• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1738-1748
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• 2019

Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.

• 한국안전학회지
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• 제37권1호
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• pp.1-11
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• 2022

This numerical study investigates the effects of the size of the natural smoke vent area (10% and 1% of the floor area) and the location of the fire source (i.e., at the side and center of the stage) on the temperature distribution in the compartment and velocity distribution and mass flow rate of flow through a natural smoke vent for a reduced-scale model of a theater stage. Then, the mass flow rate of outflow through the natural smoke vent in the event of a fire for a real-scale theater stage was examined. The case with the larger natural smoke vent area and central fire source location showed lower temperature distributions and higher mass flow rates of outflow and inflow than the case with the smaller natural smoke vent area and side fire source location. The trends of the temperature distributions were closely related to those of the mass flow rates for the outflow and inflow. Additionally, the case with the larger natural smoke vent area and central fire source location exhibited the most non-uniform flow velocity distribution in all cases tested. A bidirectional flow, in which the outflow and inflow occur simultaneously, was observed through the natural smoke vent. In the event of a fire situation in a real-scale theater stage, it was predicted that the case with the larger natural smoke vent area and central fire source location would have a mass flow rate of outflow that is 43.53 times higher than that of the case with the smaller natural smoke vent area and side fire source location. The present results indicate that the natural smoke vent location should be determined by considering the location in a theater stage where a fire can occur.

• Natural Product Sciences
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• 제28권1호
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• pp.6-12
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• 2022

Five sesquiterpenoids, 7-epi-eudesm-4(15)-ene,1β,6α-diol (1), 7-epi-eudesm-4(15)-ene,1β,6α-diol (2), saniculamoid D (3), aphanamol I (4), and 4β,10α-dihydroxyaromadendrane (5), were isolated from the stem bark of Aglaia grandis. The compounds' (1-5) chemical structures were identified by spectroscopic data including, IR, NMR (¹H, ¹³C, DEPT 135°, HMQC, HMBC, ¹H-¹H COSY), and HRTOFMS, as well as by comparing with the previously reported spectral data. Therefore, this study described the structural elucidation of compounds 1-5 and evaluated their cytotoxic effects against Hela cervical and B16F10 melanoma cells for the first time, but no significant result was discovered.

• 한국조경학회지
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• 제35권2호통권121호
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• pp.71-80
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• 2007

Korea began preserving and managing natural monuments in 1933 under Japanese Colonization, but North Korea and South Korea were forced to establish separate natural monument management policies because of the division after the Korean Independence. The purpose of this study is to compare and analyze the natural monument management policies of both south and North Korea between 1933 and 2005 to introduce new policies for Korea unification. The following are the results: First, South Korea manages every type of cultural asset, including natural monuments, through the 'Cultural Heritage Protection Act,' whereas North Korea managing its cultural assets through the 'Cultural Relics Protection Act' and the 'Landmark/Natural Monument Protection Act.' Second, South Korea preserves and utilizes natural monuments for the purpose of promoting the cultural experience of Korean people and contributing to the development of world culture, whereas North Korea uses its natural monuments to promote the superiority of socialism and protect its ruling power. Third, North and South Korea have similar classification systems for animals, plants, and geology, but North Korea classifies geography as one of its natural monuments. Unlike South Korea, North Korea also designates imported animals and plants not only for the preservation and research of genetic resources, but also for their value as economic resources. Fourth, North Korea authorizes the Cabinet to designate and cancel natural monuments, whereas South Korea designates and cancels natural monuments by the Cultural Heritage Administration through the deliberation of a Cultural Heritage Committee. Both Koreas' central administrations establish policies and their local governments carry them out, while their management systems are quite different. In conclusion, it is important to establish specified laws for the conservation of natural heritages and clarified standards of designation in order to improve the preservation and management system and to sustain the diversity of natural preservation. Moreover it is also necessary to discover resources in various fields, designate protection zones, and preserve imported trees. By doing so, we shall improve South Korea's natural monument management policies and ultimately enhance national homogeneity in preparation for the reunification of the Koreas in the future.

• 자원ㆍ환경경제연구
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• 제18권4호
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• pp.787-813
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• 2009

최근 기후변화가 가장 큰 이슈로 부각되고 있는 가운데 북극의 해빙이 점차 줄어들고 있다는 점을 강조하고 있다. 이에 따라 세계적으로 화석연료를 줄이려는 정책적 움직임을 보이고 있다. 그런데 기후변화로 인한 북극의 해빙 감소를 천연가스 자원개발 측면에서 보면 예전에 비해 오히려 낮은 단위 비용으로 천연가스를 생산할 수 있는 기회를 만들어주고 있는 것이다. 본 논문은 이러한 양자 모순관계에서 북극의 천연가스에 대한 영유권을 갖고 있는 국가들은 어떠한 정책을 갖고 움직이고 있는지를 살펴보고자 하였다. 특히 북극에서 가장 많은 매장량을 갖고 있는 러시아의 북극에서의 천연가스 개발 정책이 향후 세계 천연가스시장에서의 수급에 미칠 영향이 상당할 것으로 분석되는 바, 이에 대한 국가적 대응책이 마련되어져야 할 것이다. 러시아가 2030~2040년대에 매장량이 풍부한 야말 반도에서 생산된 천연가스를 북극항로를 통해 액화천연가스(LNG) 수송선으로 수출하게 되면 세계 천연가스시장의 구조는 새로운 단계로 발전될 것이다. 왜냐하면 이러한 거래 형태는 이전의 천연가스 거래에 있어서 지리적 한계를 뛰어 넘을 뿐만 아니라 이제까지의 파이프라인 가스(PNG) 거래 중심에서 액화천연가스(LNG) 거래 중심으로 무게가 이동하기 때문이다. 한편 우리나라와 같이 북극에 대한 영유권을 갖고 있지 않은 중국이나 일본의 움직임을 살펴보면서 우리에게 주는 타산지석의 교훈을 얻고자 하는 것이다.

• 헤리티지:역사와 과학
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• 제46권3호
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• pp.78-93
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• 2013

본 연구는 자연유산의 미래의 수요자인 대학생들을 대상으로 천연기념물, 명승으로 대별되는 자연유산과 국 도립공원, 생태 경관보전지역과 같은 유사 개념을 얼마만큼 올바르게 인식하고 있는지를 알아보고, 보존 중요성 등 태도차원에서 각 개념 간의 경쟁구조를 분석하고자 하였다. 연구 결과, 보존의 중요도는 '천연기념물>생태 경관보전지역>국 도립공원>명승'의 순으로 나타나 천연기념물보다는 명승을 상대적으로 덜 보존적으로 인식하고 있다는 것을 알 수 있었다. 또한 순천만, 설악산, 창녕 우포늪, 홍도, 독도, 문경새재, 한라산, 성산일출봉, 영월 고씨굴, 태안 신두리 해안사구 포함 관광명소 10개소를 대상으로 자연유산 유형을 올바르게 인식하고 있는지를 대응분석한 결과, 전반적으로 응답자들은 자연유산에 대한 개념을 바르게 인식하고 있지 않다는 것을 파악할 수 있었으며, 이러한 문제점을 해결할 수 있도록 인식제고 프로그램 마련이 필요하다. 다차원 척도법을 활용하여 자연유산 유사개념 경쟁구조(유사성)를 파악한 결과, 포지셔닝 맵에서 천연기념물과 명승이 비교적 멀리 떨어져 나타난 것을 볼 때 각기 차별화되는 방문자 관리가 요구된다. 포지셔닝 맵 상에 나타난 자연유산 유사개념 경쟁구조와 각 개념에 대한 태도를 구성하는 속성결합의 결과를 살펴보면, 자연유산을 비롯한 네 개념 모두가 뚜렷한 차이를 보이지 않은 것으로 보아 향후 차별화된 홍보전략이 필요하다. 응답자들도 자연유산을 활용보다는 보존의 대상으로 생각하는 경향이 있는 것으로 파악되며, 다양한 관리주체 때문에 천차만별인 관리 수준을 체계화할 필요가 있다고 여겨진다.

• 한국식품조리과학회지
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• 제32권5호
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• pp.637-647
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• 2016

Purpose: This research was to understand the consumer awareness and consumption of natural carbonated drinks in Korea. Methods: A survey was conducted enrolling adults over the age of 20, residing in Seoul and its metropolitan area, and who consumed natural carbonated drinks. Data analysis of 544 valid samples was performed using SPSS 17.0. Results: The study showed that consumers mostly purchased natural carbonated water the most, primarily as a water substitute. However, many other usages that the consumer selected showed a possibility for a more versatile usages of natural carbonated drinks. As for the reason of purchase, 'interest in a new product' showed the highest mean value. The factor 'interest in a new product', 'interest in its effectiveness on skin care and diet', 'lower-calorie products', 'health benefits from the usage of natural flavoring and coloring' and 'recommendation from acquaintances' showed statistically significant higher values for women than men. The most frequent and preferred location for purchase were large discount stores, and the most preferred, major informants were in the order 'tasting events at marts and department stores', 'TV/radio advertisement' and 'recommendations from family/friends'. Analysis of the purchase intent showed high interest for non-alcoholic natural carbonated drinks. Conclusion: The study results can be used as baseline data to establish marketing strategies in the emerging natural carbonated beverage market.

• 대한치과의사협회지
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• 제50권9호
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• pp.544-551
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• 2012

Dental caries is a biofilm-related oral disease, and continues to afflict the majority of the world's population. Although fluoride, delivered in various modalities, remains the mainstay for the prevention of caries, additional approaches are required to enhance its effectiveness. Natural products have been used as a major source of innovative and effective therapeutic agents throughout human history, and have shown promise as a source of components for the development of new drugs. In addition. studies using natural products to prevent or treat oral diseases such as dental caries have received a great deal of attention. A number of compounds, such as epicatechin, allicin and sanguinarine, isolated from natural products, have also been investigated for their efficacy against oral microbial pathogens. However, the use of natural products as an anti-caries agent in clinical practice was controversial because of inadequate knowledge concerning their mechanisms of action and chemical characterization. This study focuses on the current knowledge of natural products in dental caries prevention and suggests natural products are importance sources for the prevention of dental caries.

• 생약학회지
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• 제42권4호
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• pp.329-335
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• 2011

Antimicrobial studies on reproductive organs have been scarcely reported. Candida albicans and Neisseria gonorrhoea test to find out the natural substances of various concentrations in the antimicrobial experiments have been made. Antimicrobial effect of biopole as the natural compound biosynthesis matter that contain anti-inflammatory material, catechin polyphenols and lactic acid as a single natural substance on C. albicans were of great significance. Also the results of antimicrobial effects of biopole, catechin and lactic acid as a single natural substance on N. gonorrhoea, respectively, showed lower concentration than those of the antimicrobial effects on C. albicans. Through the survival of Lactobacillus acidofillus that acts for the protection of the genital tissue the importance of lactic acid was confirmed. Lactobacillus acidofillus protection and C. albicans firmly into disinfected to low concentrations of the natural mixture from biopole and catechin with lactic acid were found and the antimicrobial effects of this natural mixture on N. gonorrhoea were perfect. C. albicans and N. gonorrhoea to disinfect the optimal natural mixture from 2% concentration biopole, 0.2% concentration of catechin and 2% lactic acid were obtained. Through the survival of Lactobacillus acidofillus in the reproductive organs protectable effects were acquired to prevent the infections of reproductive tissue and the recurrence.

• 대한예방한의학회지
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• 제17권2호
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• pp.179-187
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• 2013

Objectives : In many cases, patient's symptoms have been recorded on EMR in natural language instead of medical terminologies. It is possible to build a database by analyzing the symptoms of Korean Medicine(KM) that indicates patient's symptoms in natural language. Using the database, when doctors record patient's symptoms on EMR in natural language, conversely it'll be also possible to extract the symptoms of KM from those natural language. The database will enhance the value of EMR as a medical data. Methods : In this study, we aimed to make data structure of the terminologies that represent the symptoms of KM. The data structure is combinations of smallest unit in natural language. We made the database by analyzing morpheme of the natural language to express the symptoms of KM. Results & Conclusions : By classifying the natural language in 15 features, we made the structure of concept and the data available for morphological analysis.