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      • Development of a Mobile Application, "Wild Flowers of Bukhansan National Park (version 1.0)", for Identification of Plants in Bukhansan National Park

        Kim, Sang-Tae,Lee, Seung-Yeon,Kim, Seung-Chul,Byun, Hye-Won,Lee, Sang-Tae,Kim, Mu-Yeal,Hong, Seok-Pyo,Chung, Young-Jae,Park, Ki-Ryong,Lee, Chung-Hee,Lee, Joong-Ku,Heo, Kyeong-In,Lee, Ji-Ye,Lee, Eun-Je National Science Museum of Korea 2011 Journal of Korean nature Vol.4 No.3

        We developed the educational purpose mobile application, named "Wild Flowers of Bukhansan National Park (version 1.0)", aiming for easy identification of wild flowers for students and visitors in the park. When visitors find a flower or part of plant in the park, visitors can search for its name utilizing the pictures and characters provided in their own smartphone mobile devices or tablet PCs. The application provides pictures of wild flowers in the park and character-based searching system based on 12 diagnostic features (e.g., growth form, leaf arrangement, flower symmetry, petal color, petal number, sepal number, etc). We adopted the complete floristic survey of Chung and Lee (1962) and added species that we confirmed their distribution in the park during the development of this application. In summary, number of vascular plants in this park was estimated to be 428 taxa including 100 families, 280 genera, 327 species, 1 subspecies, 50 varieties, and 5 formas. We provided a total of 588 pictures representing 358 taxa and each taxon includes multiple pictures in many cases. Included identification quizzes can be an efficient educational tool as well as fun activity for students and visitors who are learning plant species in Korea. Our next step will include GPS function in the application for indicating visitor's location and for providing previously reported sites of the species that we interested in the map of the park. The future application which includes GPS function will be a valuable tool for the monitoring of rare plants, plant researches related to the climate changes, etc. We currently provide Korean iPhone version only, and English version and both of android versions will be serviced soon.

      • 오픈케이슨기초의 침하촉진을 위한 AIR-JET 공법의 적용성 분석

        박진원,류제천,임희대 忠南大學校 産業技術硏究所 2003 산업기술연구논문집 Vol.18 No.2

        By air jet method, settlement time was much decreased and settlement was reached even to the depth which conventional method could not. The friction reduction increased more than 20 to 30%. In addition to this merits, air jet method can make caisson settlement without separating loading or increasing dead loads. By this method, size of caisson sections can be reduced for resulting in tremendous cost reduction. Also, caisson damage by blasting can be prevented with this method.

      • KCI등재후보

        Polyphosphate가 연조직 창상 치유에 미치는 영향에 관한 연구

        박기범,류동목,이진용,신제원 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.3

        Polyphosphate has been used as a food additive. It has been approved the use of PolyP to the products as a safe additive. In other study, PolyP seems to has an ability of promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and/or by increasing osteoinductivity of the damaged bone tissue. So we performed this study in order to evaluate the effect of polyphosphate on the dermal defect healing in critical-sized defect wound. Using welder and blade, a 1㎝ diameter sized burn-defect and rectangular excisional-defect was prepared in the thigh of each Sprague-Dawley rats. Then defect areas were applied topically with distilled water(DW), 0.01% orthoposphate(Pi), or 0.01% polyP75. The application of these materials was continued for seven days. The rats, which had burn wounds, were sacrificed at week 1 and 2. the other goups, which had excisional wounds, were sacrificed at day 3, week 1, 2, and 4. the specimens of the defect were prepared, stained with H&E, and examined under the microscope. Dermal defect healing capacity of polyP75 was also examined by observaing cellular activity of periodontal cells using MTT assay. The results were as follows. PolyP75 at the concentrations of 0.01% increased the MTT activity of periodontal cells by 154.1%. a pathohistologic findings of burn wound with polyP75 showed a faster epidermal healing and more profound maturation in dermis than those of other groups. In excisional wound, compare with other groups, tissue maturity and density of matrix in dermis were much enhanced in the polyP75 groups.

      • 시멘트 콘크리트의 건조수축균열 특성

        박제선,윤경구,이주형,김태환,정원경 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

        콘크리트는 본질적으로 인장강고와 휨강도가 약하며 취성적 성질을 나타내는 결점을 가지고 있으므로 이를 보강할 목적으로 콘크리트에 섬유를 혼입한 섬유보강 콘크리트가 크게 각광받고 있다. 특히 폴리프로필렌 섬유보강은 모르타르 및 콘크리트가 건조나 동해에 의해 수축될 때 구속에 의해 발생되는 인장응력 및 균열을 제어하고 인성의 증가와 충격, 마모, 피로에 대한 저항성, 내구성을 증대시키는 장점을 가지는 것으로 보고 되고 있다. 1축으로 구속된 건조수축의 구속으로 인한 조강형 콘크리트의 잔류응력을 선형모델을 이용하여 예측할 수 있었고 조강형 콘크리트에 섬유보강으로 인한 건조수축 제어효과는 일반큰코리트에 비해 효과가 매우 큰 것으로 나타났다. 따라서 폴리크로필렌 섬유의 혼입으로 인해 콘크리트의 균열제어가 가능하며, 균열 폭이 큰 균열보다는 많은 미세 균열을 유도하는 것을 알 수 있었다. 섬유보강 조강형 큰크리트의 동결융해저항특성은 거의 동해의 손상을 받지 않으며 좋은 내구성을 유지하고 있는 것으로 나타났다. 이는 불규칙하게 배향된 섬유가 공극수의 이동을 효과적으로 제어함으로써 메트릭스 내의 팽창압으로 인한 파괴를 최대한 줄였기 때문이라고 보여진다. 표면손상과 박리저항에 매우 우수하며 저항성을 증진시키는 효과가 뛰어남을 확인할 수 있었다. 따라서, 내구적 측면의 유지, 보수에 있어서도 섬유보강은 그 효과가 큰 것으로 나타났다. To improve the brittle nature of concrete, discrete fibers can be adapted in concrete. Since polypropylene fiber has many advantages in many points on its chemical stability and good durability, its usages have been increased gradually. It has been reported than polypropylene fibers can not only control restrained tensional stresses and cracks, but also increase toughness, resistance to impact, corrosion, fatigue, and durability. Although the polypropylene fiber reinforced concretes with ordinary cement have been studied so much, those with very early strength concretes have not studied at all. Therefore, it is necessary to initiate and conduct the researches for the polypropylene fiber reinforced very early strength concretes which has enough workability and durability. This study of polypropylene fiber reinforced very early strength concrete focused on the investigation each material's effect into strength development with analysis of restrained shrinkage properties with one-dimensional concrete members. The results showed that more optimized mixture combinations could be selected in very early strength concrete by incorporating polypropylene fibers, keeping in same strength levels at urgent repair works. The formation of needle-shape ettringite helps the early strength development, specially at flexural and this enables the repaired concrete structures or pavements to be opened to traffic after 3 hours of concrete placement. A residual stress of early strength concrete caused by one-dimensional restrained drying shrinkage was predicted from linear model. the control of shrinkage crack by fiber reinforcement at early strength concrete was better than that of ordinary portland cement concrete because of bridging effect of fiber at early age and resulting of more hair cracks rather than fewer wider cracks. As a results, this dissertation clearly validated the fiber reinforcement on the strength development and durability of polypropylene fiber reinforced very early strength concrete, and characteristic of restrained shrinkage. The proposed optimized concrete mixtures might be satisfactory applied at the repair works in fields, because of its durability and crack control capacity against freeze-thaw and contraction at early age, respectively.

      • 골다공증 진단에 피부 두께의 임상적 유용성 평가

        박원근,최민주,김호찬,조성제,박전홍 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

        The study was carried out to examine how much clinically useful was the skin thickness in diagnosis of osteoporosis. The project was to look into not only the presumption that patients with osteoporosis have the skin loss at the similar rate of the reduction in the collagen content of the bone but also the correlation between the collagen content and the skin thickness. The skin thickness was measured on the dorsal hand(right) of the patients using an ultrasonic technique with a 20 MHz focused ultrasonic transducer. Measurements of the bone density of the patients were made on both the lumbar spine (L2-4) and the femoral neck using Dual­Energy X­ray Absorptionmeter(DEXA, Norland). An ultrasonic bone densitometer(Mark 6000, Medison Co. Korea) was taken to measure the speed of sound (SOS) on the calcaneus. It was observed that there were some degrees of correlation between the bone density obtained by the DEXA and the SOS of the calcaneous (P<0.01). There was no evidence that the skin thickness was correlated with the DEXA produced bone density and ultrasonically measured SOS.

      • Girder의 강성을 고려한 복합 재료 교량 상판의 구조 거동

        원치문,박제선,이정호,심도식 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

        Many of the bidge and building floor systems, including the girders and cross-beams, also behave a similar special orthotropic plates. Such plates are subject to the concentrate masses in the form of traffic loads, or the test equipments such as the accelerator in addition to their own masses. Analysis of such problems is usually very difficult. Most of the bridge slabs on girders have large aspect ratios. Finite difference method is used for this purpose, in this paper. The reuslt is compared with that of the beam theory.

      • KCI등재

        주산기 백서에서 혈중 에스트로겐 농도와 공간 기억력과의 상관관계

        박민성,박제민,신성현,한귀원,김명정,김성곤 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.5

        Objectives : This study was designed to find possible effect of pregnancy and parturition on spatial memory, especially in relation to levels of estrogen during the third trimester and postpartal period in rats. Methods : 25 female Sprague Dawley rats were divided into pregnant group (N= 14) and control group (N= 11). Changes in spatial memory during 6 weeks including third trimester and postpartal period were measured using Morris water maze. Time to reach the platform in the maze was indicator of spatial memory. Serum estrogen level was measured on 1 week before delivery, postpartal day 1, and day 14. Results : Both groups showed gradual improvement in performance by trial days and weeks, but no significant difference was found between the two groups. However in the third trimester, pregnant group showed a trend of less achievement on 3 days of learning than control group. Serum estrogen levels did not differ significantly between groups over the 6 weeks of period. However there was positive correlation between serum estrogen level on postpartum day 1 and time to reach platform on postpartum week 2, and negative correlation between estrogen level on postpartum day 14 and latency to the platform on postpartum week 5. Conclusion : These results imply that changes in the serum estrogen level may have dual effects on the spatial learning in peripartal period. It is suggested that decline in cognitive function might occur either by failure of rapid decrease of estrogen, immediately after parturition, or retarded restoration of estrogen in later postpartal period.

      • 원심모형시험을 이용한 모래다짐말뚝 시공지반의 호안제체 사면안정에 관한 연구

        朴鎔遠,柳完圭,白寅哲,金濟奎 명지대학교 산업기술연구소 2008 産業技術硏究所論文集 Vol.27 No.-

        Centrifuge modelling tests with embankment model on sand-clay composite soils(a type of soil which sand compaction piles are established) at the 15.5 and 20% replacement ratio(a_(s)) and with/without geotextile were performed to comprehend the effect of a_(s), and geotextile on slope stability of embankment From the test results, sand-clay composite soils at the 15.5 and 20% replacement ratio(a_(s)) are safety for slope failure(circular slip) and a geotextile reinforced model is better than a non-reinforced model on overall settlement and upheaval of ground surface in front of embankment.

      • 鋼管多段 Grouting 工法의 Tunnel 補强效果에 關한 硏究

        박진원,류체천,김송만,박춘수 충남대학교 산업기술연구소 2001 산업기술연구논문집 Vol.16 No.1

        When Umbrella Arch Method is applied in construction of the first Ok-chon tunnel which have soft ground zone or fractured zone, the result as finite element analysis method, the PENTAGON-2D, is following. 1)There is little effect in bottom displacement due to side wall reinforcement, but side wall displacement decrease 50%. 2)Before reinforced by Umbrella Arch Method, rockbolt axial stress is 16 ton which exceed allowed axial stress, however after reinforced, that is about 5.5ton in up and down path, therefore rockbolt axial stress after reinforced is safe. 3)In shotcrete, compression stress decrease average 65% and shearing force and bending moment is decrease more than average 65%. hence shotcrete has great effect on ground reinforcement in side wall. 4)Umbrella Arch Method was proven as assistant method in fractured zone, but in long term stability, judging the fact that bottom displacement is slightly great, the tunnel invert is continued. Or bottom must be reinforced with reinforced with reference to field measurement data in excavation.

      • 첨가질량이 존재하는 변단면 4변고정 적층복합판으 진동해석

        박제선,김경진,원치문,심도식 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

        A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. This method has been developed for two-dimensional problems including the laminated composite plates and was proved to be very effective for the plates with arbitrary boundary conditions and irregular sections. In this paper, the result of application of this method to the clamped composite plates with non-uniform cross-section and with attached point mass/masses is presented.

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