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      • KCI등재

        해상형 국립공원 탐방수요의 요인분해

        모수원 ( Mo Soo-won ),이광배 ( Lee Kwang-bae ),박정환 ( Park Jeong-hwan ) 한국도서(섬)학회 2018 韓國島嶼硏究 Vol.30 No.2

        국내관광은 국제관광의 변동성이 주는 충격을 완화하려 관광산업의 안정성을 담보하는 역할을 수행함에도 불구하고 국내관광부문은 활성화되지 못하고 있다. 이러한 점은 우리나라의 해외관광객은 2010년-2017년에 연평균 11.3%라는 높은 증가를 보인데 비해 우리나라 국립공원의 탐방객은 연평균 1.5% 성장이라는 초라한 실적을 드러내고 있다는 데서 알 수 있다. 더욱 산악형 국립공원에 대해서는 비교적 많은 연구가 이루어지고 있는데 비해 해상형 국립공원에 대해서는 상대적으로 연구와 관심이 빈약한 편이다. 이에 본고는 변이할당분석과 BCG분석을 이용하여 해상형 국립공원 탐방객의 변동요인을 식별한다. 먼저 변이할당분석을 적용하여 4개 해상형 국립공원 탐방객의 변동을 국립공원 전체에 대한 탐방수요가 개별 국립공원탐방수요에 미치는 국립공원효과, 국립공원 전체에 대한 매력과 해상형 국립공원에 대한 매력의 차이가 개별 국립공원 탐방수요에 미치는 해상형 국립공원효과, 그리고 개별 국립공원과 해상형 국립공원의 탐방수요가 미치는 소위 경쟁력효과와 같은 3개 요인으로 분해한다. 또한 변이할당분석을 정태적 분석과 동태적 분석으로 구분하여 정태적 분석과 동태적 분석의 3개효과가 부호와 크기에서 상당한 차이를 노정한다는 것도 밝힌다. 구체적으로 우리나라 4개 해상형 국립공원의 탐방객 변동을 요인별로 분해하여, 정태적 분석에서는 국가효과와 구성효과가 양의 값으로 4개 해상형 국립공원 탐방객을 증가시키나, 동태적 분석에서는 구성효과의 경우 2013년부터, 국가효과의 경우 2014년부터 음의 부호를 갖는다는 것을 밝힌다. 탐방객이 증가한 오동도, 다도해해상국립공원, 태안해안국립공원은 물론 탐방객이 감소한 변산반도국립공원에서도 개별 국립공원의 경쟁력을 의미하는 지역효과가 가장 큰 영향을 미친다는 것도 보인다. BCG 매트릭스를 적용하여 오동도와 다도해해상국립공원은 star 영역으로 상승한 후star 위상을 유지하며, 변산반도국립공원은 star에서 cash cow와 child로 위상이 변화하여 탐방객 증가가 평균 이상을 유지하고 있는데 비해 태안해안국립공원은 child에서 dog로 추락함을 보인다. 이러한 분석을 통해 4개의 해상형 국립공원 모두에서 지역효과가 탐방객 변동에 가장 큰 영향을 미친다는 것과, 오동도와 다도해해상국립공원의 경쟁력은 우수하나 변산반도 국립공원의 경쟁력은 정체상태에 있으며, 태안해안국립공원의 경쟁력은 하락하고 있음을 밝힌다. BCG분석에서는 오동도와 다도해해상국립공원이 탐방객에서 경쟁력이 있다는 것과 태안해안국립공원에서 가장 큰 경쟁력 향상이 이루어져야 한다는 것도 밝힌다. Tourism is widely considered one of the world's largest and rapidly growing industries. Domestic tourism, however, remains an under-researched theme in many countries involving Korea partly due to the difficulty to track domestic tourism and with governments and policy-makers placing emphasis on the attractive higher expenditures of foreign visitors. It is stated that a vibrant domestic tourism sector can cushion the industry from fluctuations of the international tourism market and bring stability and predictability in the industry. Nature-based tourism to national parks gives us broad benefits such as improved physical and mental health, stress reduction and increased social cohesion. Employment is one of tourism’s main development advantages and its role in promoting economic opportunities for communities adjacent to national parks has long been appreciated. But tourism performance in Korean national parks continues to dwindle and stagger. This paper introduces a shift-share decomposition to break down the tourism to the marine national parks into three components: one measuring national effect, and two other components due to changes in compositional effect and regional effect respectively. While the static shift-share analysis shows that the growth in marine national parks’tourism seems to be due to positive national park effect as well as marine national park effect, the dynamic regional effect appears to have a negative effect on visitors. This paper also employs the positioning analysis on national parks using Boston Consulting Group matrix over the period 2011-2016. The BCG analysis shows that Odongdo and Dadohaehaesang succeed in rising to a star area, Byeonsanbando ranges over a cash cow to a child, but Taeanhaean degrades from a child to a dog area.

      • KCI등재

        C2C12 근육세포에서 과산화수소로 유도된 산화 스트레스에 대한 시체(柿蒂)의 보호효과

        박정환,임진영,이민아,성은정,이준수,Park, Jeong Hwan,Lim, Jinyeong,Lee, Mina,Seong, Eunjeong,Lee, Junsoo 대한한의학방제학회 2021 大韓韓醫學方劑學會誌 Vol.29 No.4

        Objectives : The calyx of Diospyros kaki Thunb. has usually been used to treat obstinate hiccup. This study investigated the protective effects of Diospyros kaki using C2C12 myoblasts of H<sub>2</sub>O<sub>2</sub>-induced oxidative stress. Methods : Cell viability and cytotoxicity were determined by MTT assay. The level of reactive oxygen species (ROS), malondialdehyde (MDA), and reduced glutathione (GSH) were measured by using optical properties. Results : The calyx of Diospyros kaki Thunb. extract showed no toxicity to C2C12 myoblasts until 20 ㎍/mL concentration and increased cell viability compared to the H<sub>2</sub>O<sub>2</sub> treated group. The calyx of Diospyros kaki Thunb. extract inhibited the production of ROS and MDA at all concentrations. In addition, the calyx of Diospyros kaki Thunb. extract increased the concentration of GSH. Conclusion : This study provides that the calyx of Diospyros kaki Thunb. can be used as a potential material that exhibit antioxidative and protective effects on H<sub>2</sub>O<sub>2</sub>-induced oxidative stress in C2C12 Myoblasts.

      • KCI등재

        Realization of Primary Thermometer from Electrical Shot Noise in a Metal-Insulator-Metal Tunnel Junction

        박정환,최정숙,김정구,류상완,송운,정연욱,Park, J.H.,Rehman, M.,Choi, J.S.,Khim, Z.G.,Ryu, S.W.,Song, W.,Chong, Y. The Korean Superconductivity Society 2010 Progress in superconductivity Vol.11 No.2

        We measured electrical shot noise in a metal-insulator-metal tunnel junction, which was made by using electron-beam lithography and double-angle evaporation technique. Since the dependence of the shot noise on bias voltage and temperature is theoretically well known, we can determine the temperature of the junction by measuring the noise as the voltage across the junction is changed. A cryogenic low noise amplifier was used to amplify the noise signal in the frequency range of 600-800 MHz, which enabled fast measurement of noise signal and thus temperature. With further study, this method could be useful for primary thermometry in cryogenic temperatures.

      • KCI등재

        Tat-indoleamine 2,3-dioxygenase 1 elicits neuroprotective effects on ischemic injury

        박정환,Dae Won Kim,Min Jea Shin,Jinseu Park,한규형,이근욱,Jong Kook Park,Yeon Joo Choi,여현지,여은지,Eun Jeong Sohn,Hyoung-Chun Kim,Eun-Joo Shin,Eun-Joo Shin,김덕수,조용준,Won Sik Eum,최수영 생화학분자생물학회 2020 BMB Reports Vol.53 No.11

        It is well known that oxidative stress participates in neuronal cell death caused production of reactive oxygen species (ROS). The increased ROS is a major contributor to the development of ischemic injury. Indoleamine 2,3-dioxygenase 1 (IDO-1) is involved in the kynurenine pathway in tryptophan metabolism and plays a role as an anti-oxidant. However, whether IDO-1 would inhibit hippocampal cell death is poorly known. Therefore, we explored the effects of cell permeable Tat-IDO-1 protein against oxidative stress-induced HT-22 cells and in a cerebral ischemia/reperfusion injury model. Transduced Tat-IDO-1 reduced cell death, ROS production, and DNA fragmentation and inhibited mitogen-activated protein kinases (MAPKs) activation in H2O2 exposed HT-22 cells. In the cerebral ischemia/ reperfusion injury model, Tat-IDO-1 transduced into the brain and passing by means of the blood-brain barrier (BBB) significantly prevented hippocampal neuronal cell death. These results suggest that Tat-IDO-1 may present an alternative strategy to improve from the ischemic injury.

      • SCOPUSKCI등재

        물분해용 Cu<sub>2</sub>O 박막/ZnO 나노막대 산화물 p-n 이종접합 광전극의 광전기화학적 특성

        박정환,김효진,김도진,Park, Junghwan,Kim, Hyojin,Kim, Dojin 한국재료학회 2018 한국재료학회지 Vol.28 No.4

        We report on the fabrication and photoelectrochemical(PEC) properties of a $Cu_2O$ thin film/ZnO nanorod array oxide p-n heterojunction structure with ZnO nanorods embedded in $Cu_2O$ thin film as an efficient photoelectrode for solar-driven water splitting. A vertically oriented n-type ZnO nanorod array was first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method and then a p-type $Cu_2O$ thin film was directly electrodeposited onto the vertically oriented ZnO nanorods array to form an oxide semiconductor heterostructure. The crystalline phases and morphologies of the heterojunction materials were characterized using X-ray diffraction and scanning electron microscopy as well as Raman scattering. The PEC properties of the fabricated $Cu_2O/ZnO$ p-n heterojunction photoelectrode were evaluated by photocurrent conversion efficiency measurements under white light illumination. From the observed PEC current density versus voltage (J-V) behavior, the $Cu_2O/ZnO$ photoelectrode was found to exhibit a negligible dark current and high photocurrent density, e.g., $0.77mA/cm^2$ at 0.5 V vs $Hg/HgCl_2$ in a $1mM\;Na_2SO_4$ electrolyte, revealing an effective operation of the oxide heterostructure. In particular, a significant PEC performance was observed even at an applied bias of 0 V vs $Hg/HgCl_2$, which made the device self-powered. The observed PEC performance was attributed to some synergistic effect of the p-n bilayer heterostructure on the formation of a built-in potential, including the light absorption and separation processes of photoinduced charge carriers.

      • KCI등재

        체감온도이론의 비교 연구

        박정환,한욱,박래설,Park, Jeon-Hwan,Han, Uk,Park, Rae-Seol 한국지구과학회 2002 한국지구과학회지 Vol.23 No.8

        겨울철 체감온도는 온도와 바람에 의해 느끼는 추위의 정도를 정량화한 것이다. Siple-Passel은 최초로 바람에 의한 냉각효과를 이용하여 바람냉각상당온도를 제시하였으나 일반인에게 적합하지 않기 때문에 많은 문제점이 지적되어 왔으므로 이 논문에서 결점들을 비교 분석하였다. Steadman 모델은 열평형(thermal equilibrium) 이론에 근거하여 보다 현실적이지만 추위의 정도를 구분하여 설명하지 못하였다. 최근 캐나다와 미국에서 개발한 JAG/TI-모델은 보다 정확하고 이해하기 쉬우며 인체실험을 반영하였으나 태양복사, 습도, 개인의 신체적 차이 등은 고려하지 않았다. 나이, 사람의 활동, 건강, 신진대사 등이 다르기 때문에 어느 모델이 사람에게 적합한지는 실험 비교가 필요하다. 따라서 우리의 야전환경에 적합한 체감온도모델의 개발이 요구된다. The concept of sensible temperature in winter is an attempt to quantify the sensation of cold by dry-bulb temperature combined with wind speed. Siple-Passel’s windchill equivalent temperature originated in experiments that are not conformable to various human conditions. Therefore, many investigators have found the flaws which are listed. Steadman’s model is based on the concept of thermal equilibrium and more sound and more representative of human conditions. But no classifications exist for Steadman’s windchill equivalent temperature, yet. The JAG/TI-model which was developed by US and Canada is more accurate, easy to understand and reflects human beings by conducting experiments using human volunteers but didn't take into account solar radiation, wet condition and physical state of the individual. Because of individual differences in people’s age, activity, health, metabolic rate, etc., no experimental evidence exists to suggest whether Siple-Passel’s, Steadman’s and JAG/TI-model’s windchill equivalent temperature is more applicable to the majority of people. Therefore we need the windchill model which is best applicable to Korean Army.

      • KCI등재

        P3HT/POSS 합성 활성층을 이용한 OTFT 소자의 대기안정성 향상

        박정환,한교용,Park, Jeong-Hwan,Han, Kyo-Yong 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.2

        In order to improve air stability, we proposed a new active layer of an organic TFT by synthesizing P3HT/POSS conjugated polymer. P3HT/POSS OTFTs with the various P3HT/POSS volume ratios were fabricated and characterized. With the P3HT/POSS volume ratio of 1:1, we achieved the field-effect mobilities of ${\sim}1.19{\times}10^{-3}\;cm^2/v{\cdot}sec$ in the saturation region and the current on/off ratio of ${\sim}2.51{\times}10^2$. The resulting current on-off ratio was much higher than that of the P3HT-based OTFTs and resulted from the dramatic decrease of the off-current. Since the off-current can be reduced by preventing oxygen in atmosphere from doping the P3HT/POSS active layers, this new active layer shows its ability to avoid oxygen doping in atmosphere. Therefore, the improvement of the air stability can be achieved by employing the P3HT/POSS active layers.

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