• 한국지반공학회논문집
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• 제15권2호
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• pp.43-71
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• 1999

본 연구는 하수처리장 슬러지를 사용하여 매립지의 복토재 및 차수재의 건설재료로 개발하기 위하여 수행한 실험의 분석결과이다. 하수슬러지에 그의 지반공학적 물성증진을 위하여 화강토와 화력발전소의 부산물인 플라이애쉬를 주첨가물로 사용하고 부첨가물로 시멘트 및 벤토나이트를 소정의 혼합비율로 섞어서 각각 전단강도 증진과 투수계수 감소효과를 도모하였다. 주재료인 하수슬러지와 첨가재의 혼합비율을 변화시킨 혼합물에 대하여 다양한 실내실험을 수행하여 복토재 및 차수재의 설계기준의 적합성 여부를 조사하였다. 각 주재료, 첨가재, 혼합물의 비중, 입도분석, 액\ulcorner소성한계 실험을 실시하여 기본물성을 구하고 그들이 투수성, 다짐성, 압축성, 전단강도에 미치는 영향에 대하여 분석하였다. 혼합물에 대하여 실내다짐시험을 실시하여 최대건조단위중량과 최적함수비를 구하고 현장 다짐효율성을 평가하였다. 다짐혼합시료에 대하여 변수두 투수시험을 실시하여 투수계수를 구하는 한편 변수두 투수시험을 하중제어식 압밀시험중에 병행 실시하여 그들의 압밀정수 및 투수계수를 측정하였다. 슬러지의 장기적 안정성과 관련하여 크리프실험을 변수두 투수시험과 함께 실시하였다. 한편, 한달간을 부패시킨 다짐시료에 대하여 투수시험을 실시하여 슬러지내 유기물질 부패에 의한 투수계수에 미치는 영향에 대하여 고찰하였다. 슬러지에 화강토, 플라이애쉬, 벤토나이트를 일정비율로 섞은 혼합물에 대하여 직접전단시험을 실시하여 전단강도정수를 구하였다. 시멘트와 혼합한 슬러지에 대하여 일축압축 강도시험을 실시하여 혼합비와 재령기간에 따른 압축강도 변화를 분석하였다. 한편, 다짐혼합시료에 대하여 CBR시험을 수행하여 그들의 주행성에 대한 평가를 실시하였다. 이와 같은 다양한 실험결과를 종합분석하여 매립지의 차수재 및 복토재로서 사용조건 만족여부를 검토하였다.

• 농업과학연구
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• 제14권1호
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• pp.98-133
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• 1987

The mechanical and rheological properties of agricultural materials are important for engineering design and analysis of their mechanical harvesting, handling, transporting and processing systems. Agricultural materials, which composed of structural members and fluids do not react in a purely elastic manner, and their response when subjected to stress and strain is a combination of elastic and viscous behavior so called viscoelastic behavior. Many researchers have conducted studies on the mechanical and rheological properties of the various agricultural products, but a few researcher has studied those properties of rice plant, and also those data are available only for foreign varieties of rice plant. This study are conducted to experimentally determine the mechanical and the rheological properties such as axial compressive strength, tensile strength, bending and shear strength, stress relaxation and creep behavior of rice stems, and grain detachment strength. The rheological models for the rice stem were developed from the test data. The shearing characteristics were examined at some different levels of portion, cross-sectional area, moisture content of rice stem and shearing angle. The results obtained from this study were summarized as follows 1. The mechanical properties of the stems of the J aponica types were greater than those of the Indica ${\times}$ Japonica hybrid in compression, tension, bendingand shearing. 2. The mean value of the compressive force was 80.5 N in the Japonica types and 55.5 N in the Indica ${\times}$ Japonica hybrid which was about 70 percent to that of the Japonica types, and then the value increased progressively at the lower portion of the stems generally. 3. The average tensile force was about 226.6 N in the Japonica types and 123.6 N in the Indica ${\times}$ Japonica hybrid which was about 55 percent to that of the Japonica types. 4. The bending moment was $0.19N{\cdot}m$ in the Japonica types and $0.13N{\cdot}m$ in the Indica ${\times}$ Japonica hybrid which was 68 percent to that of the Japonica types and the bending strength was 7.7 MPa in the Japonica types and 6.5 MPa in the Indica ${\times}$ Japonica hybrid respectively. 5. The shearing force was 141.1 N in Jinju, the Japonica type and 101.4 N in Taebaeg, the Indica ${\times}$ Japonica hybrid which was 72 percent to that of Jinju, and the shearing strength of Taebaeg was 63 percent to that of Jinju. 6. The shearing force and the shearing energy along the stem portion in Jinju increased progressively together at the lower portions, meanwhile in Taebaeg the shearing force showed the maximum value at the intermediate portion and the shearing energy was the greatest at the portion of 21 cm from the ground level, and also the shearing strength and the shearing energy per unit cross-sectional area of the stem were the greater values at the intermediate portion than at any other portions. 7. The shearing force and the shearing energy increased with increase of the cross-sectional area of the rice stem and with decrease of the shearing angie from $90^{\circ}$ to $50^{\circ}$. 8. The shearing forces showed the minimum values of 110 N at Jinju and of 60 N at Taebaeg, the shearing energy at the moisture content decreased about 15 percent point from initial moisture content showed value of 50 mJ in Jinju and of 30 mJ in Taebaeg, respectively. 9. The stress relaxation behavior could be described by the generalized Maxwell model and also the compression creep behavior by Burger's model, respectively in the rice stem. 10. With increase of loading rate, the stress relaxation intensity increased, meanwhile the relaxation time and residual stress decreased. 11. In the compression creep test, the logarithmic creep occured at the stress less than 2.0 MPa and the steady-state creep at the stress larger than 2.0 MPa. 12. The stress level had not a significant effect on the relaxation time, while the relaxation intensity and residual stress increased with increase of the stress level. 13. In the compression creep test of the rice stem, the instantaneous elastic modulus of Burger's model showed the range of 60 to 80 MPa and the viscosities of the free dashpot were very large numerical value which was well explained that the rice stem was viscoelastic material. 14. The tensile detachment forces were about 1.7 to 2.3 N in the Japonica types while about 1.0 to 1.3 N in Indica ${\times}$ Japonica hybrid corresponding to 58 percent of Japonica types, and the bending detachment forces were about 0.6 to 1.1 N corresponding to 30 to 50 percent of the tensile detachment forces, and the bending detachment of the Indica ${\times}$ Japonica hybrid was 0.1 to 0.3 N which was 7 to 21 percent of Japonica types. 15. The detachment force of the lower portion was little bigger than that of the upper portion in a penicle and was not significantly affected by the harvesting period from September 28 to October 20. 16. The tensile and bending detachment forces decreased with decrease of the moisture content from 23 to 13 percent (w.b.) by the natural drying, and the decreasing rate of detachment forces along the moisture content was the greater in the bending detachment force than the tensile detachment force.

• 한국의류산업학회지
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• 제2권3호
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• pp.253-264
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• 2000

The purpose of this study was to examine the thermal comfort characteristics of the garments for school, textile and bank worker's uniform. The garments selected for this study were frequently used in Taegu area in terms of design and material used for making garments by the survey for the study The human subject tests were performed to determine the thermal comfort characteristics of garments including thermal, humidity, and wearing sensation and the data were analysed statistically. The results of the study were as follows: 1. According to the result of the survey jacket was mostly used as a school uniform for both male and female high school students. The survey showed that 93% of male students wore 'neck T-shirts' and dimensional fitness for the school uniform got suitable at 2~3 grade high school students. In terms of human subject tests, most students rated 'uncomfortable' in wearing sensation of their school uniform. One of this reason was due to the humidity sensation and air velocity sensation. Level of significance of the thermal sensation for gender difference was higher in hands and feet of the subjects than in chest and thigh of them. 2. According to the result of the survey jacket with zipper was mostly used as a textile worker's uniform. The result of the survey indicated that some textile workers are wearing their inner wear (38.7% for upper and 46.6% for lower). In the human subject tests, about 50% of subjects rated 'comfortable to slightly comfortable' for wearing sensation of the textile worker's uniform. It showed that the female subjects of the humidity sensation was rated higher than the male subjects of the humidity sensation, while the male subjects of the thermal sensation was rated higher than the female subjects of the thermal sensation. There was a closer correlation with the subjective thermal sensation for textile worker's uniform in center parts of the subjects such as back and waist than exposed parts. 3. The result of the survey showed that 70% and 23% of the female banker uniform were blouse and jacket, respectively and 75% and 25% of the male banker uniform were jacket and T-shirt, respectively. All interviewee rated trousers and skirts that were used for their lower. 4. The result indicated that 50% male and 67.7% female subjects for the banker uniform rated 'slightly comfortable for the comfort' sensation. 50% male subjects rated 'neutral' and about 50% female subjects rated 'slightly warm to neutral' for the thermal sensation. In addition, The result showed that 75% male subjects for both upper and lower rated 'neutral' for the humidity sensation and also 75% female subjects rated 'neutral to slightly dry'. Thus, there was no significant different between gender. 5. In the thermal sensation of the subjects for the banker's uniform by parts, 50% subjects rated 'neutral' for their body parts, including head, neck, back, waist, hip, lower arm, and thigh. The extremely cold parts were hands and feet for both male and female subjects.

• 대한치과보철학회지
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• 제47권2호
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• pp.148-155
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• 2009

연구목적: 최근에는 금속도재관의 심미적 문제로 심미성과 강도가 개선된 코아용 도재 및 지르코니아를 이용한 전부도재관 시스템에 관심이 증가되고 있다. 특히 금속과 유사한 강도를 가지면서 금속의 비심미성을 극복할 수 있는 지르코니아를 이용한 보철물의 제작이 국내외에서 많이 이뤄지고 있다. 하지만 CAD/CAM 시스템으로 제작되는 여러 종류의 지르코니아를 이용한 전부도재관의 적합도에 대한 임상 연구는 부족한 실정이다. 다양한 CAD/CAM 시스템 중 Procera, Cerec inLab, Lava에 의해 제작된 지르코니아를 이용한 전부도재관의 변연 적합도와 내면 적합도를 측정하여 이를 전통적인 방식으로 주조된 금속 도재관의 적합도와 비교 평가해 봄으로써 임상 적용에 참고 자료로 활용하고자 한다. 연구 재료 및 방법: 본 연구를 위해 하악 우측 제2소구치에 해당하는 레진치를 삭제하여 인상채득 후, 금속 주모형을 제작하였다. 금속 주모형의 40개의 인상을 채득 후 각 시스템마다 10개씩 총 40개의 crown을 제작하였다. 금속도재관은 전통적인 방식으로 제작하였고 Procera, Lava, Cerec inLab crown은 zirconia core를 이용하여 CAD/CAM 시스템으로 제작하였다. 수직 변연 오차와 내면 간격을 각 그룹마다 금속 주모형에 시멘트 접착 없이 측정하였다. 그 결과는 oneway ANOVA와 Tukey's HSD test로 통계 내었다. 결과: 수직 변연 오차는 금속도재관이 $50.6{\pm}13.9{\mu}m$, Procera crown이 $62.3{\pm}15.7{\mu}m$, Lava crown이 $45.3{\pm}7.9{\mu}m$, Cerec inLab crown은 $71.2{\pm}2.0{\mu}m$로 측정되었다. 내면 간격은 금속도재관이 $52.6{\pm}10.1{\mu}m$, Procera crown이$161.7{\pm}18.5{\mu}m$, Lava crown이 $63.0{\pm}10.2{\mu}m$, Cerec inLab crown이 $73.7{\pm}10.7{\mu}m$로 측정되었다. 변연 적합도 측면에서 볼 때 Procera crown, Lava crown, Cerec inLab 그리고 전통적인 금속도재관은 임상적으로 받아들일 수 있는 적합도 범위($120{\mu}m$) 내에 있었다. 내면 적합도 측면에서 볼 때 Procera crown을 제외한 Lava crown, Cerec inLab, 금속도재관은 임상적으로 받아들일 수 있는 적합도 범위($140{\mu}m$) 내에 있었다.

• 대한치과보철학회지
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• 제47권2호
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• pp.206-214
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• 2009

연구목적: 하악 우측 제1, 2 대구치가 결손된 Kennedy 분류 II급 증례에서 임상적으로 적용할 수 있는 편측 유리단 가철성 국소의치의 종류에 따른 응력 분포 양상을 비교하는 것이다. 연구 재료 및 방법: Kennedy 분류 II급 증례의 광탄성 모형에서 클라스프를 이용한 국소의치, 코너스 치관을 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치, 탄성 레진을 이용한 국소의치를 편측성으로 제작하였다. 응력 동결로에서 응력 주기에 맞춰 각 국소의치의 제1 대구치 중심와에 6 kg의 수직하중을 가하면서 응력을 동결하였다. 광탄성 모형을 절단하여 만든 시편을 광탄성 실험 장치로 광탄성 등색선의 흑백 무늬를 관찰하고 디지털 카메라로 촬영하였다. 촬영된 사진에서 8개의 측정점을 정하여 육안으로 무늬차수를 계측하고 비교하였다. 결과: 각 절단 시편의 최대 무늬차수와 하중점 직하방의 잔존 치조제에 발생한 무늬차수는 탄성 레진을 이용한 국소의치, 클라스프를 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치, 코너스 치관을 이용한 국소의치 순으로 높게 관찰되었다. 제2 소구치 치근단에 발생한 무늬차수는 클라스프를 이용한 국소의치, 탄성 레진을 이용한 국소의치, 코너스 치관을 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치 순으로 높게 관찰되었다. 결론: 코너스 치관을 이용한 국소의치가 수직하중시 지대치 주위 치조골과 잔존 치조제에 대하여 응력을 가장 균형있게 분산시켰고, 탄성 레진을 이용한 국소의치는 지대치보다 잔존 치조제의 상태가 더 양호한 경우에 적용 가능할 것이다.

• 대한치과보철학회지
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• 제46권2호
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• pp.169-174
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• 2008

목적: 치과 임플랜트 주위의 변연골 변화는 임플랜트의 기능적인 유지 뿐만 아니라 심미적 성공을 위해서도 중요하다. 변연골의 유지를 위한 임플랜트 디자인이 연구되고 있다. 이번 예비 연구는 두 종류의 external hex implant 시스템에서 임플랜트의 상부 미세 나사산이 변연골 변화량에 미치는 영향을 평가하고자 한다. 재료 및 방법: 총 24명의 환자를 대상으로 $Br{{\aa}}nemark$ 임플랜트 식립군 (1군, 거친 표면 임플랜트, 20개)과 원플란트 임플랜트 식립군 (2군, 미세나사산을 가진 거친 표면 임플랜트, 20개)으로 분류하였다. 기준 시점 (임플랜트 부하)과 부하를 가한 1년 뒤 임상적, 방사선학적 검사를 시행하였다. UTHSCSA Image Tool을 이용하여 임플랜트-보철 경계부로부터 변연골 높이 변화량으로 계측하였다. 계측치는 SAS 프로그램을 이용하여 three-level ANCOVA로 통계처리 하였다. 결과: 기준 시점과 비교하여 1년 기능 후, 두 그룹 간의 변연골 소실 변화량에 있어서 통계학적으로 유의한 차이가 있었다 (P<0.05). 1군의 평균 변연골 높이 변화량은 $0.83{\pm}0.31mm$, 2군에 있어서는 $0.44{\pm}0.36mm$ 이었다. 미세나사산을 가진 거친 표면 임플랜트가 미세나 사산을 가지지 않은 거친 표면 임플랜트 보다 더 적은 변연골 소실 변화량을 보였다. 결론: 미세나사산을 가진 거친 표면 임플랜트가 기능적 부하 후 변연골 높이를 유지하는데 있어 더 유리한 디자인으로 보인다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.61-62
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• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.

• 한국식품과학회지
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• 제37권2호
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• pp.233-240
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• 2005

본 연구에서는 산채식물들을 이용한 새로운 기능성 소재의 개발에 우선하여 생산량과 소비량이 비교적 양호한 산채류 7종 즉, 물엉겅퀴, 쇠무릅, 울릉미역취, 섬고사리, 서덜취, 눈개승마 및 쇠비름을 선정하여 각 부위별 메탄올추출물을 제조한 후 이들의 항산화 활성을 검색하였다. 총 폴리페놀성 화합물의 함량은 $16.74-130.20{\mu}g/mg$으로 다양하게 나타났다. 섬고사리 잎과 울릉미역취 뿌리는 DPPH 와 ABTS+ 소거활성에서 각각 13.20과 $14.91{\mu}g/mL$. 43.93과 $29.08{\mu}g/mL$의 $RC_{50}$ 값을 보여 가장 높은 소거활성을 나타냈으며 또한 폴리페놀의 함량에 비례하여 소거활성이 증가하여 폴리페놀 함량과 free radical 소거활성은 깊은 연관성이 있음을 알 수 있었다. $H_{2}O_{2}$에 대한 소거활성은 섬고사리 잎과 뿌리 및 울릉미역취 뿌리에서 각각 72.83, 89, 99.62%로 높은 활성을 나타냈고 이러한 결과 역시 폴리페놀 함량과의 연관성을 나타냈다. 산채나물 추출물을 이용하여 linoleic acid에 대한 과산화 억제 효과를 ferric thiocyanate법으로 살펴본 결과, $100{\mu}g/mL$의 처리농도에서 모두 90% 이상의 산화억제 효과를 보였고, $10{\mu}g/mL$ 처리 농도에서는 울릉미역취 뿌리와 씨 그리고 서덜취 잎에서 각각 83.4, 87.4, 79.8%의 산학억제 효과를 보였다. Hydroxy radical에 의한 2-deoxy-D-ribose의 산화억제 효과는 $100{\mu}g/mL$의 처리농도에서 쇠무릎 잎과 씨, 물엉겅퀴 씨, 울릉미역취 씨는 116.9, 84.8, 94.3, 93.9%로 높은 저해율을 보였다. 것으로 나타났다. 그러므로 감마선 조사 및 저온저장($10^{\circ}C$)은 김밥재료 뿐만 아니라 김밥의 미생물 제어에 효과적인 것으로 확인되었다.와 비례하는 경향을 나타내었다. 또한 FA-swelling mica의 중금속 이온의 선택성은 Pb>Cu>Cd$\geq$Zn 순으로 나타났다.지 않았다.l years and a new type of transfer crane has been developed. Design concepts and control methods of a new crane will be introduced in this paper.and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basis of the simplified model, the simulation was performed and the results could be confirmed by the experiments under various conditions.뢰, 결속 등 다차원의 개념에 대한 심도 깊은 연구와 최근 제기되고 있는 이론의 확대도 필요하다. 마지막으로 신뢰와 결속에 영향을

• 한국식품과학회지
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• 제37권2호
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• pp.183-188
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• 2005

순수 methanol을 cd-solvent로 첨가하였을 때 소량의 수율을 얻을 수 있었던 반면 methanol에 물을 첨가하여 수용액을 조제한 후 각각 첨가하였을 때 co-solvent의 극성도 증가에 비례하여 수율이 현저하게 증가하였다. 60% methanol을 첨가하였을 때 수율이 가장 높았으며 순수 methanol 첨가구와 비교하여 luteolin이 5.9배, quercetin이 4.1배, apigenin이 7.8배 가량 증가하였다. Co-solvent에 citric acid를 농도별로 첨가한 결과 첨가량 1%까지는 추출수율이 농도 비례적으로 증가하는 경향을 나타내어 대조구에 비해 대략 luteolin이 14.64mg/100g, quercetin이 10.17mg/100g, apigenin이 2.4mg/100g의 유의적인 증가율을 보였으나 그 이상의 농도에서는 소량 감소하는 경향을 보였다. 한편 산을 첨가한 모든 조건에서 대조구보다 높은 수율을 얻을 수 있었다. 추출수율이 가장 우수하였던 citric acid가 1% 첨가된 60% aqueous methanol을 co-solvent로 초임계상태에 첨가하였을 때 공정압력이 100bar에서 200ber로 증가함에 따라 추출수율이 비례적으로 증가하였으나 250bar 이상에서는 감소하는 경향을 나타내었다. 온도에 따라서는 $40^{\circ}C$에서 $50^{\circ}C$까지는 증가하는 경향을 보이다 이상의 온도에서는 오히려 감소하였다. 추출 시간의 증가와 더불어 추출 수율은 유의적으로 증가하다가 60분일 때 최대값을 보였으며 90분 이상의 추출시간에서는 추출수율이 거의 일정해졌다. $CO_{2}$ 대비 cosolvent를 15(0.3mL/min)% 첨가하였을 때 최대 추출수율을 보였으며 25% 이상의 첨가구에서는 첨가량은 증가하였으나 수율은 감소하는 경향을 보였다. 것으로 나타났다. 그러므로 감마선 조사 및 저온저장($10^{\circ}C$)은 김밥재료 뿐만 아니라 김밥의 미생물 제어에 효과적인 것으로 확인되었다.와 비례하는 경향을 나타내었다. 또한 FA-swelling mica의 중금속 이온의 선택성은 Pb>Cu>Cd$\geq$Zn 순으로 나타났다.지 않았다.l years and a new type of transfer crane has been developed. Design concepts and control methods of a new crane will be introduced in this paper.and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basis of the simplified model, the simulation was performed and the results could be confirmed by the experiments under various conditions.뢰, 결속 등 다차원의 개념에 대한 심도 깊은 연구와 최근 제기되고 있는 이론의 확대도 필요하다. 마지막으로 신뢰와 결속에 영향을

• 지역사회간호학회지
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• 제12권3호
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• pp.795-814
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• 2001

To evaluate the effect of sex education on middle school students' access to the obscene online computer and video film contents. 154 students were selected as experimental group. and 154 students were selected as control group, sampled randomly from Andong. Kyungbook, Korea. An analysis was performed. A non-equivalent control group pre test-post test research design was used. The data were collected from April 2nd to April 19th. 2001. A pre-survey was done on general characteristics and the condition of accessing obscene online computer and video film contents on both experimental and control group. From the survey results information. sex education contents were put together. The researcher organized 3 ready-made sex education program and explained to the four school health nurses about the ready-made sex education program step by step and they educated their selected students with three classes of 45 minutes lecture. Two weeks after the last lecture, a post-test was conducted. Four weeks from the last lecture, another post-test was conducted. The existing studies by Choi Yongseon(1998) and Kim Hyeok(1998) were reviewed and two professors in the department of community health nursing advised on the study questionnaire writing. An SPSS Win 10.0 was used. The data of respondents' general characteristics were analyzed using frequency and percentage. $X^2$ test was used to verify the homogeneity of the experimental group and the control group. Repeated Measures ANOVA was used to find out whether sex education had an effect on the awareness of obscene online computer and video film contents and under-age prostitution through the online computer networks. and time and frequency of access to the obscene online computer and video film contents. The results of the study are as follow. 1. The results of the verification of homogeneity between the experimental group and the control group showed that there was no significant difference between the experimental group and the control group. 2. The first hypothesis, 'the experimental group which received sex education would have a higher level of awareness of accessing obscene contents than the control group which did not receive the education' was supported at p<0.0001. 3. The second hypothesis. 'the experimental group which received sex education would have a higher level of awareness of underage prostitution on computer networks than the control group which did not receive the education' was supported at p<0.05. 4. The third hypothesis, 'the experimental group which received sex education would spend time less accessing obscene video and computer contents than the control group which did not receive the education' was rejected at p>.05. 5. The 4-1 hypothesis. 'the experimental group which received sex education would access obscene computer contents less frequently than the control group which did not receive the education' was supported at p<0.0001. 6. The 4-2 hypothesis, 'the experimental group which received sex education would access obscene video contents less frequently than the control group which did not receive the education' was supported at p<0.0001. In conclusion, a systematic step-by-step sex education program should be developed to protect middle school students from the harmful online computer and video film access. An effective teaching material for sex education should be prepared to decrease middle school students' access to obscene online computer and video film contents.