• Title/Summary/Keyword: Half Life Time

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The Housewife's Current Use and Demand for Processed Rice Food Products (주부 소비자의 쌀 가공제품 이용실태 및 요구도 조사)

  • Kim, Soo-Min;Lee, Jin-Sil;Han, Jung-A;Kim, Young-Sik;Paik, Jin-Kyung;Hwang, Hye-Sun;Yi, Na-Young;Park, Dae-Seop;Hong, Wan-Soo
    • Korean journal of food and cookery science
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    • v.29 no.2
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    • pp.95-104
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    • 2013
  • This study was conducted to investigate the current use and the demand for processed rice food products by full-time and working housewives in a metropolitan area. Out of 330 questionnaires distributed, 300 were analyzed(90.9% response rate). It was revealed that more than half of the respondents(54.0%) had used processed rice food products, regardless of their occupation. Most respondents stated that they used rice food products because of the variety of the products, digestibility and the taste. The development necessity for processed rice food products was analyzed, showing that rice cake(3.86), rice sauce(3.64), and rice cookie(3.89) had the highest score in each category. The average demand for education and promotion of rice food products was 3.89; among 7 items, menu recipe using rice flour was highly demanded(4.18) by the respondents. Approximately 43.0% of the respondents agreed that the internet is the most effective method for learning about rice flour cooking, and the respondents who have used processed rice food products(59.5%) were more likely to attend education programs compared to housewives who have not used processed rice food products (44.5%)(p<.05). Full-time housewife(59.4%) had a greater tendency to participate in the education program than working woman(44.4%)(p<.001). The findings suggested that various processed rice flour products with convenience to use and prolonged shelf-life will be needed.

Synthesis and Characterization of Interfacial Properties of Sorbitan Laurate Surfactant (Sorbitan Laurate 계면활성제 합성 및 계면 특성에 관한 연구)

  • Lee, Seul;Kim, ByeongJo;Lee, JongGi;Lim, JongChoo
    • Applied Chemistry for Engineering
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    • v.22 no.1
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    • pp.37-44
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    • 2011
  • The critical micelle concentration (CMC) of sorbitan laurate SP 20 surfactant in this paper was near $7.216{\times}10^{-4}mol/L$ and the surface tension at CMC was about 26.0 mN/m, which showed higher CMC and lower surface tension than those of octylphenol ethoxylate octylphenol ethoxylate (OPE) 10 surfactant. Dynamic surface tension measurement using a maximum bubble pressure tensiometer showed that the adsorption rate at the interface between air and surfactant solution was found to be slower with SP 20 surfactant, presumably due to a low mobility of SP 20 surfactant monomer. The contact angle of SP 20 surfactant solution was observed to decrease with an increase in surfactant concentration and showed a larger value than that of OPE 10 surfactant solution. Half-life time for foams generated with 1 wt% surfactant solution was also larger with SP 20 surfactant, which indicated higher foam stability with SP 20 surfactant. Dynamic behavior study reveals that the solubilization of n-decane oil was much lower with SP 20, which is in good agreement with experimental results of foam stability, contact angle and CMC. Dynamic interfacial tension measurement by a spinning drop tensiometer shows that interfacial tensions at equilibrium condition in both systems were almost the same but the time required to reach equilibrium was longer with SP 20.

Alternative Immunossays

  • Barnard, G.J.R.;Kim, J.B.;Collins, W.P.
    • Korean Journal of Animal Reproduction
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    • v.9 no.2
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    • pp.133-139
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    • 1985
  • An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

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Citing Behavior of Korean Scientists on Foreign Journals in KSCD (KSCD를 활용한 국내 과학기술자의 해외 학술지 인용행태 연구)

  • Kim, Byung-Kyu;Kang, Mu-Yeong;Choi, Seon-Heui;Kim, Soon-Young;You, Beom-Jong;Shin, Jae-Do
    • Journal of the Korean Society for information Management
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    • v.28 no.2
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    • pp.117-133
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    • 2011
  • There have been little comprehensive research for studying impact of foreign journals on Korean scientists. The main reason for this is because there was no extensive citation index database of domestic journals for analysis. Korea Institute of Science and Technology Information (KISTI) built the Korea Science Citation Database (KSCD), and have provided Korea Science Citation Index (KSCI) and Korea Journal Citation Reports (KJCR) services. In this article, citing behavior of Korean scientists on foreign journals was examined by using KSCD that covers Korean core journals. This research covers (1) analysis of foreign document types cited, (2) analysis of citation counts of foreign journals by subject and the ratio of citing different disciplines, (3) analysis of language and country of foreign documents cited, (4) analysis of publishers of journals and whether or not journals are listed on global citation index services and (5) analysis for current situation of subscribing to foreign electronic journals in Korea. The results of this research would be useful for establishing strategies for licensing foreign electronic journals and for information services. From this research, immediacy citation rate (average 1.46%), peak-time (average 3.9 years) and half-life (average 8 years) of cited foreign journals were identified. It was also found that Korean scientistis tend to cite journals covered in SCI(E) or SCOPUS, and 90% of cited foreign journals have been licensed by institutions in Korea.

Residue of Pesticides Carbendazim and Chlorpyrifos in Different Parts of Red Pepper (고추의 부위별 카벤다짐과 클로르피리포스의 잔류 양상)

  • Park, Hae-In;Hwang, Jae-Moon;Kim, Byung-Soo;Lee, Mi-Gyeong;Chol, Young-Wook;Lee, Min-Ho;Jeong, Jeong-Eun;Kim, Jeong-Han
    • The Korean Journal of Pesticide Science
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    • v.15 no.3
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    • pp.246-253
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    • 2011
  • This experiment was carried out to examine the residual amount variation of carbendazim and chlorpyrifos in fruit parts of red pepper according to the open field and/or the rain shelter house. It was shown higher residual amounts of agrochemicals in the field than the house condition at two hours (0 day) after chemical application, but it was shown higher residual amounts in the house at 5 days and 10 days. Although the residual amount in the field was higher than in the house at the beginning, the chemicals fast degraded in field condition. Carbendazim and chlorpyrifos remained as time passed in order of receptacle, but the residual amounts of two chemicals in leaf at $5^{th}$ day. Carbendazim and chlorpyrifos were lessened until 10 days after chemical application, and reduction rate were 19.1% and 66.4% in flesh, 45.2% and 62.3% in receptacle, and 41.6% and 72.0% in the stalk, respectively. The reduction rate at 15 days showed 31.1%, 75.3% in flesh, 43.5%, 81.7% in receptacle, and 47.7%, 82.8% in stalk, respectively. Therefore the reduction rate of carbendazim showed receptacle > stalk > flesh, and that of chlorpyrifos showed stalk > receptacle > flesh in order. The calculated half-life of carbendazim showed 29.6 days in flesh, 13.6 days in receptacle, and 16.0 days in stalk, but that of chlorpyrifos showed 8.3 days in flesh, 8.3 days in receptacle, and 6.3 days in stalk. In conclusion, the half-life of carbendazim was longer than that of chlorpyrifos in even part, and especially was longest in flesh part of fruit.

Optimization of Interesterification Reaction for the Continuous Production of trans-Free Fat in a Packed Bed Enzyme Bioreactor with Immobilized Lipase (고정화 리파제를 이용한 충진형 효소생물반응기 내에서의 무-트랜스 유지 연속 생산을 위한 에스테르 교환 반응의 최적화)

  • Kim, Sang-Woo;Park, Kyung-Min;Ha, Jae-Uk;Lee, Jae-Hwan;Chang, Pahn-Shick
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.173-178
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    • 2009
  • Epidemiological studies showed that high trans-fat consumption is closely associated with getting the risks of cardiovascular disease. The objective of this study was to produce trans-free fat through lipase-catalyzed interesterification, as a substitute for the cream margarine commonly used in industry. Optimum conditions for interesterification in a packed bed enzyme bioreactor (PBEB) were determined using response surface methodology (RSM) based on central composite design. Three kinds of reaction variables were chosen, such as substrate flow rate (0.4-1.2 mL/min), reaction temperature (60-70$^{\circ}C$), and ratio of fully hydrogenated canola oil (FHCO, 35-45%) to evaluate their effects on the degree of interesterification. Optimum conditions from the standpoint of solid fat content (SFC) were found to be as follows: 0.4 mL/min flow rate, 64.7$^{\circ}C$ reaction temperate, and 42.8% (w/w) ratio of FHCO, respectively. The half-life of immobilized lipase in PBEB with two stages at 60$^{\circ}C$ ($1^{st}$ stage) and 55$^{\circ}C$ ($2^{nd}$ stage) was about more than 30 days as estimated by extrapolating the incubation time course of tristearoyl glycerol (TS) conversion, whereas the half-life of the enzyme in PBEB with single stage at 65$^{\circ}C$ was only about 15 days. Finally, the results from SFC analysis suggest that trans-free fat produced in this study seems to be a suitable substitute for the cream margarine commonly used in industry.

The Effect of PET Scan Time on the Off-Line PET Image Quality in Proton Therapy (양성자 치료에서 영상 획득 시간에 따른 Off Line PET의 효율성 검증)

  • Hong, Gun-Chul;Jang, Joon-Yung;Park, Se-Joon;Cha, Eun-Sun;Lee, Hyuk
    • The Korean Journal of Nuclear Medicine Technology
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    • v.21 no.2
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    • pp.74-79
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    • 2017
  • Purpose Proton therapy can deliver an optimal dose to tumor while reducing unnecessary dose to normal tissue as compared the conventional photon therapy. As proton beams are irradiated into tissue, various positron emitters are produced via nuclear fragmentation reactions. These positron emitters could be used for the dose verification by using PET. However, the short half-life of the radioisotopes makes it hard to obtain the enough amounts of events. The aim of this study is to investigate the effect of off-line PET imaging scan time on the PET image quality. Materials and Methods The various diameters of spheres (D=37, 28, 22 mm) filled with distilled water were inserted in a 2001 IEC body phantom. Then proton beams (100 MU) were irradiated into the center of the each sphere using the wobbling technique with the gantry angle of $0^{\circ}$. The modulation widths of the spread out bragg peak were 16.4, 14.7 and 9.3 cm for the spheres of 37, 28 and 22 mm in diameters respectively. After 5 min of the proton irradiation, the PET images of the IEC body phantom were obtained for 50 min. The PET images with different time courses (0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min) were obtained by dividing the frame with a duration of 10 min. In order to evaluate the off-line PET image quality with the different time courses, the contrast-to-noise ratio (CNR) of the PET image calculated for each sphere. Results The CNRs of the sphere (D=37 mm) were 0.43, 0.42, 0.40, 0.31 and 0.21 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNRs of the sphere (D=28 mm) were 0.36, 0.32, 0.27, 0.19 and 0.09 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNR of 37 mm sphere was decreased rapidly after 30 min of the proton irradiation. In case of the spheres of 28 mm and 22 mm, the CNR was decreased drastically after 20 min of the irradiation. Conclusion The off-line PET imaging time is an important factor for the monitoring of the proton therapy. In case of the lesion diameter of 22 mm, the off-line PET image should be obtained within 25 min after the proton irradiation. When it comes to small size of tumor, the long PET imaging time will be beneficial for the proton therapy treatment monitoring.

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Performance Characteristics of 3D GSO PET/CT Scanner (Philips GEMINI PET/DT) (3차원 GSO PET/CT 스캐너(Philips GEMINI PET/CT의 특성 평가)

  • Kim, Jin-Su;Lee, Jae-Sung;Lee, Byeong-Il;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.4
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    • pp.318-324
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    • 2004
  • Purpose: Philips GEMINI is a newly introduced whole-body GSO PET/CT scanner. In this study, performance of the scanner including spatial resolution, sensitivity, scatter fraction, noise equivalent count ratio (NECR) was measured utilizing NEMA NU2-2001 standard protocol and compared with performance of LSO, BGO crystal scanner. Methods: GEMINI is composed of the Philips ALLEGRO PET and MX8000 D multi-slice CT scanners. The PET scanner has 28 detector segments which have an array of 29 by 22 GSO crystals ($4{\times}6{\times}20$ mm), covering axial FOV of 18 cm. PET data to measure spatial resolution, sensitivity, scatter fraction, and NECR were acquired in 3D mode according to the NEMA NU2 protocols (coincidence window: 8 ns, energy window: $409[\sim}664$ keV). For the measurement of spatial resolution, images were reconstructed with FBP using ramp filter and an iterative reconstruction algorithm, 3D RAMLA. Data for sensitivity measurement were acquired using NEMA sensitivity phantom filled with F-18 solution and surrounded by $1{\sim}5$ aluminum sleeves after we confirmed that dead time loss did not exceed 1%. To measure NECR and scatter fraction, 1110 MBq of F-18 solution was injected into a NEMA scatter phantom with a length of 70 cm and dynamic scan with 20-min frame duration was acquired for 7 half-lives. Oblique sinograms were collapsed into transaxial slices using single slice rebinning method, and true to background (scatter+random) ratio for each slice and frame was estimated. Scatter fraction was determined by averaging the true to background ratio of last 3 frames in which the dead time loss was below 1%. Results: Transverse and axial resolutions at 1cm radius were (1) 5.3 and 6.5 mm (FBP), (2) 5.1 and 5.9 mm (3D RAMLA). Transverse radial, transverse tangential, and axial resolution at 10 cm were (1) 5.7, 5.7, and 7.0 mm (FBP), (2) 5.4, 5.4, and 6.4 mm (3D RAMLA). Attenuation free values of sensitivity were 3,620 counts/sec/MBq at the center of transaxial FOV and 4,324 counts/sec/MBq at 10 cm offset from the center. Scatter fraction was 40.6%, and peak true count rate and NECR were 88.9 kcps @ 12.9 kBq/mL and 34.3 kcps @ 8.84 kBq/mL. These characteristics are better than that of ECAT EXACT PET scanner with BGO crystal. Conclusion: The results of this field test demonstrate high resolution, sensitivity and count rate performance of the 3D PET/CT scanner with GSO crystal. The data provided here will be useful for the comparative study with other 3D PET/CT scanners using BGO or LSO crystals.

Cultivation of Oyster Mushroom[Pleurotus ostreatus (Jacq. ex Fr.) Kummer] at Medium with Ca(OH)2 Treatment (수산화칼슘[Ca(OH)2] 처리 배지를 이용한 느타리버섯의 재배)

  • Baek, Seung-Hwa;Lee, Yeong-Il;Yoo, Ki-Yong;Han, Seong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.27 no.4
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    • pp.303-313
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    • 2008
  • This research is aimed to investigate the cultivation method of oyster mushroom[Pleurotus ostreatus (Jacq. ex Fr.) Kummer] at the non-sterilized medium with $Ca(OH)_2$ treatment. Therefore, experiments were carried out to develop non-sterilization method of medium by addition of $Ca(OH)_2$ for omission of heat sterilization progress of medium. General components, minerals and amino acid in Jiri wild type No. 1 (Pleurotus ostreatus) and production cost were analyzed. For the purpose of omission of heat sterilization progress, treatment ratio of $Ca(OH)_2$ (purity 95%) was 5%(w/w) of dry medium. Initial pH of this medium was 11 and then the pH was changed by 9 after the uniform mixing of the medium for half an hour. The various germs occurred 50% and 100% at pH 8 and pH 7 of the non-sterilized medium, respectively. Production of oyster mushroom increased by $2,030\;ton\;ha^{-1}$ when the main raw material used corn pith instead of waste cotton. The time required of mycelium culture was 30 days when hypha was cultured at the non-sterilized medium, and pinhead occurred when 2 or 3 days was passed after the time required of mycelium culture. Occurrence of pinhead was most rapid at the condition of $22{\sim}26^{\circ}C$, 65% humidity and pH $6.5{\sim}7.0$ and required of $22{\sim}28$ days at $70{\sim}80\;mm$ thickness of non-sterilized medium. Ca content in 1st harvest oyster mushroom was higher than that in 2nd harvest one, and its difference was $30.3\;mg\;kg^{-1}$. Amino acid content by stipe thickness of oyster mushroom was ranged from 411.2 to $343.9\;mg\;kg^{-1}$ both in a pileus and a stipe of 1st harvest mushroom, and from 402.4 to $498.2\;mg\;kg^{-1}$ and from 442.6 to $470.4\;mg\;kg^{-1}$ in those of 2nd harvest one, respectively. The results of the present study suggest that the non-sterilization medium by addition of $Ca(OH)_2$ is usable with the cultivation of oyster mushroom.

A Study on the Well-being Related Awareness and Dietary Life Pattern in Urban Housewives (도시 주부들의 웰빙에 대한 인식과 식생활유형에 대한 연구)

  • Park, Young-Sim;Myung, Choon-Ok;Lee, Ki-Wan;Nam, Hae-Won
    • Journal of the Korean Society of Food Culture
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    • v.20 no.5
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    • pp.574-583
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    • 2005
  • To investigate the importance and practice of well-being related dietary life pattern such as purchasing food materials, food habits and eating out, a survey was conducted by questionnaire and 5-point Likert score in Seoul and Gyeonggi-Do, September, 2004 and April, 2005. The responses of 732 housewives who were over 40 years were analyzed by SPSS package program. The results were as follows. Most of them were 40-49 years(74.4%), graduated highschool (66.6%) and their family type was nuclear family type(81.4%). Almost half of them had full-time job (37.1%) and part time job (15.4%). The average importance score of 'food habits', 'purchasing food materials' and 'eating out' were $4.15{\pm}0.91,\;4.06{\pm}0.96\;and\;3.25{\pm}1.01$ respectively. But the average practice score of 'food habits' was greater($3.58{\pm}1.06$) than 'purchasing food materials ($3.19{\pm}1.19$)' and 'eating out($2.54{\pm}1.05$)'. Among 5 types of 'food habits', the type of 'cut down on eating fast food' had the greatest score of importances ($4.31{\pm}0.97$) but the difference between importance and practice was greatest(0.94). Also 'consume home-made food rather than processed or ready to food' showed great scores in importance ($4.28{\pm}0.87$) and practice($3.87{\pm}1.04$). 'Consume fruits and vegetables rather than meats' and 'avoid heavy use of oils' had the importance score of $4.04{\sim}4.19$. But the practice score of 'avoid heavy use of oils' was the lowest($3.39{\pm}0.97$). Among four types of purchasing of food materials, 'purchase domestic agricultural food' was greatest($4.37{\pm}0.78$) and 'don't purchase genetically modified food' 'purchase organic food' and 'purchase whole grain products' were also great ($3.92{\sim}3.99$). But the practice score of 'purchase organic/low chemical foods($2.77{\pm}0.98$)' and 'don't purchase genetically modified food($2.99{\pm}1.41$)' were lowest. 'Go to well being restaurant' in three types of 'eating out' showed greatest in importance($3.35{\pm}0.96$) but the practice score($2.47{\pm}0.10$) was lower than the importance score. Also 'choose menu with comparing calories' had the lower score in practice($2.45{\pm}1.06$) rather than importance score($3.22{\pm}1.03$). In regarding to 'food habits', the importance score were significantly affected by type of food expense (p<0.05) and health status (p<0.05). The importance score of 'purchase food materials' were significantly affected by the type of food expense (p<0.001), type of residence(p<0.05), and self assessment of weight(p<0.05). Monthly income, especially more 400 million won, was the commonly significant effector in practice score of 'purchase food materials' and 'eating out'.