• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.6
• /
• pp.95-104
• /
• 2003

The electric traction systems are quite differ from general power systems which is single-phase and heavy load. Therefore, there are inevitably power quality problems such as steady state or transient voltage drop, voltage imbalance and harmonic distortion. Among these problems, since steady-state volatge drop is the one of most important factor in electric power quality, many researches about on the compensation of volatge drop by using SVC(Static Var Compensator) and/or STACOM(Static Compensator) have been studied and proposed Also, it is expected that transient voltage drop(voltage sag) could affect the control and safety of high speed traction load. In this paper, voltage sag compensation of AT(Auto Transformer) feeding system are studied The detailed transient models of utility source, scott transformer, AT, and traction load are estabilished. The application of DVR(Dynamic Voltage Restorer) in electric traction system is proposed to compensate the voltage sag of traction network which is occured by the fault of utility source. It can be shown that application of the DVR in electric traction system is very useful to compensate the volatge sag from the result of related simulation works.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.3
• /
• pp.103-108
• /
• 2016

In daily life, humans get stress very often. Stress is one of the important factors of healthy life and closely related to the quality of life. Too much stress is known to cause hormone imbalance of our body, and it is observed by the brain and bio signals. Based on this, the relationship between brain signal and stress is explored, and brain signal based stress index is proposed in our work. In this study, an EEG measurement device with 32 channels is adopted. However, only two channels (FP1, FP2) are used to this study considering the applicability of the proposed method in real enveironment, and to compare it with the commercial 2 channel EEG device. Frequency domain features are power of each frequency bands, subtraction, addition, or division by each frequency bands. Features in time domain are hurst exponent, correlation dimension, lyapunov exponent, etc. Total 6 subjects are participated in this experiment with English sentence reading task given. Among several candidate features, ${\frac{{\theta}\;power}{mid\;{\beta}\;power}}$ shows the best test performance (70.8%). For future work, we will confirm the results is consistent in low price EEG device.

• Child Health Nursing Research
• /
• v.2 no.1
• /
• pp.13-26
• /
• 1996

This descriptive study was done to detect the possibilities of the development of the advocacy concept in nursing. The subjects consisted of 3 nurses who had agreed to participate to the study, working at nursery room in a general hospital. Data was collected from May 22 to June 13 in 1995 through tape recorded intensive-interview, and written down, then content analyzed qualitatively related to the infant advocacy. 1. Derivation fo the meaning about advocacy concept 1) The situations in need of infant advocacy were 12 categories : malpractice, overcharing, negligence, unnecessary services, and services without consent, and so on. 2) Fourteen categories of advocacy activities percived by nurses were derived from participants' statements. Protesting infant or his /her families against their counterpart, providing informations to families, cooperating with medical staffs for her patient, then calling medical staff not so as to be maleficient to her patient in its rank. 3) The expected result of advocacy activities perceived by nurses was respectively positive to her patient or families, but negative to nurse. 4) The feelings of nurses in the sitution of advocacy were expressed in to concern, comprehension, regret, powerlessness, charity, desire, and so on. 5) Nurses perceived that advocacy activities could be influenced positively by factors related to nurses' qualification and negatively by factors related to doctor's overdo and nurse's underdo. 2. Categorization of the meaning and their relationships In case of antecedental situation in need of infant advocacy, nurse perceives her patients need the advocacy to get a benefit through nurse's information, intervention speaking, building cooperations. The expected factors to influence advocacy activities perceived by nurses, are the power imbalance between medical staffs, the nurse's qualification, and the nurse's feeling from the situation. The above results suggest that the infant care situation will be recommendable field work place for concept development of advocacy with hybride model when it involves infant's families.

• Fashion & Textile Research Journal
• /
• v.9 no.1
• /
• pp.15-23
• /
• 2007

In the Middle Ages it was customary to cover up the hair, but the Renaissance brought uncovered coiffures with the revival of humanism. In those days, silk and linen veil, ribbon, string of pearl used for covering, wrapping round with the hair. During the Baroque period, the style of hair was to pursue the beauty of imbalance in form, reflecting the atmosphere of the time. Hurluberlu and Fontanges hairstyles were in fashion. Then in the Rococo period, huge, resplendent coiffures of exquisite beauty were invented as a symbol of power, and these modes of hairdo were a dominant force in the culture of personal adornment of that time. Pouf and enfant hairstyles were in fashion. As a reaction against the extravagance of the proceding modes, late 18th and early 19th centuries brought revival of simpler hairstyles of ancient Greece and Rome by the influence of neoclassicism. The latter half of the 1820's onwards saw he reappearance of voluminous coiffures as well as an enormous variation of knots with combinations of false knots and chignons. Late 19th through early 20th centuries was the period of beautifully waved hair, the style of which was an integration of Marcel waves and Art Nouveau. The 20th century saw the epoch-making invention of permanent waves using electricity. Concurrently, with an increasing participation of women in social affairs since pre-and post-World War I periods, as well as with Art Deco in full flourish, bobbed hair was created in pursuit of lightness and nimbleness, quickly showing the change of women's modes of life. Hair fashions thoroughly embody the aesthetic sense of each period, reflecting the landscape of contemporary society.

• The Journal of Internal Korean Medicine
• /
• v.26 no.4
• /
• pp.844-852
• /
• 2005

Objectives : Through spectral analysis of heart rate variability(HRV) to study autonomic nervous system dysfunction of Hwabyung, culture related disease in Korea. Methods : HRV of 18 patients diagnosed as Hwabyung was measured against 13 healthy controls. HRV was measured by SA-2000p(Mediocre, Korea) for five minutes after 5 minutes resting. Results : 1. In time domain analysis, mean pulse rate(PRT) of in Hwabyung group was significantly higher than healthy controls. Standard deviation of all normal P-P intervals(SDNN), the square root of the mean of the sum of the squares of differences between adjacent normal P-P intervals(RMS-SD) in Hwabyung group was lower than healthy controls, but not significant. 2. As for frequency domain analysis, In TP(logarithmic total power), In VLF(logarithmic very low frequency), and In LF(logarithmic low frequency )in Hwabyung group was significantly lower than healthy controls. Ln HF(logarithmic high frequency), LF/HF ratio in Hwabyung group was also lower but not significant. Conclusions : This study suggests tile activity and imbalance of cardiac autonomous nervous system in Hwabyung patient is significantly lower than healthy individuals.

• The Korean Journal of Applied Statistics
• /
• v.23 no.6
• /
• pp.1047-1056
• /
• 2010

In clinical trials, patients should be randomly allocated to treatment and control groups that consider the balance of their prognostic factors(covariates). There are many randomization methods and stratification is popular in Korea. In stratification, patients are divided into strata based on covariates and then the patients are randomly assigned to the arms of each strata. If the number of covariates increases then the number of strata increases rapidly and the results may not be reliable when the patients are inadequate in each strata. To complement this problem Pocock and Simon (1975) suggested a new randomization method that called for minimization focusing on the balance of covariates. In this study, we compare the advantages and disadvantages, the imbalance of covariates, the power of minimization, and other randomization methods by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.6
• /
• pp.1307-1312
• /
• 2015

As smart-phones become popular, mobile data traffic has been dramatically increasing and intensive researches on the next-generation mobile communication network is in progress to meet the increasing demand for mobile data traffic. In particular, heterogeneous network (HetNet) is attracting much interest because it can significantly enhance the network capacity by increasing the spatial reuse with macro and small cells. In the HetNet, we have several problems such as load imbalance and interference because of the difference in transmit power between macro and small cells and cell range expansion (CRE) can mitigate the problems. In this paper, we propose a new cell selection scheme with adaptive cell range expansion bias (CREB) for ultra dense HetNet and we analyze the performance of the proposed scheme in terms of average cell transmission rate through system-level simulations and compare it with those of other schemes.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.24 no.3
• /
• pp.109-115
• /
• 2011

Objectives: To characterize autonomic dysfunction in patients with Cold hypersensitivity, their heart rate variability(HRV) were measured and analyzed with cold hypersensitivity patients, compared with those of normal population. Methods: We studied 56 patients visiting Gangnam Kyung-hee korean hospital from 1st January 2010 to 31th December 2010. Heart rate variability were obtained from 28 female patients who suffer from cold hypersensitivity and 28 healthy female controls in resting state. We studied the difference of Heart rate variability between two groups by Independent T-test using SPSS for windows(version 17.0). Results: Standard deviation of NN interval(SDNN), total power(TP), Very low frequency(VLF) in patients with cold hypersensitivity were significantly different with those of controls. While no significant differences were observed in square root of mean squared differences of successive NN intervals (RMSSD), low frequency (LF) and high frequency(HF). Conclusions: The decreased values of heart rate variability(HRV) study means that they may have some kinds of imbalance in autonomic nervous system in cold hypersensitivity patients. heart rate variabiliry(HRV) study might be a tool of diagnosis and predictors in cold hypersensitivity patients.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.63-66
• /
• 2015

As smart-phones become popular, mobile data traffic has been dramatically increasing and intensive researches on the next-generation mobile communication network is in progress to meet the increasing demand for mobile data traffic. In particular, heterogeneous network (HetNet) is attracting much interest because it can significantly enhance the network capacity by increasing the spatial resue with macro and small cells. In the HetNet, we have several problems such as load imbalance and interference because of the difference in transmit power between macro and small cells and cell range expansion (CRE) can mitigate the problems. In this paper, we propose a new cell selection scheme with adaptive cell range expansion bias (CREB) for ultra dense HetNet and we analyze the performance of the proposed scheme in terms of average cell transmission rate through system-level simulations and compare it with those of other schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.4
• /
• pp.40-48
• /
• 2007

MANET constructs a network that is free and independent between sensor nodes without infrastructure. Also, there are a lot of difficulties to manage data process, control etc.. back efficiently from change of topology by transfer of sensor node that compose network. Especially, because each sensor node must consider mobility certainly, problem about energy use happens. To solve these problem, mechanisms that compose cluster of cluster header and hierarchic structure between member were suggested. However, accompanies inefficient energy consumption because sensing power level of sensor node is fixed and brings energy imbalance of sensor network and shortening of survival time. In this paper, I suggested intelligent clustering mechanism for efficient energy management to solve these problem of existent Clustering mechanism. Proposed mechanism corresponds fast in network topology change by transfer of sensor node, and compares in existent mechanism in circumstance that require serial sensing and brings elevation survival time of sensor node.Please put the abstract of paper here.