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        검색결과 12

        1.
        2022.10 구독 인증기관·개인회원 무료
        Dose-rate monitoring instruments are indispensable to protect workers from the potential risk of radiation exposure, and are commonly calibrated in terms of the ambient dose equivalent (H*(10)), an operational quantity that is widely used for area monitoring. Plastic scintillation detectors are ideal equipment for dosimetry because of their advantages of low cost and tissue equivalence. However, these detectors are rarely used owing to the characteristics caused by low-atomic-number elements, such as low interaction coefficients and poor gamma-ray spectroscopy. In this study, we calculated the G(E) function to utilize a plastic scintillation detector in spectroscopic dosimetry applications. Numerous spectra with arbitrary energies of gamma rays and their H*(10) were calculated using Monte Carlo simulations and were used to obtain the G(E) function. We acquired three different types of G(E) functions using the least-square and first-order methods. The performances of the G(E) functions were compared with one another, including the conventional total counting method. The performance was evaluated using 133Ba, 137Cs, 152Eu, and 60Co radioisotopes in terms of the mean absolute percentage error between the predicted and true H*(10) values. In addition, we confirmed that the dose-rate prediction errors were within acceptable uncertainty ranges and that the energy responses to 137Cs of the G(E) function satisfied the criteria recommended by the International Commission.
        2.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Asthma is a chronic inflammatory disease characterized by recurring symptoms, airflow obstruction, and bronchial hyper-responsiveness. The onset of asthma for most patients begins early in life, and current asthma treatment with anti-inflammatory agents can have adverse effects, eventually leading to impaired quality of life. In the pathogenesis of asthma, macrophages and basophils play a vital role during progression. Macrophages not only induce inflammation by secreting inflammatory cytokines but also promote DNA damage and mucus production through nitric oxide (NO) production. Basophils enhance eosinophil recruitment and aggravate asthma through the FcεRIα receptor with high affinity for histamine and IgE. Therefore, in this study, we investigated whether the activation of macrophages and basophils is suppressed by the individual extracts of 28 natural products. RAW 264.7 cells (mouse macrophages) were treated with the natural products in LPS, and 4 natural product extracts resulted in decreased NO production. In β-hexosaminidase assay using RBL-2H3 cells (rat basophils), 19 natural product extracts decreased β-hexosaminidase production. In NO production and β-hexosaminidase assay using macrophages and basophils, 3 natural product extracts (Plantago asiatica, Centella asiatica, and Perilla frutescens var. japonica) significantly inhibited NO production and β-hexosaminidase release. Overall, we examined the inhibitory effects of 28 natural product extracts on macrophage and basophil activity, and the findings demonstrated the potential of natural product extracts for treating asthma and macrophage- and basophil-related diseases.
        4,000원
        3.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        물체의 무게감은 감각 측면에서 중요하게 다뤄진 연구 주제로 물체의 무게뿐만 아니라, 크기, 색상, 재질 등의 영 향을 받아 크기-무게, 색상-무게 그리고 재질-무게 왜곡 현상을 갖는 것으로 알려져 있다. 온도는 우리의 일상생활에 매우 중요한 환경적 요소이나, 물체의 온도가 무게감에 어떤 영향을 미치는지에 대해 충분한 연구가 되어 있지 않다. 본 연구는 물체의 온도가 무게감에 미치는 영향을 파악하고자 하였다. 이를 위해 본 연구는 물체의 온도, 무게를 조정하기 용이한 스테인리스 컵을 무게감 측정 물체로 선정하였고, 온도 5 수준(0, 9, 20, 40, 70℃), 무게 2 수준(250, 400g)의 조합으로 10개의 스테인리스 컵을 준비하였다. 무게감 실험에는 건강한 20대 남여 40명이 참여하였고, modulus 방법에 따라 기준 컵 대비 주어진 컵의 무게감을 평가하였다. 실험 데이터의 분석 결과, 온도, 무게 모두 무게감에 유의한 영향을 주는 것으로 나타났다. 온도가 무게감에 주는 영향은 물체의 무게에 따라 다르게 나타났는 데, 적은 컵 무게(250g)로 컵의 무게감이 작은 경우 컵의 온도는 무게감에 영향을 주지 않았다. 반면, 큰 컵 무게 (400g)에서 낮은 온도에서 무게감이 커지는 것으로 나타났다. 이의 결과는 온도의 물체 무게감의 영향이 크기-무게 왜곡에 따라 달라짐을 의미한다.
        4,000원
        5.
        2019.12 구독 인증기관 무료, 개인회원 유료
        Alopecia has emerged as one of the biggest interests in modern society. Many studies have focused on the treatment of alopecia, such as transplantation of hair follicles or inhibition of the androgen pathway. Hair growth is achieved through proper proliferation of the components such as keratinocytes and dermal papilla cells (DPCs), movement, and interaction between the two cells. The present study examined the effect of the hedgehog (Hh) signaling pathway, which is an important and fundamental signal in the cell, on the morphology and the viability of human keratinocytes and DPCs. Upregulation of Hh signaling caused a morphological change and an increase in epithelium-mesenchymal transition-related gene expression but reduced the viability of keratinocytes, while the alteration of Hh signaling did not cause any change in DPCs. The results show the possibility that the regulation of Hh signaling can be applied for the treatment of alopecia.
        4,000원
        6.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hedgehog (Hh) pathway plays a key role in development from invertebrate to vertebrate. It is known to be involved in cell differentiation, polarity, proliferation, including the development of vertebrate limb and the establishment of flies’ body plan. To investigate how the regulation of Hh pathway affects the development of parthenogenetic murine embryos, the parthenogenetically activated murine embryos were treated with either cyclopamine (Cyc), an antagonist of Hh pathway, or purmorphamine, an agonist of Hh pathway. While Cyc did not affect the blastocyst formation and its total cell number, the chemical reduced the hatching rate of embryos and the expression levels of Fn1 mRNA. The results of the present study show the possibility that Cyc may affect the development of embryos at blastocyst stage by blocking Hh pathway and this may cause detrimental effect to the embryos at peri-, and post-implantation stages.
        4,000원
        8.
        2018.11 구독 인증기관·개인회원 무료
        Sonic hedgehog (Shh) signaling pathway plays a key role in the development of various vertebrate embryos and remains important in adults. Although Shh signaling pathway has widely been studied in post-implantation stage embryos, only few studies are reported about pre-implantation stage embryos. To investigate the effect of Shh on pre-implantation stage embryos, cyclopamine and purmorphamine were treated to embryos in culture. Cyclopamine acts as an antagonist of the hedgehog signaling because it has a high affinity to Smoothened, a key part of the hedgehog signaling pathway. On the other hand, purmorphamine activate Smoothened and acts as a Shh signaling agonist. The oocytes were collected after superovulation and parthenogenetically activated in Chatot, Ziomek, and Bavister medium (CZB) including 10 mM strontium for 5 hr. The activated oocytes were cultured in potassium simplex optimized medium (KSOM), KSOM with 5 uM of cyclopamine, KSOM with 1 uM of purmorphamine, or KSOM with both 5 uM of cyclopamine and 1 uM of purmorphamine. After 5.5 days in culture, there was no significant difference in blastocyst development among the four experimental groups. However, the hatching rate was increased in the groups containing purmorphamine, and the blastocysts of the purmorphamine-containing groups had higher total cell number than those of other two groups when the cells were counted after Hoechst33342 staining. Quantitative real-time PCR (qRT-PCR) shows the difference of gene expression level which are related to epithelial-mesenchymal transition (EMT). Taken together, this study suggests that the increase of Shh has an effect on the increases of EMT-related genes and hatching rate of pre-implantation stage embryos, and this may improve implantation subsequently.
        9.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        While designation status of state-appointed cultural properties, promotion status of scenic sites, overlap with natural parks, and relationship with both nine river bends and eight views were reviewed, application and promotion status of scenic sites were analyzed by exploring culture and tourism websites of local governments and tourist leaflets on scenic sites. The results of the analysis are as follows. There are totally 109 designated scenic sites in Korea and these are distributed in 59 local governments, which account for 26.1% of local governments. Accordingly, unequal regional distribution was found to be significant. As a result of the exploration of the status of overlapping between scenic site-designated areas and national, provincial, and county parks, altogether 53 designated scenic sites that account for 48.6%, overlapped with natural parks. Thus, there is a great need for role sharing and cooperation with natural park management entities in terms of experience programs within scenic sites and cultural commentaries. Meanwhile, there is a significant difference among the local governments regarding the efforts in highlighting cultural properties as tourist resources while universal awareness and promotion of scenic sites was found to be very low. Marking scenic sites on leaflets were prone to lag behind those on homepages. The analysis on status of scenic sites revealed that festivals and events were being held in 39.4% of scenic sites and those with longer designation- lapsed years were associated with the prevalence of festivals. Moreover, natural scenic sites located in natural parks were unwilling to be used through local government’s awareness and tourism endeavors compared to historical and cultural scenic sites. Additionally, several wrong descriptions were found on the markings of scenic sites and thus, promotion of scenic site culture and operational management requires urgent improvement.
        4,000원
        10.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 평창군의 대표적 명승고적으로 분류되는 팔석정의 유래와 그 유래의 원천인 팔석(팔석) 그리고 바위글씨의 현황을 파악하는 한편 바위글씨의 주체인 양사언의 자연관 고찰을 전제로 팔석정에 새겨진 바위글씨의 의미해석을 시도 하였다. 이를 토대로 팔석정의 본질과 문화경관적 가치를 구명함으로써 팔석정의 보존 및 복원을 위한 기초자료 제공을 목적으로 시도된 연구결과는 다음과 같다. 팔석에 새겨진 바위글씨는 ‘봉래⋅영주⋅방장’의 삼신산(삼신산)과 ‘낚시풍류(조어)⋅잠풍류(오수)⋅바둑풍류(위기) ⋅ 연꽃 감상(상련)⋅도약(도약 또는 비상)’ 등 5가지의 풍류 의미를 함의하며, 이는 탈속을 통한 선계지향을 추구했던 양사언의 자연관과 휴양 개념을 담는 풍류놀이로 인식된다. 특히 최상부에 위치한 바위글씨 봉래(봉래)는 양사언의 호 (호)이자 ‘팔석정’과 ‘봉래(봉래고정)’의 주인인 자아(자아) 인식의 기표(기표)로 상정된다. 팔석정은 양사언의 기질과 그 의 시에 드러난 탈속(탈속)과 비상(비상) 등 도가적 유선(유선)을 지향하는 풍류놀이를 적재적소에 표기함으로써 탈속의 공간으로 재해석한 풍류터의 의미를 담는다. 또한 ‘석지청련’ 바위글씨가 전해지는 팔석정가든의 전정(전정)은 “이백과 동일시되는 양사언의 돌 연못”이란 의미로 이는 곧 ‘봉래고정’을 뜻하는 것으로 해석된다. 종합적으로 팔석정은 조선조 대표적 문사이자 서예가인 봉래 양사언의 봉래고정 터와 함께 팔석에 새긴 여덟 개의 바위글씨의 의미가 지속적으로 유전된 임천정원(임천정원)으로서의 장소특성이 잘 드러난 평창의 대표적 정원유적이다.
        4,200원
        11.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        「청구남승도」를 대상으로 조선시대 명승유람놀이의 내용 및 특성을 살핀 본 연구의 결과는 다음과 같다. 「청구남승도」에 나타는 명승지의 도별(道別) 분포 결과 전국 팔도 명승을 고르게 안배하고자 했던 흔적이 잘 드러나 있다. 특히 조선시대 5악으로 알려진 삼각산을 비롯하여 금강산, 지리산, 묘향산 그리고 백두산이 모두 포함되고 있으며 천제단이 있는 마나산과 태백산이 포함되어 있는 것을 볼 때 강토에 대한 애착과 역사의식이 강하게 부각되고 있다. 또한 조선의 대표적 승경으로 회자되는 관동팔경 10개소가 모두 집경에 포함되고 있으며 평양, 공주, 부여, 경주, 개성 그리고 한양 등 우리나라의 고도(古都)의 명승지가 비중 있게 표시되고 있는 것으로 보아 명승고적을 모두 망라하고자 했던 의지가 잘 드러나고 있다. 「청구남승도」에 표기된 명승 중 2015년 3월 현재 국가지정문화재 ‘명승’으로 지정된 곳은 총 21개소로 확인되었다. 「청구남승도」에 표기된 명승지의 유형 분석 결과, 자연명승이 58(48.3%), 역사문화명승 62개소(51.7%)의 고른 비율을 보였으며 자연명승은 명산(名山)이 21(17.5%), 못이 7개소(5.8%), 대(대)가 6개소(5.0%), 강이 4개소(3.4%) 등의 순이었으며 역사문화명승은 누정 33개소(27.5%), 사찰 10개소(8.3%), 읍성과 관아 7개소(5.9%) 의 순위를 보였다. 남승도놀이는 전국의 명승을 익히고 팔도의 풍토⋅산물⋅인물 등을 이해할 수 있는 유람놀이로 자연 경승지와 고도(古都) 등 명승고적을 와유(臥遊)하면서 자연 및 문화경승지를 간접적으로 체험할 수 있는 놀이였다. 이 놀이는 한민족의 역사의식을 강조하면서 국토의 지리적 위치와 명승지에 대한 지식과 관심을 높이는 교육적 효과를 발휘했을 것으로 현 명승 활용에 시사점을 제시하고 있다.
        4,500원
        12.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        3D-based BIM(Building Information Modeling) technologies can be utilized effectively as a means of systematic management of facility information for safety assurance and effective maintenance of waterworks facilities. In this study, BIM models of water treatment facilities that can be used as basic data for BIM-based maintenance of waterworks facilities were developed. Information exchange and generality of the developed BIM models were evaluated by conducting interoperability analysis of IFC(Industry Foundation Classes) conversion models. In addition, the application of COBie(Construction Operations Building information exchange) was recommended as an effective countermeasure to deal with technical limitation regarding exchange and utilization of facilities-related information through current IFC models. The results of this study can contribute to the development of BIM-based maintenance system for waterworks facilities.
        4,200원