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        161.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Observations show that the accretion ows in low-luminosity active galactic nuclei (LLAGNs) probably have a two-component structure with an inner hot, optically thin, advection dominated accretion flow (ADAF) and an outer truncated cool, optically thick accretion disk. As shown by Taam et al. (2012), within the framework of the disk evaporation model, the truncation radius as a function of mass accretion rate is strongly affected by including the magnetic field. We define the parameter β as pm = B2=8π = (1 - β)ptot, (where ptot = pgas + pm, pgas is gas pressure and pm is magnetic pressure) to describe the strength of the magnetic field in accretion ows. It is found that an increase of the magnetic field (decreasing the value of β) results in a smaller truncation radius for the accretion disk. We calculate the emergent spectrum of an inner ADAF + an outer truncated accretion disk around a supermassive black hole by considering the effects of the magnetic field on the truncation radius of the accretion disk. By comparing with observations, we found that a weaker magnetic field (corresponding to a bigger value of β) is required to match the observed correlation between L2-10keV/LEdd and the bolometric correction K2-10keV, which is consistent with the physics of the accretion ow with a low mass accretion rate around a black hole.
        3,000원
        162.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although the link between activity in the nuclei of galaxy and galactic mergers has been under scrutiny for several years, it is still unclear to what extent and for which populations of active galaxies merger- triggered activity is relevant. The environments of AGN allow an indirect probe of the past merger history and future merger probability of these systems, suffering less from sensitivity issues when extended to higher redshifts than traditional morphological studies of AGN host galaxies. Here we present results from our investigation of the environment of radio selected sources out to a redshift z=2. We employ the first data release J-band catalog of the new near-IR Infrared Medium-Deep Survey (IMS), 1.4 GHz radio data from the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey and a deep dedicated VLA survey of the VIMOS field, covering a combined total of 20 sq. degrees. At a ux limit of the combined radio catalog of 0.1 mJy, we probe over 8 orders of magnitude of radio luminosity. Using the second closest neighbor density parameters, we test whether active galaxies inhabit denser environments. We find evidence for a sub-population of radio-selected AGN that reside in significantly overdense environments at small scales, although we do not find significant overdensities for the bulk of our sample. We show that radio-AGN in the most underdense environments have vigorous ongoing star formation. We interpret these results in terms of the triggering and fuelling mechanism of radio-AGN.
        3,000원
        163.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recognition of the role of radio galaxies in the universe has been increasing in recent years. Their colossal energy output over huge volumes is now widely believed to play a key role not only in the formation of galaxies and their supermassive black holes, but also in the evolution of clusters of galaxies and, possibly, the cosmic web itself. In this regard, we need to understand the in ation of radio bubbles in the hot gas atmospheres of clusters and the importance of the role that radio galaxies play in the overall energy budget of the intracluster medium. Here, we present results from X-ray and radio band observations of the hot gas atmospheres of powerful, nearby radio galaxies in poor clusters.
        4,000원
        164.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present an analysis of the relation between star-formation (SF) and accretion luminosities of local type-2 active galactic nuclei (AGNs) at 0:01 ≤ z < 0:22. We match type-2 AGNs found in the Sloan Digital Sky Survey to current far-infrared (FIR) survey catalogues based on AKARI and Herschel. Estimating AGN luminosities from [O iii]5007 and [O i]6300 emission lines, we find a positive linear trend between FIR and AGN luminosities over a wide dynamical range. This result appears to be inconsistent with recent reports that low-luminosity AGNs show no correlation between FIR and X-ray luminosities; this contradiction is likely due to Malmquist and sample selection biases. Moreover, we also nd that pure- AGN candidates, for which the FIR radiation is thought to be AGN-dominated, show significant low-SF activities. These AGNs hosted by low-SF galaxies are rare in our sample. However, it is possible that the low fraction of low-SF AGN is caused by observational limitations, as recent FIR surveys are not suffcient to examine the population of high-luminosity AGNs hosted by low-SF galaxies.
        3,000원
        165.
        2015.09 구독 인증기관 무료, 개인회원 유료
        Poria cocos is a well-known traditional Chinese traditional medicine (TCM) that grows around roots of pine trees in China, Korea, Japan, and North America. Poria cocos has been used in Asian countries to treat insomnia as either a single herb or part of an herbal formula. In a previous experiment, pachymic acid (PA), an active constituent of Poria cocos ethanol extract (PCE), increased pentobarbital-induced sleeping behaviors. The aim of this experiment was to evaluate whether or not PCE and PA modulate sleep architectures in rats as well as whether or not their effects are mediated through GABAA-ergic transmission. PCE and PA were orally administered to individual rats 7 days after surgical implantation of a transmitter, and sleep architectures were recorded by Telemetric Cortical encephalogram (EEG) upon oral administration of test drugs. PCE and PA increased total sleep time and non-rapid eye movement (NREM) sleep as well as reduced numbers of sleep/wake cycles recorded by EEG. Furthermore, PCE increased intracellular chloride levels, GAD65/67 protein levels, and α-, β-, and γ-subunits of GABAA receptors in primary cultured hypothalamic neuronal cells. These data suggest that PCE modulates sleep architectures via activation of GABAA-ergic systems. Further, as PA is an active component of PCE, they may have the same pharmacological effects.
        4,000원
        166.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, several kinds of active carbons with high specific surface area and micro pore structure were prepared from the coconut shell charcoal using chemical activation method. The physical property of prepared active carbon was investigated by experimental variables such as activating chemical agents to char coal ratio, flow rate of inert gas and temperature. It was shown that chemical activation with KOH and NaOH was successfully able to make active carbons with high surface area of 1900~2500 m2/g and mean pore size of 1.85~2.32 nm. The coin cell using water-based binder in the electrolyte of LiPF6 dissolved in mixed organic solvents (EC:DMC:EMC=1:1:1 vol%) showed better capacity than that of oil-based binder. Also, it was found that the coin cell of water-based binder shows an improved cycling performance and coulombic efficiency.
        4,000원
        167.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study aims to establish the priority of introducing anti-icing spray system for regions of the National Highways in South Korea. Using this study, a logical plan for instituting such an anti-icing spray system can be established for the National Highways METHODS : The Analytical Hierarchy Process (AHP) was employed to prioritize the implementation of an anti-icing spray system on Korean highways. For this purpose, an existing scoring table developed by the Ministry of Land, Infrastructure Transport Affair was slightly modified in order to reflect recent trends in winter maintenance. A survey was conducted to gather the preferences regarding the developed hierarchy of road experts and agencies. Finally, the final score was produced by integrating the scoring results with estimated weights for each evaluation criterion. RESULTS: In general, Honam and the metropolitan areas have relatively high priority while other areas such as Chungcheong, Young Nam, and Gang Won appear to be uniform in importance in terms of establishing an anti-icing spray system. This result may indicate that historical weather data and traffic volumes are significant factors in deciding in winter maintenance polices CONCLUSIONS : In this study, useful insights are suggested regarding winter maintenance by simultaneously performing rapid snow removal and proactive treatment. Issues of resource allocation may be potential research items in the field transportation engineering.
        4,000원
        168.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Introduction 5 working days a week and wellness trends, that allows more consumers to actively enjoy outdoor activities, has led to a rapid growth in the outdoor clothing market. Buyers of outdoor clothing perceive them as causal and functional clothes that they can wear comfortably in daily life as well as for outdoor activities such as hiking and fishing (Park et al., 2002). There is an increased interest in outdoor activities by seniors who engage in various hobbies for health. Active seniors are energetic retirees who actively enjoy their retirement. They have emerged as a new consumer group in the inactive culture market (such as travel and the performing arts) due to their enjoyment of activities (such as language study, computer education, cosmetic/beauty treatments and sports) that is different from previous generations of older people (Korean Economic glossary, 2014). The most striking characteristic of active seniors is their generous investment in self-development based on secure assets and retirement income. Many studies have been done on senior citizens based on age that have examined body types (Ahn, 2003; Kim, 1995; Lee & Kim, 2007) and original clothing forms (Lee, 2003; Nam & Choi, 2002; Moon, 2008). However, these studies did not fully reflect the needs of active seniors interested in clothing. Additionally, most studies were conducted on female seniors with few studies on male seniors. It is necessary to accept and understand changes in the body types and physical functions of seniors body types and physical functions that accompany age and changing aesthetic sense with styles that are differentiated from existing elderly groups in regards to clothing for active seniors. A study on older men's body classification (Kim & Lee, 2003) indicated that the characteristics of older men's body types were not fully considered because a clothing sizing system was not separately established for older people. Most outdoor clothing companies produced patterns for a young generation. This study was conducted on the outdoor jacket wearing pattern of active male seniors. The results of this study can be used to design outdoor jackets that are produced at a reasonable price with a wearable function useful for outdoor activities and daily life.
        3,000원
        169.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kegel exercise is commonly prescribed to improve the urination and evacuation capabilities of a patient. Assistive devices developed for Kegel exercise are found limited in terms of clinical effectiveness and motivation. The present study is intended to develop a serious game to support active and sustainable Kegel exercise for patients. A four-step process (benchmarking, analysis of patent and technology, ideation of hardware and software, and implementation) is applied in the present study to development of a Kegel serious game. The proposed serious game for active Kegel exercise needs to be validated in urology clinics.
        4,000원
        172.
        2015.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effects of the mixing of an active material and a conductive additive on the electrochemical performance of an electric double layer capacitor (EDLC) electrode were investigated. Coin-type EDLC cells with an organic electrolyte were fabricated using the electrode samples with different ball-milling times for the mixing of an active material and a conductive additive. The ball-milling time had a strong influence on the electrochemical performance of the EDLC electrode. The homogeneous mixing of the active material and the conductive additive by ball-milling was very important to obtain an efficient EDLC electrode. However, an EDLC electrode with an excessive ball-milling time displayed low electrical conductivity due to the characteristic change of a conductive additive, leading to poor electrochemical performance. The mixing of an active material and a conductive additive played a crucial role in determining the electrochemical performance of EDLC electrode. The optimal ball-milling time contributed to a homogeneous mixing of an active material and a conductive additive, leading to good electrochemical performance of the EDLC electrode.
        4,000원
        174.
        2014.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present a GUI-based interactive Python program, VIMAP, which generates radio spectral index maps of active galactic nuclei (AGN) from Very Long Baseline Interferometry (VLBI) maps obtained at different frequencies. VIMAP is a handy tool for the spectral analysis of synchrotron emission from AGN jets, specifically of spectral index distributions, turn-over frequencies, and core-shifts. In general, the required accurate image alignment is difficult to achieve because of a loss of absolute spatial coordinate information during VLBI data reduction (self-calibration) and/or intrinsic variations of source structure as function of frequency. These issues are overcome by VIMAP which in turn is based on the two-dimensional cross-correlation algorithm of Croke & Gabuzda (2008). In this paper, we briefly review the problem of aligning VLBI AGN maps, describe the workflow of VIMAP, and present an analysis of archival VLBI maps of the active nucleus 3C 120.
        4,000원
        177.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 LSCF/GDC (20 : 80 vol%) 복합 분리막 표면에 LSC/GDC (50 : 50 vol%) 활성층을 코팅한 후 활성층의 열처리 온도, 두께, 침투법을 이용한 STF 도입이 산소투과 특성에 미치는 영향을 고찰하였다. 활성층 도입은 복합 분리막의 산소 투과 유속을 급격히 증진시켰으며 이는 활성층 성분인 LSC/GDC (50 : 50 vol%)가 전자 전도성 및 표면 산소 분해 반응을 증진시켰기 때문이었다. 활성층의 열처리 온도가 900˚C에서 1000˚C로 증가한 경우, 산소 투과 유속은 증가하였고 이는 분리막과 활성층 사이 그리고 활성층의 결정입간 접촉이 증진하여 산소이온과 전자 흐름을 증진시켰기 때문으로 설명되었다. 코팅층의 두께가 약 10μm에서 약 20μm로 증가한 경우, 산소 투과 유속은 오히려 감소하였는데 이는 코팅층의 두께가 증가할수록 기공을 통한 공기 중의 산소 유입이 어려워지기 때문으로 설명되었다. 또한, 코팅층에 침투법을 이용하여 STF를 도입한 경우가 STF를 도입하지 않은 경우 보다 높은 산소 투과 유속을 보였는데 이는 도입된 STF가 산소 분해하는 표면 반응 속도를 촉진시키기 때문이다. 본 연구로부터 LSC/GDC (50 : 50 vol%) 활성층 코팅 및 특성 제어는 LSCF/GDC (20 : 80 vol%) 복합 분리막의 산소투과 증진에 매우 중요함을 확인하였다.
        4,000원
        178.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 P. aeruginosa와 E. hirae을 대상으로 orthophenylphenol 20%를 함유한 훈증소독제, Fumagari OPP®의 살균효과를 평가하기 위해 수행되었다. 예비 시험에서, P. aeruginosa와 E. hirae의 현탁액 균수는 각각 2.8 × 108 와 3.6 × 108CFU/mL이었으며, 모든 훈증소독제에 노출시킨 담체의 균수는 모두 평판배지법과 여과법으로 배양한 시험균주 현탁액의 균수의 50%보다 많았다. 또한, 대조 담체로부터 회복된 P. aeruginosa와 E. hirae 균수는 각각 2.9 × 106와 2.7 × 106CFU/mL이었다. 훈증소독제의 살균효과 시험에서는, 훈증소독제를 처리한 담체의 P. aeruginosa 와 E. hirae의 감소 균수는 각각 6.46와 5.19 logCFU/mL 로 나타났다. 이상의 결과로부터, 훈증소독제, Fumagari OPP®는 P. aeruginosa와 E. hirae에 대해 효과적인 살균력 을 갖는 것으로 확인되었으며, 병원성 세균에 오염된 식품재료 및 주방용품의 소독에 적용할 수 있을 것으로 사료된다.
        4,000원
        179.
        2014.07 구독 인증기관·개인회원 무료
        In services in general, customers play critical roles in determining the success of service delivery. Some services (such as education) require an active participation of customers for the successful accomplishment of purchase objectives. Yet, there are few systematic and integrated researches in defining the dimensions of customer’s active participation and in empirically testing the effect of customer’s active participation on customer’s perceived performance (as opposed to the firm’ performance and customer satisfaction). Existing studies have focused mainly on the general concept of customer participation during a service encounter, leaving the specific concept of customer’s active participation in various situations still under-researched. Through this study, we intended to fill this gap in research. Specifically, using college business education as our study context, we first propose the concept of “customer’s active participation (CAP)” as the reflection of customer engagement concept and identify the dimensions of CAP. We then empirically examine the effect of CAP on customer perceptions of performance of their own (CPP). Through the review of literature on the topics of customer participation, customer engagement, employee engagement and focus group interviews, we defined customer’s active participation and identified its dimension as follows. We defined customer’s active participation as “customers' making not only their individual efforts to ensure the successful outcome of the service delivery but also active interacting with service providers, other customers, and others in and outside of the service delivery context to achieve their consumption goal”. We then identified five dimensions of customer’s active participation; in-service-space interaction, 3 kinds of outside-service-space interactions (customer-to-service provider, customer-to-customer, customer-to-others), and individual level participation both in and outside the service space. In order to collect necessary data, we administered a self-administered survey using a questionnaire among undergraduate-level business major students at Yonsei School of Business. As a result of an EFA, we confirmed the uni-dimensionality of each of five determinants and the reliability of the measurement items for each dimension. The CFA result of a different set of data collected from another set of respondents among undergraduate business major students at Yonsei School of Business, we confirmed that the five dimensions well explain the customer’s active participation (CAP). Results also supported that customer’s active participation (CAP) positively influences customer’s perceptions of performance (CPP). This study contributes academically and practically in several ways. First, this study is the first attempt to propose the concept of “customer’s active participation (CAP)”. Second, this study identified the major determinants of CAP and developed a scale in the business education context. Third, this study empirically verified and the importance of the effect of CAP on their perception of own performance. Practically, this study contributes by showing the importance of managing CAP and by proposing the specific dimensions of CAP that should be managed.
        180.
        2014.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We apply differential affine velocity estimator (DAVE) to the Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI) 12-min line-of-sight magnetograms, and separately cal- culate the injected magnetic helicity for the leading and the following polarities of nine emerging bipolar active regions (ARs). Comparing magnetic helicity ux of the leading polarity with the following polarity, we nd that six ARs studied in this paper have the following polarity that injected more magnetic helicity ux than that of the leading polarity. We also measure the mean area of each polarity in all the nine ARs, and nd that the compact polarity tend to possess more magnetic helicity ux than the fragmented one. Our results con rm the previous studies on asymmetry of magnetic helicity that emerging bipolar ARs have a polarity preference in injecting magnetic helicity. Based on the changes of unsigned magnetic ux, we divide the emergence process into two evolutionary stages: (1) an increasing stage before the peak ux and (2) a constant or decreasing stage after the peak ux. Obvious changes on magnetic helicity ux can be seen during transition from one stage to another. Seven ARs have one or both polarity that changed the sign of magnetic helicity ux. Additionally, the prevailing polarity of the two ARs, which injects more magnetic helicity, changes form the following polarity to the leading one.
        4,000원