• Nutrition Research and Practice
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• v.5 no.4
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• pp.313-321
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• 2011

The Korea Food and Drug Administration (KFDA) revised the Health Functional Food Act in 2008 and extended the form of health functional foods to general food types. Therefore, this study was performed to investigate consumers' perceptions of the expanded form of health functional food and to predict consumption patterns. For this study, 1,006 male and female adults aged 19 years and older were selected nationwide by multi-stage stratified random sampling and were surveyed in 1:1 interviews. The questionnaire survey was conducted by Korea Gallup. The subjects consisted of 497 (49.4%) males and 509 (50.6%) females. About 57.9% of the subjects recognized the KFDA's permission procedures for health functional foods. Regarding the health functional foods that the subjects had consumed, red ginseng products were the highest (45.3%), followed by nutritional supplements (34.9%), ginseng products (27.9%), lactobacillus-containing products (21.0%), aloe products (20.3%), and Japanese apricot extract products (18.4%). Opinions on expanding the form of health functional foods to general food types scored 4.7 points on a 7-point scale, showing positive responses. In terms of the effects of medicine-type health functional foods versus generic health functional foods, the highest response was 'same effects if the same ingredients are contained' at a rate of 34.7%. For intake frequency by food type, the response of 'daily consistent intake' was 31.7% for capsules, tablets, and pills, and 21.7% for extracts. For general food types, 'daily consistent intake' was 44.5% for rice and 22.8% for beverages, which were higher rates than those for medicine types. From the above results, consumers had positive opinions of the expansion of health functional foods to generic forms but are not expected to maintain accurate intake frequencies or amounts. Thus, continuous promotion and education are needed for proper intake of generic health functional foods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2401-2409
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• 2013

Reliability analysis with response surface method (RSM) was peformed for a offshore wind turbine (OWT) monopile, which is one of mostly used foundations under 25m seawater depth in the world. The behaviors of a real OWT monopile installed into sandy soils subjected to offshore environmental loads such as wind and wave were analysed using reliability design program (HSRBD) developed in KIOST. Sensitivity analysis of design variables for a OWT monopile with 6m diameter showed that the larger in pile diameter the smaller in probability of failure ($P_f$) of a horizontal deflection and a rotational angle at a pile top, but at a greater than 7m of pile diameter, the reduction rate of $P_f$ was almost constant. It is a necessary that appropriate local design criteria should be designated as soon as possible because there were significant differences on horizontal deflections; $P_f$ was 60% at a minimum criteria 15mm deflection, however, 1.5% $P_f$ when 60mm deflection using 1% of pile diameter from local design criterion standard. Finally, friction angle of sand among many design variables was found most influential design factor in OWT monopile design, and a sensitivity analysis is found an important process to understand which design variables can mostly reduce $P_f$ with a optimum design for maintaining OWT stability.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.812-826
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• 2012

The selection rate of tree burials (TB) is still low in spite of increasing concerns about TB and government's efforts to increase TB participation. It is necessary to understand the factors affecting TB selection. This study investigated the relationship between major variables (attitude: ATT; subjective norm: SN; perceived behavioral control: PBC) of Ajzen's theory of planned behavior (TPB), additional variable (custom: CUST), and intention to select TB by using structural equation modelling (SEM). Samples were selected from Gwang-ju citizens using proportionate stratified sampling (PST) by region during September of 2011. Four hundred and twelve responses were used for data analysis. The model showed fair goodness of fit. All four variables (ATT, SN, PBC, CUST) influenced intention to select TB. The four variables explained 53.0% of intention to select TB. SN(${\beta}$=0.459) was the most predictive variable on the intention, followed by ATT(${\beta}$=0.247), PBC(${\beta}$=0.152), and CUST(${\beta}$=0.102) in decreasing order. The results were discussed and some suggestions to increase the intention of tree burial selection were made.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.113-118
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• 2016

In this paper, a read-in integrated circuit (RIIC) for IR scene projectors (IRSPs) adopting a sub-frame control technique is proposed, which minimizes the reduction of the apparent temperature of the IR images projected from IRSPs operating at a frame rate of 30 Hz. The proposed sub-frame control technique significantly reduces the amount of scene data loss on capacitors, which is caused by leakage currents flowing through MOSFET switches during holding periods, by dividing a unit frame into 8 sub-frames and refreshing the same scene data for each sub-frame. A current-drive RIIC was designed for the higher apparent temperature of IR radiated from the emitter, and it receives the scene data as a form of analog voltages from an external DAC. A prototype chip with a $64{\times}32$ RIIC array was fabricated using Magnachip/SKhynix $0.35{\mu}m$ 2-poly 4-metal CMOS process, and the measured maximum output data current is $230.3{\mu}A$. This amount of current ensures the projection of IR images whose maximum apparent temperature is $366.2^{\circ}C$ in the mid-wavelength IR (MWIR) when applied to a prototype emitter having a resistance of $15k{\Omega}$.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.39-46
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• 2016

This paper describes the third order feedforward delta-sigma modulator with inverter-based integrators and a 1.5bit comparator for the application of audio signal processing. The proposed 3rd-order delta-sigma modulator is multi-bit structure using 1.5 bit comparator instead of operational amplifier. This delta-sigma modulator has high SNR compared with single-bit 4th-order delta-sigma modulator in a low OSR. And it minimizes power consumes and simplified circuit structure using inverter-based integrator and using inverter-based integrator as analogue adder. The modulator was designed with 0.18um CMOS standard process and total chip area is $0.36mm^2$. The measured power cosumption is 28.8uW in a 0.8V analog supply and 66.6uW in a 1.8V digital supply. The measurement result shows that the peak SNDR of 80.7 dB, the ENOB of 13.1bit and the dynamic range of 86.1 dB with an input signal frequency of 2.5kHz, a sampling frequency of 2.56MHz and an oversampling rate of 64. The FOM (Walden) from the measurement result is 269 fJ/step, FOM (Schreier) was calculated as 169.3 dB.

• Journal of IKEEE
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• v.13 no.4
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• pp.96-102
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• 2009

We investigate the characteristics of RJ (random jitter) in an analog fiber-optic link employing a MZM (Mach-Zehnder modulator) and an EDFA (Erbium-doped fiber amplifier). RJ has been measured using two methods, one of which derived from the noise spectrum of a RF spectrum analyzer and the other from the histogram data of a sampling oscilloscope. If the optical power and/or the RF power input to the MZM increase, RJ decreases due to the output signal power increase. For the optical link without EDFA, the minimum RJ is about 1 ps at an RF power of 10 dBm and an optical power of 8 dBm measured using the noise spectrum method. For the optical link with an EDFA, RJ decreases toward a jitter floor as the EDFA gain increases. If the gain increases further, it has been observed that RJ increases from the minimum. If the EDFA gain is fixed, RJ is smaller for the case of larger optical input power. As the EDFA gain increases, RJ reduction rate becomes greater for the case of lower optical input power.

• Journal of Astronomy and Space Sciences
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• v.31 no.1
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• pp.73-81
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• 2014

A package of space science instruments, dubbed the Instruments for the Study of Space Storms (ISSS), is proposed for the Next Generation Small Satellite-1 (NEXTSat-1), which is scheduled for launch in May 2016. This paper describes the instrument designs and science missions of the ISSS. The ISSS configuration in NEXTSat-1 is as follows: the space radiation monitoring instruments consist of medium energy particle detector (MEPD) and high energy particle detector (HEPD); the space plasma instruments consist of a Langmuir probe (LP), a retarding potential analyzer (RPA), and an ion drift meter (IDM). The space radiation monitoring instruments (MEPD and HEPD) measure electrons and protons in parallel and perpendicular directions to the geomagnetic field in the sub-auroral region, and they have a minimum time resolution of 50 msec for locating the region of the particle interactions with whistler mode waves and electromagnetic ion cyclotron (EMIC) waves. The MEPD measures electrons and protons with energies of tens of keV to ~400 keV, and the HEPD measures electrons with energies of ~100 keV to > ~1 MeV and protons with energies of ~10 MeV. The space plasma instruments (LP, RPA, and IDM) observe irregularities in the low altitude ionosphere, and the results will be compared with the scintillations of the GPS signals. In particular, the LP is designed to have a sampling rate of 50 Hz in order to detect these small-scale irregularities.

• Journal of Sensor Science and Technology
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• v.14 no.1
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• pp.33-41
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• 2005

For more convenient electrode-electrolyte interface impedance analysis in biosensor, a stand-alone impedance measurement system is required. In our study, we developed a PC-based portable system to analyze impedance of the electrochemical cell using microprocessor. The devised system consists of signal generator, programmable amplifiers, A/D converter, low pass filter, potentiostat, I/V converter, microprocessor, and PC interface. As a microprocessor, PIC16F877 which has the processing speed of 5 MIPS was used. For data acquisition, the sampling rate at 40 k samples/sec, resolution of 12 bit is used. RS-232 with 115.2 kbps speed is used for the PC communication. The square wave was used as stimuli signal for impedance analysis and voltage-controlled current measurement method of three-electrode-method were adopted. Acquired voltage and current data are calculated to multifrequency impedance signal after Fourier transform. To evaluate the implemented system, we set up the dummy cell as equivalent circuit of which was composed of resistor, parallel circuit of capacitor and resistor connected in parallel and measured the impedance of the dummy cell; the result showed that there exist accuracy within 5 % errors and reproduction within 1 % errors compared to output of Hioki LCR tester and HP impedance analyzer as a standard product. These results imply that it is possible to analyze electrode-electrolyte interface impedance quantitatively in biosensor and to implement the more portable high speed impedance analysis system compared to existing systems.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.4 s.117
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• pp.96-104
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• 2006

Impervious pavement is primary contributor to the malfunctioning of the urban water circulation system. The aim of this research is to provide basic information and data for new pavement materials and paving technology which could enhance the urban water circulation system. For the study purposes, physical properties of soils sampled from 16 stations were analyzed. The sampling spots were paved with grass block porous pavement material. The findings from the analysis are as follows. The hardness of soils under the pavement was $17{\sim}22mm$ for thoroughfare and $6{\sim}32mm$ for parking areas. The bulk density was $1.42{\sim}1.81g/cm^{3}$ for thoroughfare and $1.38{\sim}1.75g/cm^{3}$ for parking area. The solid phase ration was $46.9{\sim}62.5m^{3}/m^{3}$ for thoroughfare and $45.6{\sim}61.3m^{3}/m^{3}$ for parking area. The porosity was $37.5{\sim}53.1m^{3}/m^{3}$ for thoroughfare and $38.7{\sim}54.4m^{3}/m^{3}$ for parking area. The saturated hydraulic conductivity was $8{\sim}164mm/hr$ for thoroughfare and $14{\sim}201mm/hr$ for parking area. The saturated hydraulic conductivity of the H sample area (the area was completed three months ago) and that of the other area were compared. There was up to 80% decreases of the saturated hydraulic conductivity within one year after the completion of pavement. After the first year, decrease in the saturated hydraulic conductivity was modest. Also there are changes in both surface and under soil physical properties of the grass block porous pavement depending on compaction. The extent of change depends on the degree of compaction. All these factors are combined to influence the permeability of the soil under the pavements. The results of this suggest that it is required to develop a new pavement technology which ensures both the durability and porosity of the pavement to improve the water circulation system by applying Ecological Area Rate.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.4-15
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• 2005

Methylmercury (MeHg) is an environmental pollutant with neurotoxic effects on the central nervous system. The major exposure route of MeHg to humans is via consumption of fish and shellfish which accumulate the chemical through the food web in an aquatic environment. Hair mercury level is an excellent marker for MeHg exposure. We have been conducting a survey on hair mercury contents among general populations from 14 districts to estimate the current Japanese MeHg exposure level. Total mercury levels of all hair samples collected (12923 in total) were analyzed by the oxygen combustion-gold amalgamation method using an atomic absorption mercury detector. Multiple regression analysis revealed that mercury levels were significantly correlated with several covariates, such as sex, age, the amount of daily intake of total fish/shellfish, a preference for certain fish such as tuna or bonito, and artificial waving. The geometric means for the population without artificial waving were 2.47 and 1.65 ${\mu}g/g$ for males (n = 5623) and females (n = 3470), respectively. Hair mercury levels varied with age, and the variations were more significant in males. Since the difference between sexes was not evident at younger ages, some hormonal control might also be involved in the mercury uptake by human hair. The average mercury levels in our hair samples varied among the sampling districts. Tuna is a major carnivorous fish with high mercury accumulations that is often consumed in Japan. The amount of fish consumption and the preference rate far tuna would appear to be responsible far the regional variation in hair mercury levels in Japan. Recently, a provisional tolerable weekly intake (PTWI) of MeHg was revised by 61st JECFA to 1.6 ${\mu}g/kg/week$, which was about half that of the Japanese standard, and corresponded to a hair level of 2.2 ppm. The distribution of hair mercury levels in Japanese populations in the present study indicated that 25% of the Japanese females of child-bearing age were estimated to be exposed to MeHg over the PTWI level. This would reflect the high Japanese consumption of marine products. However, not only mercury contamination, but also the nutritional benefit may have to be considered when discussing the risk involved in the current level of fish and shellfish consumption in Japan.