• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.1-10
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• 2013

In this paper, a broadband planar monopole antenna for multi-band services is proposed. The physical size of the proposed antenna is miniaturized by folding a rectangular loop. And a resonance point in the 3.9 GHz band is reduced by a coupling phenomenon with the central part of the T-shaped patch and the folded rectangular loop. In addition, the T-shaped patch is inserted to the rectangular shaped monopole antenna due to deriving the broadband frequency characteristics. The frequency characteristic is optimized by adjusting the gap and length of the folded rectangular loops and a transverse diameter of the T-shaped patch. The antenna dimensions including the ground plane are $40{\times}60{\times}1.6mm^3$. It is fabricated on the FR-4 substrate(${\epsilon}_r$=4.4) using a microstrip line of $50{\Omega}$ for impedance matching. In the measured result, the bandwidth corresponding to the VSWR of 2:1 is 162 MHz(815~977 MHz) and 2,530 MHz(1.43~3.96 GHz). For analyzing the human effect by the proposed antenna, 1 g and 10 g averaged SARs are simulated and measured. As the simulated results, 1 g-averaged SAR is 1.044 W/kg, and 10 g-averaged SAR is 0.718 W/kg. This result are satisfied by the SAR guidelines which are 1.6 W/kg(1 g-averaged) and 2.0 W/kg(10 g-averaged).

• Journal of the Korean Magnetics Society
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• v.16 no.6
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• pp.300-304
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• 2006

The varied heating temperatures were used for magnetic core materials, which nano sized ${\alpha}-Fe$ crystalline was created in nanocrystalline Fe-Si-B-Nb-Cu materials, with hish permeability and low power loss. The highest permeability and lowest power loss were obtained to the specimen heat-treated at $510^{\circ}C$. The signal transmission characteristics of inductive coupler, which was manufactured by using the magnetic core materials prepared in this study, at low frequency range, was influenced strongly by magnetic property of magnetic core materials as this result is corresponding to the permeability as a function of heat treatment temperature, as well, it was improved by impedance matching at high frequency range. Over $500{\mu}m$ of air gap in coupler is required to maintain the magnetic properties without magnetic saturation on the subterranean line transferred hish current of 300 A. The inductive coupler for PLC, which has an attenuation characteristics of less than 5dB, was manufactured using nano-crystalline magnetic core materials through the above mentioned research results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5214-5218
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• 2011

In this paper, bandwidth improvement of a series-fed two dipole array(STDA) antenna applicable for mobile communication base station antennas is studied. The proposed STDA antenna consists of two strip dipole antennas with different lengths which are connected directly trough a coplanar stripline(CPS). By adjusting the spacing between the two dipoles and the length of the second dipole, the bandwidth of the STDA can be enhanced. In addition, an integrated balun composed of a short-circuited microstrip line and a slot line is utilized to minimize the area required for a feeding part, and a broadband impedance matching is obtained by adjusting the feeding point. Based on the proposed antenna structure, an STDA antenna covering the frequency band ranging from 1.75 GHz to 2.7 GHz, which includes almost all the existing mobile communication frequency bands, with more than 5 dBi gain is designed and fabricated on an FR4 substrate with dielectric constant of 4.4 and thickness of 1.6mm, and experimentally tested. The fabricated antenna shows impedance bandwidth of 49%(1.7-2.8 GHz) for VSWR<2, a gain higher than 5.5 dBi, and a front-back ratio better than 12 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12B
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• pp.1452-1458
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• 2009

In this paper, Our proposed Multipurpose Complex Card UHF band RFID small-size Tag antenna. Multi purpose Complex Card UHF band RFID small-size Tag antenna that is to minimize the low efficiency of RFID Tag Read Range that generates space limitation and a conductor surrounded by inducing fingerpring system with dual(HF, UHF) Card is presented. Our proposed UHF band RFID small-size Tag antenna is for the Multipurpose Complex Card that is mounted on the fingerpring system as well as the HF Tag. It also enables to minimize and facilitates Tag chip matching by adjusting Tapered, Meander line and Loop structure. Given the card substance properties and periphery circuit, the proposed small-size Tag antenna, in this report, is designed with PET film with size of $50{\times}15mm^2$. The RFID small-size Tag method for measurements is used by EPCglobal Static Test instrument in Anechoic Chamber, which is tested with dual Card, within the car and in wallet. It is found that Read Range is 3.8m from the EPCglobal Static Test, Maximum Read Range within the car from the field test results in 7.6m. Proposed Tag antenna is will be used in the parking control security system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1916-1923
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• 2007

We have studied to obtain the SAW filter for the passband was formed on the Langasite substrate and was evaporated by Aluminum-Copper alloy and thin we performed computer-simulated by simulator. We cm fabricate that the block weighted type IDT as an input transducer of the filter and the withdrawal weighted type IDT as an output transducer of the filter from the results of our computer-simulation. Also, we have performed to obtain the properly design conditions about phase shift of the SAW filter for WCDMA. We have employed that the number of pairs of the input and output IDT are 50 pairs and the thickness and the width of reflector are $5000\;{\AA}$ and $3.6{\mu}m$ respectively. And we have employed that the distances from the hot electrode to the reflector are $2.0{\mu}m$, $2.4{\mu}m$ and the distance from the hot electrode to the ground is $1.5{\mu}m$ respectively. Frequency response of the fabricated SAW filter has the property that the center frequency is about 190MHz and bandwidth at the 3dB is probably 7,8MHz. And we could obtain that return loss is less then -18dB, ripple characteristics is probably 3dB and triple transit echo is less then -25dB after when we have matched impedance.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.334-346
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• 2007

The present study examined the reproductive factors and food intake pattern which influence on the breast cancer risk in Daegu${\cdot}$Gyungbuk area. The case subjects were 103 patients newly diagnosed as breast cancer at Kyungpook National University Hospital. The control subjects were 159 healthy women selected by frequency matching of age and menopausal status in the same community. The survey was conducted by individual interviews using questionnaires which include general and reproductive characteristics, dietary habits, and food frequency. The odds ratios were calculated by using unconditional logistic regression after adjusting for confounding variables. The mean age of the subjects was 50 yrs, and mean body mass index was significantly high in the patient group than in the control. The patient group had a significantly higher familial history of breast cancer and a significantly shorter breast-feeding period compared to the control group. It has been found no significant relationship between extrinsic hormone use such as oral contraceptives or estrogen replacement therapy and breast cancer risk. In regard of food habits, a high preference for the cooking method of steaming rather than frying, panbroiling or roasting was significantly associated with lower relative risk of breast cancer. The higher intake frequencies of fruits for all subjects, and seaweeds only for postmenopausal subjects were related with a significantly lower relative risk of breast cancer. The results of the study suggest that the possible risk factors for the breast cancer occurrence include high BMI, family history, less breast feeding experience, preference for the cooking method of frying, and less consumption of fruits and seaweeds. This study provides an useful data for nutrition education to prevent breast cancer for the residents in Daegu${\cdot}$Gyungbuk area.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Journal of Distribution Science
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• v.10 no.3
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• pp.43-50
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• 2012

This study sets out to examine how a brand image that matches the advertising model has a positive impact on brand attitude and price fairness perceptions. We reviewed the constructs on the basis of previous studies and each of the concepts has been redefined. One such concept, "image congruence," refers to the harmony, fitness, and matching quality of images. For example, how well celebrity advertising model is matches the brand image shows image congruence. Results are summarized as follows: First, the congruence of brand image and sports advertising model has no significant impact on brand attitude certainty and persistence. Second, the individual's brand attitude certainty and brand attitude persistence has a positive impact on the perceptions of price fairness. Third, the congruence of brand image and sports advertising model has a positive impact on the perceptions of price fairness. The first and the third results suggest that the positive impact on the price fairness perceptions is temporary but it has insignificant effects on the formation of brand attitude causing ongoing purchases. In other words, in order to influence consumers' long-term confidence on the brand, improving the quality of products or services has to precede promotional strategies such as advertising. When an advertising model is inappropriate for the brand image, consumers perceive product price changes as a negative issue in the short term. However, in the long term, attitude formation such as consumers' repurchase intentions and word of mouth will be not affected. The second result suggests that an already existing positive brand attitude can contribute more positively to change the perceptions of price fairness. In particular, attitude persistence has greater influence than attitude certainty on the price fairness. It suggests that persistence issues such as the trading period and the frequency of transactions must be managed and controlled because they are more important than the certainty issues such as strength of belief or trust. For example, when a commercial model for expensive sporting goods matches up with the brand image, consumer feels less pressure on the price changes. However, it does not determine the consumer's repeated purchases or sustainable transactions and it also has no absolute impact on the brand trust. In other words, consumer brand attitude should be recognized and approached as a routine strategy in view of the result that it is of great value as a causal variable in the process of consumer decision-making.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.151-156
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• 2002

Root zone cooling, such as soil or nutrient solution cooling, is less expensive than air cooling in the whole greenhouse and is effective in promoting root activity, improving water absorption rate, decreasing plant temperature, and reducing high temperature stress. The heat transfer of a soil cooling system in a plastic greenhouse was analyzed to estimate cooling loads. The thermal conductivity of soil, calculated by measured heat fluxes in the soil, showed the positive correlation with the soil water content. It ranged from 0.83 to 0.96 W.m$^{[-10]}$ .$^{\circ}C$$^{[-10]}$ at 19 to 36％ of soil water contents. As the indoor solar radiation increased, the temperature difference between soil surface and indoor air linearly increased. At 300 to 800 W.m$^{-2}$ of indoor solar radiations, the soil surface temperature rose from 3.5 to 7.$0^{\circ}C$ in bare ground and 1.0 to 2.5$^{\circ}C$ under the canopy. Cooling loads in the root zone soil were estimated with solar radiation, soil water content, and temperature difference between air and soil. At 300 to 600 W.m$^{-2}$ of indoor solar radiations and 20 to 40％ of soil water contents,46 to 59 W.m$^{-2}$ of soil cooling loads are required to maintain the temperature difference of 1$0^{\circ}C$ between indoor air and root zone soil.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.4
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• pp.105-116
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• 2021

Objectives Lumbar herniated intervertebral disc (L-HIVD) is common disease in which Western-Korean collaborative treatment is performed in Korea. This study aimed to analyze Western-Korean collaborative treatment utilization of Korean patients with L-HIVD using Health Insurance Review & Assessment Service's Patients Sample Data. Methods This study used the Health Insurance Review & Assessment Service-National Patient Sample (HIRA-NPS) in 2018. Claim data of L-HIVD patients were extracted. The claim data were rebuilt with the operational concept of 'episode of care' and divided into Korean medicine episode group (KM), Western medicine episode group (WM) and collaborative treatment episode group (CT). General characteristics, medical expenses and healthcare utilization were analyzed. In addition, the difference of average visit day and average medical expenses between non-collaborative group (KM plus WM) and CT were analyzed by the propensity score matching method. Results A Total of 64,333 patients and 365,745 claims were extracted. The number of episodes of WM, KM and CT was 69,383 (92.97%), 3,903 (5.23%), and 1,341 (1.80%) respectively. The frequency of collaborative treatment episode was higher in women and the age of 50s. The most frequently described treatment in CT was acupuncture therapy. As a result of the propensity score matching, the number of visit days and medical expenses in the collaborative treatment group was higher than in the non-collaborative group. Conclusions The analysis of healthcare utilization of Korean-Western collaborative treatment may be used as basic data for establishing medical policies and systematic collaborative treatment model in the future.