• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.8
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• pp.27-35
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• 1999

A radius of ring resonator is determined by the resonant frequency. Resonant frequencies of resonators with the circumference which is integer times of wave length are not same the expected. In this paper, we suggest the design method of a ring resonator with coupling gap, which has the resonant frequency of desire. The equation which can make reduction of the radius of the resonators depending on the gap space is derived by the method of transmission line analysis. The criterion is suggested to determine the radius of the resonator in accordance with relative permittivity. A ring resonator by the proposed method is as small as one-third of basic ring in size and it has the resonant frequency of desire. T-type coupling line is designed to obtain large attenuation of $S_{11}$ at pass-band. These coupling line capacitances are very lower than the gap capacitances, it does not affect the resonant frequency.

• Annals of Clinical Neurophysiology
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• v.5 no.1
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• pp.16-20
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• 2003

Background: Mobile phone has become a very popular device used in everyday our lives. However, the possible hazard to human body such as brain tumor has been proposed intermittently. This unwanted possibility was calmed down due to the absence of definite evidence of hazard. This study was performed to see the effect of mobile phone use on the brain temperature. Methods: In 20 volunteers, we performed 4 steps of temperature measuring procedure. Four steps are pre-use (S1, basal state), wire-phone (S2, conventional telephone), PCS phone (S3, using 1,750~1,900 MHz), cellular phone (S4, using 820 MHz) states. Brain temperatures were measured by radiothermometer at 10 sites (5 sites in each hemisphere) of the brain after 5minutes of telecommunication through the phones. The final data were compared using paired t-test. Results: In PCS phone user group (Average; $35.73708^{\circ}C$), brain temperature decreased (with statistical significance, p<0.05), compared to those of non-user group (Average; $35.9527^{\circ}C$) or conventional wire phone user group. In cellular phone user group (Average; $35.82155^{\circ}C$), brain temperature decreased slightly (without statistical significance, p>0.05) compared to those of non-user group (Average; $35.9527^{\circ}C$) or conventional wire phone user group (Average; $35.922^{\circ}C$). The temperature change was not limited to the mobile phone applied side but on both hemisphere of the brain. Conclusion: In conclusion, mobile phone (especially PCS phone) decreased brain temperature in both hemispheres without side-to-side temperature difference. In addition, this study suggests possibility of radiothermometer application to the study of electromagnetic wave effect and protection method research in the future.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.4
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• pp.89-98
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• 2012

The purpose of this study is to female child Han-bok reform design for body growth. Nowadays there is common the western style daily life and special day instead of traditional style Han-bok in Korea. So the decrease in the use of Han-bok have being appeared. Specially, Children's Han-bok undesirable clothes for economic, environment, and resources because of their rapid growth and changing trend. Therefor, they do away with used Han-bok without next buying of school age. Children's parents and children are decision together purchase of children's Han-bok on-line for pleasure and economic reasons on pre-school or 1st year student for their tradition-education class. After 2000year, children's Han-bok pup-up on e-market because of the fashion focus on tradition and Korean wave for parody of Korean drama. Flowing the Research of 2010 Size Korea, the elementary school age child height growth 6cm per year, the sleeve length are 3cm growth. But Chi-ma(a pice of Han-bok) from e-market, has only 5cm margin on shoulder and no margin on Jegori(a pice of Han-bok) shoulder and sleeve, reason of that the children can't wear next year. Therefor this study is development female child Han-bok reform design for body growth, for extend to wear Han-bok on school age children and flow tradition custom of Cho-sun Dynasty's clothing custom for boost tradition conscious and reduce of cloth waste for environment.

• Journal of Families and Better Life
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• v.33 no.2
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• pp.89-101
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• 2015

This study examined the effects of self-differentiation and psychological discomfort on antenatal attachment of pregnant couples in their third trimester of pregnancy. The subjects were 182 couples in J province who had participated in the first wave of the Korea Attachment Longitudinal Study (KALS). Data were analyzed by means of frequency, percentages, Pearson's correlations, and stepwise multiple regression models using SPSS 20.0. The findings were as follows. First, the independent t-test showed that the mean scores of pregnant women's self-differentiation were lower than their spouses in all subscales except emotional cutoff, and higher than in all psychological discomfort subscales. There was no significant difference in antenatal attachment quality between women and men, but the pregnant women significantly spent more time thinking about the fetus than their spouses. Second, the stepwise multiple regression models revealed that pregnant women's emotional cutoff in self-differentiation influenced the most on both quality and quantity of antenatal attachment. Among subscales of their spouses' self-differentiation, only emotional reactivity had an impact on quality of antenatal attachment, and fusion with others had the most impact on quantity of antenatal attachment. Among the pregnant women's and their spouses' psychological discomfort subscales, only depression influenced each quality and quantity of antenatal attachment. This is the very first and only study in which the impact of the pregnant couples' self-differentiation on antenatal attachment has been examined.

• Journal of applied mathematics & informatics
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• v.11 no.1_2
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• pp.305-316
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• 2003

Recently, an iterative algorithm for finding the interior eigenvalues of a definite matrix by CG-type method has been proposed. This method compares to the inverse power method. The given matrices A, and B are assumed to be large and sparse, and SPD( Symmetric Positive Definite) The CG scheme for the optimization of the Rayleigh quotient has been proven a very attractive and promising technique for large sparse eigenproblems for smallest eigenvalue. Also, it is very amenable to parallel computations, like the CG method for the linear systems. A proper choice of the preconditioner significantly improves the convergence of the CG scheme. But for parallel computations we need to find an efficient parallel preconditioner. Our candidates we ILU(0) in the wave-front order, ILU(0) in the multi-coloring order, Point-SSOR(Symmetric Successive Overrelaxation), and Multi-Color Block SSOR preconditioner. Wavefront order is a simple way to increase parallelism in the natural order, and Multi-coloring realizes a parallelism of order(N), where N is the order of the matrix. Another choice is the Multi-Color Block SSOR(Symmetric Successive OverRelaxation) preconditioning. Block SSOR is a symmetric preconditioner which is expected to minimize the interprocessor communication due to the blocking. We implemented the results on the CRAY-T3E with 128 nodes. The MPI (Message Passing Interface) library was adopted for the interprocessor communications. The test problem was drawn from the discretizations of partial differential equations by finite difference methods. The results show that for small number of processors Multi-Color ILU(0) has the best performance, while for large number of processors Multi-Color Block SSOR performs the best.

• Bulletin of the Society of Naval Architects of Korea
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• v.2 no.1
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• pp.9-14
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• 1965

Ship designers make every efforts to get faster ships in accordance with the development of the Naval Architecture. But for the speed lying over factor length ratio 2.5-3.0, we could put a powerful engine into the conventional round bottom displacement type vessels, but it is very difficult in view point of economy, weight and volume. The principal cause of these speed obstacles is the wave making resistance and researchers are trying to decrease this resistance. One of the resolving ways, planing hulls were applied to small high boats. Planing hull's advantage is not restricted to speed, but the workmanship of the planing hull is easier than those of displacement type vessels of round bottom. Planing hull, therefore, are widely applicable to the intermediate speed boats, which don't have enough high speed to take planing advantage, as well as high speed boats. We will discuss related phenomena of the planing hull in details and this paper we particularly interested in the interjection point(speed length ratio 3.0-3.5 by Mr. D. De Groots) between semi-planing and full planing hulls on the resistance characteristic curve. The paper by Prof. Keuck Chun Kim, "Some Characteristics of Straight Framed V-bottom Hull Forms", Journal of the society of Naval Architects of Korea, Vol.1, No.1, Dec.5, 1964, is referred to the V-bottom hull forms belonging to low speed region and determines practical applicable limit of the speed length ratio combined with construction costs, under which are still used by large commercial vessels. This is the interesting contrast between his and authors. We will further discuss the speed length ratio which is considered as a beginning point to planing effect. For this analysis, we choose 3 model ships: Model (1) and (2) have the same principal dimensions, model 3 varied dimension. Model (1) is full-planing hull, (2) is semi-planing hull and (3) is complete planing hull. They are aimed to collect proper design data for purposed ships.

• Journal of the Korea Society of Computer and Information
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• v.21 no.12
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• pp.157-163
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• 2016

Purpose : This study purposed on the understanding of psychology in the elderly women using depression scale and electroephalography. The subjects were thirty elderly women in geriatric care hospital. All participants were elderly women over 65 years old. The subjects signed up with informed consent and they were divided into a normal elderly group, an exercise elderly group and a hospital elderly group. They were randomly assigned with 10 persons. Methods : The study instruments were Geriatric Depression Scale(GDS) and Poly-G-I. Brain wave activity was measured by 'power spectrum analysis' of TeleScan program. Statistic analysis consisted of average, standard deviation, One-way ANOVA and post-hoc Tukey using SPSS 21.0 version. The significance was set at .05. Results : Depression scale results showed that the exercise elderly group were $10.60{\pm}5.36$ points which was the lowest among the three groups. The Normal elderly group was $16.20{\pm}5.59$, and the hospitalized elderly group was $16.70{\pm}6.76$ points. There was no significant difference between the normal elderly group, exercise elderly group and hospitalized elderly group. The hospitalized group showed statistical difference in relative theta power in the area of Fp1, F3, F4, T3, P3 as compared to the normal elderly group and the exercise elderly groups. There was no significant difference between relative beta power and relative gamma power in three groups. Conclusion : Geriatric depressed scale showed no significant difference in each group. This is indicated in the mental problems associated with depression. This indicates a higher level of depression in the hospitalized elderly women, more than in the normal elderly women and exercise elderly women groups.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.4 no.1
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• pp.29-34
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• 2010

The fully implantable hearing devices (FIHDs) have been studied to compensate the defect of conventional hearing aids. Typically, a microphone for FIHDs was implanted under the skin of the temporal bone. So, implantable microphone characteristics can be affected by the eating food, chattering teeth and moving artifact. In this paper, we fabricated the physical model that was similar to characteristics of human temporal bone and skin, and we measured implanted microphone sensitivity for effect of bone conducted noise signal. For the measurement of microphone sensitivity, we applied 1 kHz pure sounds that were transmitted to implanted microphone and sine wave vibrations of varied frequency were simultaneously transmitted through the artificial bone. As a result, sensitivity of implanted microphone can be modified by bone conducted signal and this phenomenon was confirmed at varied frequency band.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.44-48
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• 2007

In recent years, the size of plane substrates and semiconductor wafers has increased. As conventional contact transportation systems composed of, for example, carrier rollers, belt conveyers, and robot hands carry these longer and wider substrates, the increased weight results in increased potential for fracture. A noncontact transportation system is required to solve this problem. We propose a new noncontact transportation system combining acoustic viscous and aerostatic forces to provide damage-free transport. In this system, substrates are supported by aerostatic force and transported by acoustic viscous streaming induced by traveling wave deformation of a disk-type stator. A ring-type piezoelectric transducer bonded on the stator excites vibration. A stator with a high Q piezoelectric transducer can generate traveling vibrations with amplitude of $3.2{\mu}m$. Prior to constructing a carrying road for substrates, we clarified the basic properties of this technique and stator vibration characteristics experimentally. We constructed the experimental equipment using a rotational disk with a 95-mm diameter. Electric power was 70 W at an input voltage of 200 Vpp. A rotational torque of $8.5\times10^{-5}Nm$ was obtained when clearance between the stator and disk was $120{\mu}m$. Finally, we constructed a noncontact transport apparatus for polycrystalline silicon wafers $(150(W)\times150(L)\times0.3(t))$, producing a carrying speed of 59.2 mm/s at a clearance of 0.3 mm between the stator and wafer. The carrying force when four stators acted on the wafer was $2\times10^{-3}N$. Thus, the new noncontact transportation system was demonstrated to be effective.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.751-758
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• 2002

Boreholes that are drilled in soft or unconsolidated materials such as gravels and coals are prone to collapse. To maintain the hole, some kinds of casing pipes are needed. If thereby a plastic pipe e.g. PVC is used for the casing, Televiewer tool is still capable of detecting structural features such as fractures in the borehole wall behind the pipe, whereas other borehole-imaging logging devices such as BIPS (Borehole Image Processing System) and FMS(Formation Micro Scanner) won't provide any information about that. Televiewer's primary component is a piezoelectric transducer centered in the hole. It acts as both a transmitter and receiver, and sends an ultrasonic beam. That is reflected, in the same manner as the seismic wave propagation, from the both sides(inner and outer surfaces) of the casing pipe, transmits through the pipe and then reflected from the borehole wall. With an appropriate choice of time-windowing, it is possible to capture the returning signals from both the borehole wall and the outer side of casing pipe as well. A suite of laboratory tests were performed on various physical models composed of plastic pipes with different diameters. Although the amplitudes of returning signals were reduced to about half the usual value due to the transmission loss, the dynamic range of Televiewer tool was sufficient to observe the structural features behind the casing pipe. Besides, several representative case studies at various research areas in our country are presented. The results demonstrate the usefulness of the transmissivity of Televiewer acoustic km, which will assist in further structural interpretation.