school were checked actually at a set net fishing site in Namhae using a commercial acoustic equipment, Dairyo-8. An emitting system of sound was designed by the authors, and the ambient noise, the sound pressure level and the reaction of fish school were measured in the set net. 1. The predominent frequency band of ambient noise was 150Hz-400Hz,.and the sound emitted was 400Hz-100Hz. The sound pressure level of ambient noise in set net was higher at the landing part, and lower at the playgrond, the gate of court and "the enterance of inclined "passage. The ambient noise was increased with the time elapse-d at the stage of hauling net, but :it was decreased suddenly at the final stage due probably to the decrease of the swimming speed of the fish school. 2. The results of the observation and the recording paper of echo sounder indicate that the effect of emitting sound in the bag net of set net was remarkable for the luring of fish school in the early stage, but decreased after 30 minutes. The reaction of fish school is more sensitiv2 to the sound pressure level than the time intervals between the emission and the pause. For the purpos~ of practical use, it is nesessary to confirm what kind of sound pressure level is the best for the luring of fish school. 3. In response to the acoustic equipment(Dairyo-8), fish school started to swarm 20 minutes after the sound emission and scattered when the sound paused. As the emitting pattern of the acoustic equiment, the three seconds of emission after one second of pause was more effective than the continuous emission at the set net fishing ground. Catch of the fish(s during th~ sound ernissio:l at the gate of court was three to five times more than that of no emission.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.25 no.2
• /
• pp.119-124
• /
• 2005

This study was conducted from March 21 to July 8 in 2004 at JeJu Island to investigate the influences of split nitrogen application times on creeping bentgrass vegetation. Nitrogen rate was 20 kg/10a and it was applied from once to 5 times. The result obtained were summarized as follows; plant height was getting longer as nitrogen was split applied from once to 5 times. So it was longest at 5 times split nitrogen application, but it was no significance from 4 to 5 times. Root length, Minolta SPAD-502 chlorophyll meter reading value, leave and root weight n[e directly proportional plant height response. Degree of land cover Iud density of creeping bentgrass increased as nitrogen was split applied from once to 5 times. But degree of land cover md density of reed decreased. The number of reed species on decreased as nitrogen was split applied from once to 5 times. Then ranking of the dominant weeds were Portulaca oleracea Polygonum hydropiper and Stellaria media (at once split time nitrogen application), Portulaca oleracea, Polygonum hydropiper and Digitaria adscendens (at 2 split times nitrogen application), Digitaria adscendens and Portulaca oleracea Polygonum hydropiper, (at 3 split times nitrogen application), Portulaca oleracea, Poa annua and Polygonum hydropiper (at 4 md 5 split times nitrogen application). These results indicate that the optimum frequency of split N applications is four times for growth of creeping bentgrass in volcanic ash soils of Jeju island.