• Journal of Community Nutrition
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• v.5 no.1
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• pp.37-43
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• 2003

Iron deficiency and anemia are severe nutrition problems in most of Korea. Iron intake, especially iron with better bioavailability is insufficient over a total age group. Recent changes in diet and life style of Koreans have been repeatedly suggested problems caused by excess nutrient intake rather than under intake. Despite the changes in diet patterns, iron deficient anemia is still prevalent in many parts of Korea. Eight hundred and fifty subjects (323 male and 527 female subjects) in Asan were recruited from farming, factory and urban area. Each subject was interviewed to assess nutrients intakes according to a 24hr-recall method. Twelve hour fasting blood samples were collected to vacutainer with EDTA for hemoglobin (Hb) and separate the tubes for serum iron (SI) and total iron binding capacity (TIBC). The mean serum iron value of female subjects in the factory area was significantly higher (p < 0.05) than that of the female subjects in the urban area although subjects in urban area showed significantly higher the dietary iron intake for both the men and woman (p < 0.05). Dietary iron intake for the younger women was lowest in the farming area and those in the urban area showed the highest dietary iron intake (p < 0.05). When the dietary iron intake was compared by different the age groups, dietary iron intake of the older women from animal sources was less than that of younger women in the urban area (p < 0.05). Dietary iron intake of Asan residents was not sufficient regardless of age, sex and regions and intake of heme iron was especially lower than nonheme iron. (J Community Nutrition 5(1) : 37∼43, 2003)

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.45-50
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• 2004

The field utilization factor (equation omitted) (the mean electric field / the maximum electric field) of standard sphere gaps was calculated by the charge simulation method, taking into account the ground plane and shanks. n changes mainly with g/r and slightly with 1$_1$, 1$_2$ and 1, where D=2r is the sphere diameter, g is the gap length, 1$_1$ and 1$_2$, respectively, are the lengths of the upper and lower shank, and t is the shank diameter. Generally, (equation omitted) increases as 1$_1$,1$_2$ and t each becomes larger. IEC standard 60052(2002) limits t$\leq$0.2D 1$_1$$\geq$1D and prescribes A=1$_2$＋D＋g where A is the height of the spark point on the upper sphere. Therefore, (equation omitted) is the largest when A=9D and the smallest when A=3D. The simple equation of a straight line, (equation omitted)=1- (g/3r), can generally be used as a representative value of (equation omitted) for a wide variety of sphere diameters that are permitted by the IEC standard. The maximum electric field E$_{m}$ at sparkover of standard air gaps has also been calculated by the relation E$_{m}$=V/(equation omitted)g). E$_{m}$ describes a U-curve for g/r, up to the sphere diameter of 1 m. Moreover, for 1.5-m and 2-m diameters and especially .for negative polarity, sparkover voltages have been calculated by integration of the ionization index.index.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11B
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• pp.997-1004
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• 2006

There is a growing demand to access the broadband internet while on the very fast move. In order to meet these users needs, much research has been made for providing the broadband internet and HDTV services via satellite broadband internet systems even at top train speeds above 200km/h. In this paper, economic analyses on the satellite broadband internet services for KTX are to be reviewed. Broadband internet to trains in Europe are investigated, and Boeing cases for planes are also examined. In the first step, system configuration which is composed of a hub, terminals, satellite, and gap fillers for the tunnel areas has been proposed. A terminal includes a ultra-fast high gain antenna installed on the roof of the train, and APs inside the coaches. Secondly, cost estimation on the capital expenditures as well as operating expenditures has been performed in the proposed configuration. From the european and Boeing cases, demand and tariff are postulated, consequently, service revenues are derived on the scenario basis. Thirdly, estimated costs and derived revenues make up net present value and internal rate of return in each scenario. Finally, conclusions and contribution of this study are presented.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.454-460
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• 2012

The purpose of the present work is to investigate the removal characteristics of positively charged filters for capturing negatively charged particles such as bacteria and virus in water. In order to reduce the pressure drop and increase the filtration efficiency, the filter media, modified by charge modifier having positive functional groups, is developed and evaluated. Improved liquid filters have been developed with the modified surface charge to capture and adsorb particles by electrokinetic interaction between the filter surface and particles contained in an aqueous liquid. The positively charged filter media is composed of glass fiber, cellulose and poly-ethylenimine resin for positively charging with the variation of volume ratio. The zeta potential value of the positively charged filter is +37.92 mV at the glass fiber and cellulose content ratio of 50 : 50 with resin content of 100%, while that of the PSL test particle is -23.5 mV at pH 7. The removal efficiency of the electro-positively charged filter is 98% for PSL particles of 0.11 ${\mu}m$, while that of the negatively charged filter is 7%. The positively charged filter media showed the potential to be an effective method for removing fine particles from the contaminated water for liquid filtration.

• Restorative Dentistry and Endodontics
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• v.37 no.3
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• pp.136-141
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• 2012

Objectives: The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. Materials and Methods: Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. Results: The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. Conclusions: These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.874-882
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• 2003

The condition assessment of engineering systems has increased in importance because the manpower needed to operate and supervise various plants has been reduced. Especially, induction motors are at the core of most engineering processes, and there is an indispensable need to monitor their health and performance. So detection and diagnosis of motor faults is a base to improve efficiency of the industrial plant. In this paper, a model-based fault detection system is developed for induction motors, using steady state vibration signals. Early various fault detection systems using vibration signals are a trivial method and those methods are prone to have missed fault or false alarms. The suggested motor fault detection system was developed using a model-based reference value. The stationary signal had been extracted from the non-stationary signal using a data segmentation method. The signal processing method applied in this research is FFT. A reference model with spectra signal is developed and then the residuals of the vibration signal are generated. The ratio of RMS values of vibration residuals is proposed as a fault indicator for detecting faults. The developed fault detection system is tested on 800 hp motor and it is shown to be effective for detecting faults in the air-gap eccentricities and broken rotor bars. The suggested system is shown to be effective for reducing missed faults and false alarms. Moreover, the suggested system has advantages in the automation of fault detection algorithms in a random signal system, and the reference model is not complicated.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1485-1490
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• 2014

We have designed and developed a new ladder type tetrafused ${\pi}$-conjugated building block such as dihydroindolo[3,2-b]indole (DINI) and investigated its role as an electron rich unit. The photovoltaic properties of a new semiconducting ${\pi}$-conjugated polymer, poly[[5,10-bisoctyl-5,10-dihydroindolo[3,2-b]indole-[5,6- bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole]], represented by PDINI-OBTC8 are described. The new polymer PDINI-OBTC8 was synthesized in donor-acceptor (D-A) fashion, where fused ${\pi}$-conjugated tetracyclic DINI, and 5,6-bis(octyloxy)-4,7-di(thiophen-2-yl) benzo[c][1,2,5]thiadiazole (OBTC8) were employed as electron rich (donor) and electron deficient (acceptor) moieties, respectively. The conventional bulk heterojunction (BHJ) device structure ITO/PEDOT:PSS/PDINI-OBTC8:PCB71M/LiF/Al was utilized to fabricate polymer solar cells (PSCs), which comprises the blend of PDINI-OBTC8 and [6,6]-phenyl-$C_{71}$-butyric acid methyl ester ($PC_{71}BM$) in BHJ network. A BHJ PSC that contain PDINI-OBTC8 delivered power conversion efficiency (PCE) value of 1.68% with 1 vol% of 1,8-diidooctane (DIO) under the illumination of A.M 1.5G 100 $mW/cm^2$.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.325-330
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• 2011

In order to revive the ecological function of degraded rivers, a total restoration plan for riverbeds and riparians needs to be developed. Previous evaluations for rivers were mainly focused on the river's physical structures. Therefore, this research has developed indicators to evaluate a riparian restoration considering biodiversity. Through literature and previous cases review, 4 fields and 13 indicators are selected for the evaluation. Four fields are biodiversity, habitat diversity, connectivity and habitat functionality. In the biodiversity field, 4 indicators of the exuberant extent of herbaceous vegetation and their diversity, the exuberant extent of shrub and woody plants and their diversity, the number of plant communities and naturalized plants are included. Habitat diversity are comprised of 4 indicators of the longitudinal continuity of vegetation, the mixture of plant communities, the extent of plant type color fruit abundance and the distribution of vegetation. Connectivity includes 3 indicators of target distribution, the shore slope of low water channels and the extent of artificial embankment materials. Habitat functionality has 2 indicators of the status of food supply plants and the habitat functionality. The value weighting for the fields and indicators has been calculated based on the AHP(Analytic Hierarchy Process) method. 50 experts were surveyed with quantifiable questionnaire, among them 43 experts have more than 10 yesrs experiences in the nature restoration field. The selected and weighted indicators have been tested to the 12 sections in Gap stream located in Daejeon. In conclusion, the indicators are feasible and the selected indicators could be used to establish the direction and objectives of riparian restoration.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.6
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• pp.1-15
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• 1974

In this paper, the SH mode of elastic surface waves which are used for delay lines of elastic surface wave is the cretically analysed. It is shown that the SH mode has very large electromechanical coupling factor and propagates on the surface with very small decaying coefficient into the medium. In the case of P2T-4, the depth cf piezoelectric medium that contains 80% of energy is 190 wavelengths. An elastic surface wave delay line is discussed from the view point of 2-port network. Center frequency is shifted by the ratio of transducer electrode width to gap between transducer ellcerodes when electromechanical coupling factor is large. Tempera _ore coefficients for bulk waves of LiNbO3 and LiTaO3 are also calculated and the minimum temperature coefficient value of delay time is 5.4X 10-6/$^{\circ}C$ ia the case of transverse wave propagating along Z axis on LiTaO3. Experimental data are in good agreement with theoretical values of the temperature coefficients of delay time for elastic surface waves propagating along X axis of 130$^{\circ}$ and 64$^{\circ}$ rotated Y cut planes of the LiNbO3.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.211-215
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• 2015

In this paper, we propose a internal antenna for wirless HDMI dongle device using the folded monopole structure. The proposed antenna is for 2.4GHz and 5.8GHz. The antenna optimized for parameters length, gap, width, and radius of semicircular of monopole antenna using the 'F' structure. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. We used an FR4 dielectric substrate with a dielectric constant of 4.4. The HDMI dongle size of the proposed antenna is $45{\times}20{\times}1mm$, and the size of the antenna area is $5{\times}20mm$. There is a value of return loss less then -10dB in 2.4GHz and 5.8GHz, band and the maximum antenna gain is -4.13dBi. The result proved the possibility of the practical using 'F' structure that came frin comparing and analyzing the measured and simulated data of the antenna.