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유청단백질로 만들어진 식품포장재에 관한 연구

  • Kim, Seong-Ju
    • 한국유가공학회:학술대회논문집
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    • 2002.04a
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    • pp.59-60
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    • 2002
  • Edible films such as wax coatings, sugar and chocolate covers, and sausage casings, have been used in food applications for years$^{(1)}$ However, interest in edible films and biodegradable polymers has been renewed due to concerns about the environment, a need to reduce the quantity of disposable packaging, and demand by the consumer for higher quality food products. Edible films can function as secondary packaging materials to enhance food quality and reduce the amount of traditional packaging needed. For example, edible films can serve to enhance food quality by acting as moisture and gas barriers, thus, providing protection to a food product after the primary packaging is opened. Edible films are not meant to replace synthetic packaging materials; instead, they provide the potential as food packagings where traditional synthetic or biodegradable plastics cannot function. For instance, edible films can be used as convenient soluble pouches containing single-servings for products such as instant noodles and soup/seasoning combination. In the food industry, they can be used as ingredient delivery systems for delivering pre-measured ingredients during processing. Edible films also can provide the food processors with a variety of new opportunities for product development and processing. Depends on materials of edible films, they also can be sources of nutritional supplements. Especially, whey proteins have excellent amino acid balance while some edible films resources lack adequate amount of certain amino acids, for example, soy protein is low in methionine and wheat flour is low in lysine$^{(2)}$. Whey proteins have a surplus of the essential amino acid lysine, threonine, methionine and isoleucine. Thus, the idea of using whey protein-based films to individually pack cereal products, which often deficient in these amino acids, become very attractive$^{(3)}$. Whey is a by-product of cheese manufacturing and much of annual production is not utilized$^{(4)}$. Development of edible films from whey protein is one of the ways to recover whey from dairy industry waste. Whey proteins as raw materials of film production can be obtained at inexpensive cost. I hypothesize that it is possible to make whey protein-based edible films with improved moisture barrier properties without significantly altering other properties by producing whey protein/lipid emulsion films and these films will be suitable far food applications. The fellowing are the specific otjectives of this research: 1. Develop whey protein/lipid emulsion edible films and determine their microstructures, barrier (moisture and oxygen) and mechanical (tensile strength and elongation) properties. 2. Study the nature of interactions involved in the formation and stability of the films. 3. Investigate thermal properties, heat sealability, and sealing properties of the films. 4. Demonstrate suitability of their application in foods as packaging materials. Methodologies were developed to produce edible films from whey protein isolate (WPI) and concentrate (WPC), and film-forming procedure was optimized. Lipids, butter fat (BF) and candelilla wax (CW), were added into film-forming solutions to produce whey protein/lipid emulsion edible films. Significant reduction in water vapor and oxygen permeabilities of the films could be achieved upon addition of BF and CW. Mechanical properties were also influenced by the lipid type. Microstructures of the films accounted for the differences in their barrier and mechanical properties. Studies with bond-dissociating agents indicated that disulfide and hydrogen bonds, cooperatively, were the primary forces involved in the formation and stability of whey protein/lipid emulsion films. Contribution of hydrophobic interactions was secondary. Thermal properties of the films were studied using differential scanning calorimetry, and the results were used to optimize heat-sealing conditions for the films. Electron spectroscopy for chemical analysis (ESCA) was used to study the nature of the interfacial interaction of sealed films. All films were heat sealable and showed good seal strengths while the plasticizer type influenced optimum heat-sealing temperatures of the films, 130$^{\circ}$C for sorbitol-plasticized WPI films and 110$^{\circ}$C for glycerol-plasticized WPI films. ESCA spectra showed that the main interactions responsible for the heat-sealed joint of whey protein-based edible films were hydrogen bonds and covalent bonds involving C-0-H and N-C components. Finally, solubility in water, moisture contents, moisture sorption isotherms and sensory attributes (using a trained sensory panel) of the films were determined. Solubility was influenced primarily by the plasticizer in the films, and the higher the plasticizer content, the greater was the solubility of the films in water. Moisture contents of the films showed a strong relationship with moisture sorption isotherm properties of the films. Lower moisture content of the films resulted in lower equilibrium moisture contents at all aw levels. Sensory evaluation of the films revealed that no distinctive odor existed in WPI films. All films tested showed slight sweetness and adhesiveness. Films with lipids were scored as being opaque while films without lipids were scored to be clear. Whey protein/lipid emulsion edible films may be suitable for packaging of powder mix and should be suitable for packaging of non-hygroscopic foods$^{(5,6,7,8,)}$.

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Attitudes to Safety of Genetically Modified Foods in Korea -Focus on Consumers- (유전자재조합 식품의 안전성에 대한 기본인식 조사 -일반 소비자를 중심으로 _)

  • 김영찬;박경진;김성조;강은영;김동연
    • Journal of Food Hygiene and Safety
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    • v.16 no.1
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    • pp.66-75
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    • 2001
  • A survey was conducted to investigate consumers'attitudes toward the foods developed by gene recombination techniques from December, 1999 to April, 2000. The questionnaires were mailed to 1,500 people, and the 1,101 people responded. The consumers were asked about knowledge, acceptance, intention of purchasing, and labeling information. Although the portion of the consumers (88.8%) knowing the genetically modified floods (GMF) was lower than that of the flood expert group (98.7%), many consumers had some knowledge on the GMF, which may be influenced by news released from mass media. Seventy-nine percent of the consumers responded that gene recombination technology is necessary in food production, which is similar to the findings on the survey of the expert group. The portion of the consumers responding that these foods are potentially hazard was 88.1%, which is a little higher than the data (80.9%) from the expert group. The consumers having greater knowledge less worried about a potential hazard of the gene recombinant foods (p<0.01). Although 62.9% of the consumers responded to be willing to purchase those foods, only 16.2% of them responded to purchase the foods with no conditions, which is lower to that from the expert group (23.5%). There was no statistically significant relationship between the knowledge and the intention of purchasing. The ninety point three percent of the consumers wanted the information on gene recombination to be labeled on the foods. The data from this survey suggest that knowledge of the consumers on the GMF are not accurate, so proper strategy for consumer education may need to be developed. In addition, it is necessary to improve safety assessment system and analytical techniques for genetically modified foods (GMF) and to build pre- and post-market surveillance system fur efficient implementation of the GMF labeling.

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A Study on Avant-Garde Fine Art during the period of Japanese Colonial Rule of Korea, centering on 'Munjang' (a literary magazine) (일제강점기 '전위미술론'의 전통관 연구 - '문장(文章)' 그룹을 중심으로)

  • Park, Ca-Rey
    • The Journal of Art Theory & Practice
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    • no.4
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    • pp.57-76
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    • 2006
  • From the late 1920s to the 1930s, Korea's fine art community focused on traditional viewpoints as their main topic. The traditional viewpoints were discussed mainly by Korean students studying in Japan, especially oil painters. Such discussions on tradition can be divided into two separate halves, namely the pre- and post-Sino-Japanese War (1937) periods. Before the war, the modernists among Korea's fine art community tried to gain a fuller understanding of contemporary Western modern art, namely, expressionism, futurism, surrealism, and so forth, on the basis of Orientalism, and borrow from these schools' in order to create their own works. Furthermore, proponents of Joseon's avant-garde fine arts and artists of the pro-fine art school triggered debate on the traditional viewpoints. After the Sino-Japanese War, these artists continued to embrace Western modern art on the basis of Orientalism. However, since Western modern fine art was regressing into Oriental fine art during this period, Korean artists did not need to research Western modern fine art, but sought to study Joseon's classics and create Joseon's own avant- garde fine art in a movement led by the Munjang group. This research reviews the traditional view espoused by the Munjang group, which represented the avant-garde fine art movement of the post-war period. Advocating Joseon's own current of avant-garde fine art through the Munjang literary magazine, Gil Jin - seop, Kim Yong-jun and others accepted the Japanese fine art community's methodology for the restoration of classicism, but refused Orientalism as an ideology, and attempted to renew their perception of Joseon tradition. The advocation of the restoration of classicism by Gil Jin-seop and Kim Yong-jun appears to be similar to that of the Yasuda Yojuro-style restoration of classicism. However, Gil Jin-seop and Kim Yong-jun did not seek their sources of classicism from the Three-Kingdoms and Unified Silla periods, which Japan had promoted as a symbol of unity among the Joseon people; instead they sought classicism from the Joseon fine art which the Japanese had criticized as a hotbed of decadence. It was the Joseon period that the Munjang group chose as classicism when Japan was upholding Fascism as a contemporary extremism, and when Hangeul (Korean writing system) was banned from schools. The group highly evaluated literature written in the style of women, especially women's writings on the royal court, as represented by Hanjungnok (A Story of Sorrowful Days). In the area of fine art, the group renewed the evaluation of not only literary paintings, but also of the authentic landscape paintings refused by, and the values of the Chusa school criticized as decadent by, the colonial bureaucratic artists, there by making great progress in promoting the traditional viewpoint. Kim Yong-jun embraced a painting philosophy based on the painting techniques of Sasaeng (sketching), because he paid keen attention to the tradition of literary paintings, authentic landscape paintings and genre paintings. The literary painting theory of the 20th century, which was highly developed, could naturally shed both the colonial historical viewpoint which regarded Joseon fine art as heteronomical, and the traditional viewpoint which regarded Joseon fine art as decadent. As such, the Munjang group was able to embrace the Joseon period as the source of classicism amid the prevalent colonial historical viewpoint, presumably as it had accumulated first-hand experience in appreciating curios of paintings and calligraphic works, instead of taking a logical approach. Kim Yong-jun, in his fine art theory, defined artistic forms as the expression of mind, and noted that such an artistic mind could be attained by the appreciation of nature and life. This is because, for the Munjang group, the experience of appreciating nature and life begins with the appreciation of curios of paintings and calligraphic works. Furthermore, for the members of the Munjang group, who were purists who valued artistic style, the concept of individuality presumably was an engine that protected them from falling into the then totalitarian world view represented by the Nishita philosophy. Such a 20th century literary painting theory espoused by the Munjang group concurred with the contemporary traditional viewpoint spearheaded by Oh Se-chang in the 1910s. This theory had a great influence on South and North Korea's fine art theories and circles through the Fine Art College of Seoul National University and Pyongyang Fine Art School in the wake of Korea's liberation. In this sense, the significance of the theory should be re-evaluated.

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Binocular Vision Corrective Spectacle Lenses Reduce Visual Fatigue in 3-D Television Viewing (양안시 교정안경의 3차원 텔레비전 시청 중 발생한 안정피로 감소)

  • Yoon, Jeong Ho;Kim, Jae-Do
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.363-369
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    • 2014
  • Purpose: Three-dimensional (3D) displays are very useful in many fields, but induce physical discomforts in some people. This study is to assess symptom type and severity of asthenopia with their habitual distance corrective spectacle (HDCS) and their binocular vision corrective spectacle lenses (BVCSL) in people who feel physical discomforts. Methods: 35 adult subjects (ages $32.2{\pm}4.4$ yrs) were pre-screened out of 98 individuals to have the highest symptom/asthenopia scores following 65 minutes of 3D television viewing with HDCS. These 35 individuals were then retested symptom/asthenopia scores during they watched 3D television for 65 minutes at a distance of 2.7 m with wearing BVCSL of horizontal, vertical or base down yoked prisms. A 4-point symptom-rating scale questionnaire (0=no symptom and 3=severe) was used to assess 11 symptoms (e.g., blur, diplopia, etc.) related to visual fatigue/visual discomfort. Distance and near lateral phoria were measured using Howell phoria card and vertical phoria were measured using Maddox rod. Symptoms induced by watching 3D TV were compared between wearing HDCS and BVCSL. Results: Asthenopia in watching 3D TV with wearing BVCS was significantly lower than wearing HDCS at 5, 25, 45, and 65 minutes (all p < 0.001, paired t-tests). In only refractive error power correction power group, all asthenopia was not significantly different between HDCS and BVCSL (all $p{\geq}0.05$, paired t-tests). In prism correction groups for binocular imbalance, symptoms of asthenopia, however, was significantly lower for when wearing BVCSL than when wearing HDCS (all p < 0.05). Conclusions: Correction of phoria/vergence-based binocular vision imbalance can reduce asthenopia during 3D television viewing. An individual with binocular vision imbalance need corrected/compensated glasses with appropriate prisms prior to prolonged viewing of 3D television displays to reduce asthenopia/visual fatigue.

A Study of material analysis and its experimentation of metamorphosis and its utilities in Copper Alloy plates for contemporary metal craft (현대금속공예용 동합금판의 재료분석과 형질변환 실험 및 응용에 관한 연구)

  • Lim, Ock-Soo
    • Archives of design research
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    • v.17 no.4
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    • pp.241-250
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    • 2004
  • In this research, the copper alloy plates C2200, C5210, C7701, C8113 were selected to make datum and to identify further usage of metal craft experimentation. For its experimentation, the general welding and TIG welding methods were researched; for 2nd experimentation, the Reticulation and Electroforming skill's differences in color and temperature were researched. With these methods 3 different kinds of works are introduced for sample studies. For this research, Dr. Lee, Dong-Woo who works in Poongsan Metal Co, supported 4 kinds of copper alloy metals. Which are Commercial bronze (Cu-Zn), Deoxidiged Copper(Cu-Sn-P), Nickel Silver (Cu-Ni-Zn), and White Bronze (Cu-Ni); they were applied partly and wholly by the method of Laminatin, Reticulation, Fusing, and Electroforming skills. In case of C2200, the brass, the A. C. TIG welding method is better under 2mm slight plate; the D.C. TIG welding is better upper 2mm plate; and 250~300$^{\circ}C$ is recommended for remain heat treatment. In case of C5210, not having Hydrogen in high temperature return period, doesn't need Oxygen in high temperature and hardening in comparative high temperature neither, it is good for welding. It contains Sn 2-9% ad P 0.03-0.4% generally; and in accordance with the growth rate of Sn contain amount, the harden temperature boundary become broad. In case of cold moment after welding, they are recommended that higher speed TIG welding, smaller melting site and less than 200$^{\circ}C$ for pre-heating temperature. In case of C7701, the 10-20% Ni, 15-30% Zn are widely used.. If it is upper 30% Zn, it become (${\alpha}+{\beta}$) system and adhesive power rate become lower, and the productivity become lower in low temperature but the productivity become higher in high temperature. Nickel Silver's resistance of electricity is well; and the heatproof and incorrodibility is good, too. Lastly, in case of C8113, good at persistence in salty and grind; high in strength of high temperature. In case of white brass, contain 10-30% Nickel and hardened in high temperature and become single phrase. For these reason, the crystallization particles easily become large, if the resistance become higher small amount of Pb, P, S separation rate become higher.

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Exploratory Study on the Effect of the Entrepreneurial Infrastructure Institution on the Regional Employment: Focusing on the Partner Square of N Company (창업 인프라 기관의 지역 고용효과에 관한 탐색적 연구: N사 파트너스퀘어를 중심으로)

  • Kim, Jong Sung;Shim, Jae Hun;Kim, Do Hyeon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.3
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    • pp.223-231
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    • 2020
  • Governments and private companies have established various local entrepreneurial infrastructure institutions in most regions in order to reduce youth unemployment, and boost youth entrepreneurship and regional employment. However, previous studies has been limited to explore the impact of the entrepreneurial infrastructure institutions on the willingness of start-up entrepreneurs. Thus, the main purpose of this study is to fill in the gaps of the research, identify the effect of the entrepreneurial infrastructure institutions on regional employment focusing on the Partner Squares which are entrepreneurial infrastructure institutions in several regions and established by N company, and set a foundation for further research regarding the effectiveness of the entrepreneurial infrastructure institutions. In order to verify the effectiveness of the Partner Squares on the local employment, we use the raw data of the Economically Active Population Survey (Statistics Korea) and analyze the effectiveness by using the Difference-in-Differences model. The main findings are as follows. While the Partner Square Seoul has not statistically influenced on the employment of local youth workers, the Partner Square Busan has increased about 3% of the average number of employees (575 thousand) from May 2017 to July 2019, increasing the number of local youth workers by 17,000. Also, after the establishment of the Partner Square Gwangju, the institution has increased 4,500 local employees, which is about 1.7% of the average number of employees (267,000) from September 2018 to July 2019. This implies that the Partner Squares provide a variety of effective start-up education programs and networks for pre-starters and founders in the region, thereby helping them to grow and boosting the local employment. An important implication is that by using government statistical data, we find roles of entrepreneurial infrastructure institutions to revitalize local economy and employment. In future studies, studies need to be conducted considering various exogenous variables that can affect local employment, such as the government industrial policies and entrepreneurial infrastructure institutions other than the Partner Squares.

Study on the Acceptability and Effectiveness of an Oral Contraceptive Among Iud Drop-outs in Rural Korea

  • Yang, J.M.;Bang, S.;Song, S.W.;Youn, B.B.
    • Journal of Preventive Medicine and Public Health
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    • v.1 no.1
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    • pp.51-66
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    • 1968
  • During a period of about one year(November '66 to December '67), the Yonsei University College of Medicine conducted a field trial of the oral contraceptive(Ovulen) in order to study its acceptability and use-effectiveness among IUD drop-outs in Koyang county. We can summarize the outstanding findings from this investigation as follows; 1. 61.4% of the IUD drop-outs interviewed (911 women) wanted to use the pill. Most of the reasons for not wanting to use it(352 women) pertained to either use of other contraceptive methods(98) or subfecundity(150) following IUD terminations. Only 83 out of 911 women gave reasons related to the difficulty of obtaining pills. Therefore, we can state that most IUD drop-outs if still in need of a contraceptive methods are in favor of trying the pill, and especially so if this method is conveniently available. 2. The 467 women or 37% of those who terminated IUD use actually visited the clinic for medical screening, and only 11 of them or 2.4% were rejected because of pregnancy and other medical reasons such as cervical erosion, myoma, breast mass, etc. 5.5% or 25 of the 456 women who received the first cycle did not take a single pill during the study period. 3. When we defined those 431 women who accepted and took one or more tablets we found that women over age 30, with 4 or more children, and/or with a higher educational level were the best prospects for recruitment. 4. In accuracy of use, about two thirds of the users started taking the pill on the 5 th day as directed for the first three cycles, but the percentages rose sharply to about 80% in later cycles. Tardiness in starting pill use in the first cycle may have occurred partly because they had to return to the clinic monthly to get each new cycle. Among acceptors who did not quit between cycles, 80 to 90% were regular users, missing two or less tablets in each cycle. 5) More than 60% of the users felt well and sometimes lost their pre-acceptance symptoms. especially dysmenorrhea. However, 27.4% (58 women) had side effects attributable to the pill compund as nausea, vomiting, indigestion, breast tenderness, decreased lactation or breakthrough bleeding. 25.0% (53 women) also complained of medical diseases or symptoms not related to the pill, especially during the first three cycles. However, as the confidence and experience of the client and the field workers grew, the incidence of unrelated medical complaints quickly fell to a lower level in the later cycles. 6. As of the end of this study, on December 31, 1967, 49.2% (212 women) had discontinued the use of the pill for medical reasons as well as for the non medical reasons. Only one case terminated use due to a pregnancy after taking pills. The cumulative continuation rates (by the life table method), were 58.9%, 51.9%, 41.0% at the end of 3 months, 6 months and one year, respectively. These rates are lower than in the U.S. studies. Even when we add the retaking group to the first segment, the continuation rate goes up only about 5% above the first segment rates mentioned above. Possible explanations are different dosages, the newerness of the method and the use of only one point for pill distribution in the country together with a monthly return for cycle 1, 2, 3, and 4-6.

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Effects of Preoperative Continuous Use of Aspirin and Plavix in off-pump Coronary Artery Bypass Surgery (아스피린과 플라빅스의 수술 전 지속적 사용이 무심폐기 하 관상동맥우회술에 미치는 영향)

  • Yi Gijong;Lee Kyo-Joon;Yang Hong-Seok;Ahn Ji-Young;Yoo Kyung-Jong
    • Journal of Chest Surgery
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    • v.39 no.1 s.258
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    • pp.48-55
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    • 2006
  • Background: The benefits of preoperative use of aspirin and plavix in coronary patients have been well documented. Due to their bleeding tendency, there have been many discussions about when to stop the antiplatelet agent before operation. We evaluated the effects of preoperative continuous use of aspirin and plavix in OPCAB patients. Material and Method: 123 patients underwent OPCAB from March, 2004 to Feb., 2005. We divided them into two groups; those who had continuous administration of aspirin and plavix during the preoperative period (n=45, 36.6$\%$) and those who discontinued them at least one day before the operation (n=78, 63.4$\%$). We then compared the platelet count, hemoglobin/hematocrit level, graft patency, postoperative bleeding and related complications, and operation time between the two groups. The patients were also divided into long-term users ($\geq$ 1 month) and short-term users (< 1 month), with the aforementioned factors equally compared. Result: There was no statistical difference between the two groups regarding postoperative bleeding, related complications, graft patency, operation time and mortality. Continuous users showed significantly low platelet levels on immediate post operation (p=0.02), postoperative day (POD) $\sharp$1 (p=0.002) and POD $\sharp$2 (p=0.021), respectively. But there was no difference on POD $\sharp$7. Long-term users showed statistically significant difference in pre- and postoperative platelet count, but none in postoperative bleeding and related complications. Conclusion: Continuous use of aspirin and plavix did not increase postoperative bleeding or related complications. Also graft patency and mortality had no statistical differences in continuous users. We think that there is no need to stop aspirin and plavix before OPCAB.

Experimental Studies on Influence of Foaming Agents on the Properties of Mortar (기포제가 모르터의 제성질에 미치는 영향에 관한 실험적 연구)

  • Sung, Chan-Yong;Hwang, Eun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.27 no.1
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    • pp.46-61
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    • 1985
  • This study was performed to obtain the basic data which can be applied to the use of foaming mortars. The data was based on the properties of foaming mortars depending upon various mixing ratios and addings to compare those of cement mortar. The foaming agents which was used at this experiment were pre-foamed type and mix-foaming type which is being used as mortar structures. The foaming mortar, mixing ratios of cement to fine aggregate were 1:1, 1: 2, 1 : 3 and 1 : 4. The addings of foaming agents were 0.0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% of cement weight. The results obtained were summarized as follows; 1. At the mixing ratio of 1 : 1, the lowest water-cement ratios were showed by foaming mortars, respectively. But it gradually was increased in poorer mixing ratio and decreased in more addition of foaming agent. The water-cement ratios were decreased up to 1. 8~22. 0% by G, 2. 2~24. 1 % by U and 0. 7~53. 1% by J foaming mortar than cement mortar. 2, At the mixing ratio of 1 : 1, the highest bulk densities were showed by foaming mortars, respectively. But, it gradually was decreased in poorer mixing ratio and more addition of foaming agent. The bulk densities were decreased up to 1. 4~20. 7% by G, 2. 3~23. 7% by U and 26. 5~56. 5% by J foaming mortar than cement mortar. Therefore, foaming mortar could be utilized to the constructions which need low strengths. 3. At the mixing ratio of 1:1, the lowest absorption rates were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Specially, according to the absorption rate when immersed in 72 hours, the absorption rates were showed up to 1. 01~1. 24 times by G, 1. 03~1. 58 times by U and 1. 10~5. 91 times by J foaming mortar than cement mortar. It was significantly higher at the early stage of immersed time than cement mortar. 4. At the mixing ratio of 1:1, the lowest air contents were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Air contents were contented up to 4. 0~17. 2 times by G, 5. 2~23. 2 times by U and 23. 8~74. 5 times by J foaming mortar than cement mortar. 5. At the mixing ratio of 1 : 1, the lowest decreasing rates of strengths were showed by foaming mortars, respectively. But, it gradually was increased in poorer mixing ratio and more addition of foaming agent. Specially, the strengths of 28 days were decreased 0. 4~2. 2% than those of 7 days by foaming mortar, respectively. Also, the correlations between compressive and tensile strength, compressive and ending strength, tensile and bending strength were highly significant as a straight line shaped, respectively. 6. The correlations between absorption rate, air content, compressive strength and bulk density, absorption rate, compressive strength and air content were highly significant, respectively. The multiple regression equations of water-cement ratio, bulk density, absorption ate, air content, compressive strength, tensile strength and bending strength were computed depending on a function of mixing ratio and addition of foaming agent. It was highly significant, respectively. 7. At the mixing ratio of 1 : 1, the highest strengths were showed by cement mortar and foaming mortars, by chemical reagents. But, it gradually was decreased in poorer mixing ratio. The decreasing rates of strengths were in order of H $_2$S0 $_4$, HNO$_3$ and HCI, J,U,G foaming mortar and cement mortar. Specially, at the each mixing ratio, each chemical reagent and 3.0% of foaming agent, J foaming mortar was collapsed obviously. Therefore, for the structures requiring acid resistence, adding of foaming agent should be lower than 3.0%.

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A Study on Prevention of Accident in Korean Security Industry (경호산업의 재해예방에 관한 연구)

  • Cho, Han-Bong
    • Korean Security Journal
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    • no.2
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    • pp.259-289
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    • 1999
  • The Security Industry has dynamic working conditions. So this study intends to find the advisable direction for the reduction of accidents. To achieve the aim, the investigation of documents and the examinations of actual proofs have been done to figure the theoretical background and to see the basic knowledge of security industry. The questionnaire was composed of two question sheets to search real data and actual proofs, with making targets of pure security organization and personnel. The one consists of 9 questions to find the scale and extent of security organizations and the population and character of security personnel, and the other 25 questions in 3 major areas to analyze the causes, the frequency rates, the factors, and the condition of accidents. The period of survey was July 15th to October 15th in 1997 by mail/telephone/interview. The questionnaires were efficiently returned from 102 different organizations including the public security groups of Seoul Metropolitan Police Bureau and so on, with the information of 8,222 persons having worked for Korean Security Industry in 1996. So being based on the reality, some meaningful facts were found, and were compared with the national statistics of the Government. This study is made up of 5 chapters : in the 1st chapter the motivation, the object, the method, the direction and the limitation of the approach were presented ,in the 2nd chapter the theoretical background were inferred ; in the 3rd chapter the collected data of accidents in Korean Security Industry were analyzed and explained on the base of the questionnaires , in the 4th chapter the advisable facts connected with preventing accidents were mentioned ; in the last the conclusion were stated. With the replies of 102 different organizations including the information of 8,222 persons in 1996, the main facts found or analyzed through this study are as follows. Firstly, accident is an unpredictable and occasional event. It occurs to man and/or thing, but the frequency rate of accidents in Korean Government and other Institutes has been calculated and evaluated only in the point of the accident related with man. Secondly, the factors of accidents are firstly relevant to the way preventing accidents in Security Industry in Korea. However the frequency rate is academically calculated and evaluated by at once man(population) and hour(time). But the Government has done the rate only by man(population). This can be improper and inaccurate rates. Thirdly, the confused concept of security is used in Korean Government, academic society, corporation and so on. Therefore the detailed formation of the concept is needed for the development of Security Industry in Korea. Fourthly, security organizations can be classified into 'public security(public law enforcement)' and 'private security' according to its identification, and furthermore 'private security' can be divided into 'facilities-guard service', 'body-guard service', and 'patrol service' according to its major role. Fifthly, in the viewpoint of the number of both organization and population,'facilities-guard service' is centered in Korean 'private security'. According to the analyzed results of the questionnaires in this study, the frequency rate of accidents of Korean Security Industry is 0.43(%) totally in 1996 : 'facilities-guard service' 0.54(%), 'body-guard service' 0.12(%), and 'patrol service' 0.21(%) in 'private security', and 'public security' 0.20(%). With regard to the accident frequency rate of organization and population, 'facilities-guard service' is the highest. The accident frequency rate of population in 'facilities-guard service' organization ranges dispersively from 0.20(%) to 11.11(%). Sixthly, the accidented rate of workers having serviced for under one year is 57.6(%). This can mean that the main factor of accidents in Korean Security Industry is the lack of role-understanding and training/education. And another factor can be found on the time of accident occurrence. Many accidents have been occurred on the relaxed points like as just after lunch and morning rush-hour. Lastly, the major advisable facts related to preventing accidents are as follows : The workers who are over fifty years old in 'facilities-guard service' organization need to be educated for preventing accidents ; It is desirable that the training and education to prevent accidents should be practiced in the time of pre-service ; As the style of accidents and the age of the accidented are not same according to major service area('public security' and 'private security' : 'facilities-guard service', 'body-guard service', and 'patrol service'), the plans to prevent accidents must be different and various. However fracture and bruise are general accidents in Korean Security Industry ; Workers must care about traffic accident and violent fall ; It seems that the grouped working with other two persons will reduce accident occurrence possibility rather than individually single working.

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