• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.12
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• pp.1327-1336
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• 2007

In this paper, we propose a reconfigurable antenna which operates as a disk-loaded dipole antenna and a folded dipole antenna alternatively using RF on/off switches. The antenna can change its effective length to achieve dual-band operation; operates as the folded dipole antenna for stepping up the radiation resistance in low frequency band of $20{\sim}300$ MHz, and as the disk-loaded dipole antenna for an omni-directional radiation pattern (horizontal plane) and a donut-shaped radiation pattern (vertical plane) in high frequency band of $300{\sim}1.3$ GHz. In the low band, the proposed antenna shows higher gain than a conventional dipole antenna with a reduced antenna size. In the high band, the antenna maintains a broad beamwidth of about $80^{\circ}$, thus the antenna can be applicable to antennas for direction finding applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1010-1014
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• 2007

This study was designed to determine the trans fatty acid (tF A) contents of 41 take-out food items in Daejeon and Chungcheong Province. Total fatty acid composition and tFA contents of samples were determined by gas chromatography (GC) after fat extraction (Folch method). Maximum fat content among the observed samples was obtained from theater popcorn (13.74${/cdot}$38.09%) while minimum content was observed from the glutinous rice doughnut. 31${/cdot}$5.44%). The contents of tFA (g/100 g food) in toasts, glutinous rice doughnut and ggwabaegi (twisted doughnut sold in streets) ranged from 0.02 to 0.56 g while those in fried sweet potatostick (from highway resting place), fried squid and theater popcorn ranged from 0.05 to 3.08 g/100 g. As a result, most samples showed the tFA content as less than 1 g (g/100 g food) except one sample from theater popcorn which contained 3.08 g (g/100 g food) as tFA content.

• Korean Journal of Optics and Photonics
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• v.31 no.2
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• pp.96-104
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• 2020

A catadioptric omnidirectional zoom optical system using a hybrid lens (COZOSH) that performs simultaneously two functions of a lens and a mirror was designed at the visible wavelength range for daytime unmanned surveillance, and its performance was analyzed. The hybrid lens has lots of advantages in terms of fabrication and assembly of a COZOSH, because of the obviation of a lens boring process and reduction of the number of optical components. Additionally, we designed the COZOSH to expand the compressed inner-image region of a donut image at low spatial frequencies. As a result, the optimized design performance of the optical system that satisfies all initial design specifications was obtained from calculation of the modulation transfer function, spot diagram, and tolerance analysis. We confirmed that the COZOSH is a passively athermalized optical system under conditions of temperature variation from -30℃ to 50℃, by using athermalization analysis during zooming.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.748-751
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• 2003

Acrylamide is considered as potential carcinogen and genotoxicant. Swedish National Food Administration reported that acrylamide was detected in heat treated starch rich food products. Acrylamide formation during food processing was confirmed by researchers of other countries including UK, Norway, Japan, Switzerland, and United States. It is noticed that the formation of acrylamide in potato products was greater than other food products. It may be due to high concentration of asparagine and glucose in potato products comparing to those of other food products. Interaction between asparagine and glucose during heat treatment resulted in acrylamide formation via Maillard reaction. Analytical method (LC-MS/MS) adopted by FDA was performed to monitor acrylamide concentrations in domestic food products. Acrylamide quantitation in several food categories, such as raw materials, boiled foods, fried foods, hardtacks, breads, breakfast cereals, potato chips, french fries, biscuits, and others, were carried out.

• Journal of Conservation Science
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• v.37 no.3
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• pp.232-244
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• 2021

This study examined the physical attributes and heat treatment characteristics of glass beads excavated from the Gimhae area, which is the location of Geumgwan Gaya. This enabled classification of surface characteristics of the beads based on the investigation of the color, size, and shape. The glass beads were classified into eight color systems, with purplish-blue beads as the representative color. Bead size was categorized into three types depending on the outer diameter and how it increased over time. Bead shapes were categorized as round, tubular, or doughnut-shaped based on the inner diameter and length, with round being the typical shape. According to the degree of heat treatment, there are three types of cross-section for glass beads that are manufactured by the drawing technique, most of which are the HT-III type. In addition, it is estimated that the heat treatment technology has more considerable effects than other methods. Through non-destructive analysis, the chemical composition was obtained and categorized as flux, stabilizer, and colorant. Analysis confirmed the presence of 63 and 9 pieces in the potash and soda glass groups, respectively. Overall findings from the study highlighted a correlation between the chemical composition and the external factors such as color, size, shape, and manufacturing technology of glass beads recovered from Geumgwan Gaya, revealing characteristics related to that time and region.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.217-230
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• 2023

Purpose: The purpose of this study was to assess the diet intake status and quality of adults from North Korea who had lived in Seoul and Gyeonggi-do, using the nutrition quotient (NQ) for Korean adults. Methods: A number of 166 adults aged from 20 to 64 years were enrolled as study subjects. A structured questionnaire was used to collect information on their demographic characteristics, food consumption frequency, eating behaviors, and NQ. The NQ score was then used to measure the overall diet quality. The NQ score was composed of four major age-based categories. 'Balance', 'Diversity', 'Moderation', and 'Dietary behavior' were utilized as scores for measurements within each of the four categories. The scores for all four categories were summed up, resulting in the total NQ score. Participants' age groups were stratified by 20's, 30's, 40', and over 50's. A χ² test and generalized linear regression (GLM) model were used to assess a significance for difference of subject distribution in categorical and continuous variables in the food consumption frequency, eating behaviors, and NQ scores. Results: Participants in younger age groups were more likely to report consumption of ramyeon, fast food, sweet and greasy baked products, processed beverage, delivery food, and night snacks than the older age groups. Most importantly, participants in 20's age group were less likely to report the total NQ and moderation score than the 50's age group. Conclusion: In this study, the 20's age group displayed a lower NQ characteristic for an unbalanced diet. Therefore, it is imperative for adults from North Korea to be given individualized diet instructions along with nutritional education programs.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.61-69
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• 2008

Purpose: Micro-pinhole SPECT system with conventional multiple-head gamma cameras has the advantage of high magnification factor for imaging of rodents. However, several geometric factors should be calibrated to obtain the SPECT image with good image quality. We developed a simplified geometric calibration method for rotating triple-head pinhole SPECT system and assessed the effects of the calibration using several phantom and rodent imaging studies. Materials and Methods: Trionix Triad XLT9 triple-head SPECT scanner with 1.0 mm pinhole apertures were used for the experiments. Approximately centered point source was scanned to track the angle-dependent positioning errors. The centroid of point source was determined by the center of mass calculation. Axially departed two point sources were scanned to calibrate radius of rotation from pinhole to center of rotation. To verify the improvements by the geometric calibration, we compared the spatial resolution of the reconstructed image of Tc-99m point source with and without the calibration. SPECT image of micro performance phantom with hot rod inserts was acquired and several animal imaging studies were performed. Results: Exact sphere shape of the point source was obtained by applying the calibration and axial resolution was improved. Lesion detectibility and image quality was also much improved by the calibration in the phantom and animal studies. Conclusion: Serious degradation of micro-pinhole SPECT images due to the geometric errors could be corrected using a simplified calibration method using only one or two point sources.

• Journal of Nutrition and Health
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• v.43 no.5
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• pp.524-532
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• 2010

The Na, component of salt, can increase the risk of high blood pressure and hypertension. Especially, children are exposed to an increased risk of high sodium intake, because they often consume Na-rich processed foods and commercially prepared foods in the street. However, the database for the sodium and chloride content for these children's favorite foods is insufficient. In this study, the Na and Cl contents in 89 children's favorite foods were analyzed by using Instrumental Neutron Activation Analysis (INAA) method. The analyzed food items were presented after being classified into 33 kinds of food groups. The Na contents in 100 g children's favorite foods ranged from 0.3 mg to 35.1mg in fruits, 28.9mg to 82.5mg in milks, 127.2 mg to 602.2 mg in breads, cakes, sandwiches, and rice cakes, 2.5 mg to 1169.9 mg in candies, cookies and ice creams, 226.9 mg to 693.7 mg in commercially prepared street foods, and 103.4 mg to 875.8 mg in fast foods of westernized restaurant. Among children's favorite food groups, 100 g fried chicken, hotdog, burgers, and donuts contained an average Na of 536 mg, 553 mg, 794 mg, and 562.2 mg, respectively, so they are classified as 'high Na foods'. In contrast, 100 g fruits and dairy products contained Na an average 4.9 mg and 43.4 mg, respectively, being classified as 'low Na foods'. One serving of ramen, mandu noodle, and burger pizza can supply over 667mg Na, which is one third of the KDRI targeted intake. Likewise, the Cl contents in children's favorite foods were diverse according to food groups. The Cl contents in the analyzed foods differed from the 1.5 times of Na content, which is assumed in general. This study showed that the Na and Cl contents in children's favorite foods are very diverse. Conclusively, a strategy to reduce Na contents in the fast foods such as noodles and westernized restaurant foods is necessary for children health.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.95-104
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• 1990

This survey was performed to investigate the actual holding conditions of the electric tools, gas tools and small cooking tools in the four Korean big cities; Seoul, Pusan, Kwangju and Taejon. The results were as follows; 1. Each family had more than 8 items on the average, of 24 kinds of electric tools under investigation. The holding ratio of refrigerators was the highest (99.6%), and that of dish washers was the lowest (3.4%). 2. The holding ratio of gas-ranges was the highest(92.2%) and that of gas-ovens was the lowest (2.2%) of 4 kinds of gas tools under investigation. 3. Each family had more than 45 items on the average, of 86 kinds of small cooking tools under investigation. The holdings ratios of openers and wicker baskets were very high (98.2% and 96.6%, respectively), and those of noodle tools and Shinsonros were very low (13.8% and 13.6%, respectively). 4. The holding ratios of various kinds of cooking tools had interrelations with the size of city, housewife's educational background, family income, house style, private residence, etc.

• Korean journal of food and cookery science
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• v.9 no.1
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• pp.7-13
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• 1993

This survey was performed to investigate the holding amount of the various kinds of cooking tools of the farm and fishing villages in Chungnam area. The results were as follows: 1. The holding ratio of refrigerators was the highest (97.9%), and that of toasters was the lowest (1.9%) among the electric tools. 2. The holding ratio of gas-ranges was the highest (95.7%) and that of gas oven-ranges was the lowest (1.2%) among 4 kinds of gas tools under investigation. 3. The holding amount of pans was the highest among the cooking tools and that of wicker baskets was very high among the small cooking tools. The holding ratios of egg-cutters and lemon-squeezers were very low (4.1% and 2.9%, respectively). 4. The holding ratios of various kinds of cooking tools were related to the housewife's educational background and family income.