• The Korean Journal of Mycology
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• v.15 no.3
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• pp.135-141
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• 1987

Interspecific heterokaryons were obtained by polyethylene glycol induced fusion of protoplasts from auxotrophic mutants of P. ostreatus+P. cornucopiae, P. ostreatus+P. florida, P. ostreatus+P. sajor-caju, P. florida+P. cornucopiae, P. florida+P. sajor-caju and P. sajor-caju+P. cornucopiae protoplasts. The Fusion products of protoplasts were induced by MCM+benomyl, but segregation of sectors were not identified. Interspecific fusion products of protoplasts between incompatible strains did not form true clamp connections and did not produce fruit bodies. For induction of fertility, interspecific heterokaryons crossed with their parents by hyphal anastomosis.

• Applied Microscopy
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• v.27 no.3
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• pp.295-308
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• 1997

Liver tissues were taken from rats 20 min after administration of dehydrocholic acid and biligrafin, fasted for 8 days, and bile duct ligation for 48 hr. And the zonulae occludentes around the bile canaliculi were investigated by the freeze fracture method. In the normal rats, the zonulae occludentes showed networks consisting of one to four strands in many regions. After administration of dehydrocholic acid, the depth of zonulae occludentes were increased and networks consist of six to nine strands. The zonulae occludentes, however, were disorganized, and strands were reduced after administration of biligrafin. In the fasting rats, the zonulae occludentes showed one or two strands which were loosely linked. After ligation of bile duct, the zonulae occludentes were disorganized, and strands were reduced or still in a state not to be reduced. The strands were interrupted by gaps or linear particles in all the groups, especially in the biligrafin and the ligation. The free ends were remarkable in the fasting group and contact or surround the lateral gap junctions in the dehydrocholic acid group. The discontinuities and free ends of strands were also encountered in the normal group, thus suggesting that the barrier is not complete even in the normal state. The aggregation of particles appeared within the meshwork of zonulae occludentes in all the group, except for the ligation. From the evidence, it is assumed that zonulae occludentes are labile, differ in the structure according to the situation of bile canaliculi and show regional alterations even in the same bile canaliculi, that zonulae occludentes are affected by mechanical stress or certain other factors, and that there is a correlation between the strands and particle aggregations in association with the alteration of zonulae occludentes.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.286-294
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• 2017

Development of transportation is rapidly reducing the barriers between countries, but this is causing the easier migration of species than the past. Typically, exotic species are imported for the purpose of food, leather, and pets. However, it has been introduced into the wild through artificially or naturally paths, and recently they are become a main cause of ecosystem disturbance. In this study, we investigated exotic turtle species introduced into the wild and analyzed their distribution characteristics. As a result of filed surveys, totally 4 genus 8 species 62 individuals of exotic turtles were found from 126 reservoirs in Gangwon-do and Gyeongsangnam-do, South Korea. In particular, Trachemys scripta elegans showed relatively high frequency than other turtle species and the natural reproduction of T. s. elegans was confirmed in some areas. On the other hand, the frequency of discovery of exotic turtles except T. s. elegans was relatively low, and the range of the areas was limited. Especially, exotic turtles except T. s. elegans were mainly found in public places such as reservoirs in the park. As a result of analyzing the distribution characteristics of exotic turtles using geographic information system, the turtles' distribution showed a high correlation with the artificial factor such as "urban". In this study, we identified the distribution characteristics of exotic turtles in the Korean wild, and these results will be important data for understanding status the and establishing effective management methods for exotic species.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.74-84
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• 2016

Open Source Software (OSS) is a new paradigm for software development. The system is based on the notion of giving software (including sources) away for free, and making money on services, customizing and maintenance. For these reasons, many software companies have considered adopting and using OSS in Software R&D. A variety of factors may influence the use of decision making of OSS. The objective of this study was to explore the significant factors affecting the use decision of OSS and the job performance of OSS usage in software R&D. A research model was suggested based on the TOE Framework and Information Systems Success Model. These findings show that technical benefits of OSS have significant effects on OSS use. The technical benefits of OSS, and organization context, in turn, have significant effects on the use of OSS. On the other hand, the technical risks of OSS and the environment context have no effects on OSS use. In addition, OSS use and user satisfaction have significant effects on the individual job performance. This research contributes towards advancing the theoretical understanding of the OSS Benefits and Performance in Software Development.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.116-116
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• 2018

부식은 재료와 사용 환경과의 상호작용에 의한 결과로서 일반적으로 두께의 감소와 균열의 발생 및 파손 등의 문제로 나타난다. 특히 사용환경 중에서 해수 분위기는 금속의 부식에 가장 유리한 조건이다. 따라서 해양환경 중 항만이나 조선 및 해양 산업 등에 많이 이용되는 강 구조물은 이에 대응하기 위하여 도장방식이나 음극방식을 사용하고 있다. 여기서 음극방식은 피방식체를 일정전위로 음극 분극하는 원리로써 외부전원을 인가하거나 비전위의 금속을 전기적으로 연결하여 방식하는 방법이다[1]. 한편, 해수 중에서 이와 같은 원리로 음극방식 할 경우에는 피방식체인 강재표면에 부분적으로 칼슘 또는 마그네슘 화합물 등의 생성물이 부착하는 현상을 볼 수 있게 된다. 이와 같이 수산화마그네슘($Mg(OH)_2$)및 탄산칼슘($CaCO_3$)을 주성분으로 하여 석출되는 석회질 피막(calcareous deposits)은 피방식체에 유입되는 음극방식 전류밀도를 감소시켜 주거나 물리적 장벽의 역할을 함으로써 외부의 산소와 물 등 부식환경으로부터 소지금속을 보호한다[2]. 그러나 석회질 피막은 소지금속과의 결합력, 막의 균일한 분포, 내식성 및 제작시간의 단축 등 해결해야 할 과제가 있다. 또한 여러 가지 환경 조건 등의 영향을 받아 그 피막의 형성 정도도 가늠하기 어렵기 때문에 음극방식 설계 시 그 정도에 따른 영향을 고려-반영하기가 곤란하다. 따라서 본 연구에서는 석출속도, 밀착성 및 내식특성을 향상시키기 위해 전착프로세스를 통해 해수 중 기체를 용해시켜 석회질 피막을 제작하고 막의 결정구조 제어 및 특성을 분석-평가하였다. 본 연구에 사용된 강 기판(Steel Substrate)은 일반구조용강(KS D 3503, SS400)을 사용하였으며, 외부전원은 정류기(Rectifier, xantrex, XDL 35-5T)를 사용하여 3 및 $5A/m^2$의 조건으로 인가하였다. 양극의 경우에는 해수에 녹아있는 이온 이외에 다른 성분들이 환원되는 것을 방지하기 위해 불용성 양극인 탄소봉(Carbon Rod)을 사용하였다. 이때 석출속도, 밀착성 및 내식특성 향상을 위해 해수에 주입한 기체의 양은 0.5 NL/min였으며, 기판 근처에 고정하여 음극 부근에서의 반응을 유도하였다. 각 조건별로 제작된 막의 표면 모폴로지, 조성원소 및 결정구조 분석을 실시하였으며, 석회질 피막의 밀착성과 내식특성을 평가하기 위해 규격에 따른 테이핑 테스트(Taping Test, ISO 2409)와 3 % NaCl 용액에서 전기화학적 양극 분극 시험을 진행하여 제작된 막의 내구성과 내식성을 분석-평가하였다. 시간에 따른 전착막의 외관관찰 결과 전류밀도의 증가와 함께 상대적으로 많은 피막이 형성되었고, 용해시킨 기체에 의해 더 치밀하고 두터운 피막이 형성됨을 확인할 수 있었다. 성분 및 결정구조 분석 결과 $Mg(OH)_2$ 성분의 Brucite 및 $CaCO_3$ 성분의 Calcite 및 Aragonite 구조를 확인하였으며, 용해시킨 기체의 영향으로 $CaCO_3$ 성분의 Aragonite 구조가 상대적으로 많이 검출되었다. 밀착성 및 내식성 평가를 실시한 결과 해수 중 용해시킨 기체에 의해 제작한 시편의 경우 견고하고 화학적 친화력이 높은 Aragonite 결정이 표면을 치밀하게 덮어 전해질로부터 산소와 물의 침입을 차단하는 역할을 하여 기체를 용해시키지 않은 3 및 $5A/m^2$ 보다 비교적 우수한 밀착성 및 내식 특성을 보이는 것으로 사료된다.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.81-89
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• 2014

Owing to recent advanced techniques in information and communication technology(ICT), our daily life has been changing very quickly and our life style has also been affected greatly. In the current knowledge and information society, the disabled can have a right to enjoy benefits of advanced ICT technologies. However, there is a barrier called digital divide so that the disabled have some difficulties to communicate to the world with ICT technologies. In this sense, our job is to close digital divide and let the disabled enjoy benefits of ICT technologies. Recently there have been some research works to close digital divide between the disabled and the non-disabled. Among various attempts to close digital divide, improving web accessibility for the disabled is the biggest concern since web is a still representative tool among ICT tools. The purpose of this paper is to propose some practical guidelines for improving web accessibility for the disabled. The proposed improvement guidelines are developed based on the existing web accessibility guidelines and are upgraded for more adaptable to the disabled. Our principles are based on the following philosophy. First, any input transmission must be more confirmed. Second, prevent any instant request. Third, allow the disabled to record or store the contents if necessary. Fourth, reduce physical movement for the disabled. Fifth, provide more interaction tools for the disabled.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.397-409
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• 2015

The Global Financial Crisis and introduction of International Financial Reporting Standards (IFRS) urged the banks to strengthen their asset qualities. The banks dispose their non performing loans(NPLs) consistently to maintain a sufficient BIS capital adequacy ratio. Accordingly, the interests in auctions, as a disposal method, of real estates that secured for NPLs are on the increasing. This study suggest an alternative for fairness consolidation of real estate auctions which secured for NPLs. First, the impartial entry barriers for NPL sales markets need to be eliminated for fair bidding competition in auctions for real estate that secured for NPLs. In addition, the portion of NPL disposal by real estate auctions need to be expanded. Second, the asymmetry of trade information in the retail markets of NPLs and the abuse of offset by NPL owners' also should be restricted. The Fairness improvement of NPL trading process and real estate auction process that secured for them would of great use in the protection of bidders. Futhermore, it would also contribute to the revitalization of real estate auction markets and the resolution of NPLs of banks through fair disposal of distressed assets.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.524-533
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• 2015

This study aims to prove the value of SNS tourism information by confirming the relation between SNS tourism information and perceived risk and by verifying its influence on the intention to switch tourism destination. The data was collected from 302 tourists. For data analysis, SPSS 18.0 program and AMOS 18.0 were conducted. First, functional characteristics of SNS tourism information have been verified to have no relationship with the tourist's perception of risk, and therefore the functional tourism information is thought to cause individual motive regardless of tourist's perception of risk. Second, aesthetic value and economic benefits of SNS tourism information have been analyzed to reduce perceived risk of tourists. Third, a symbol of SNS Tourism information has proved to be an element that increases the risk perceived by tourists, indicating that various kinds of tourism information provided by other channels including SNS can serve as a momentum to make tourists recognize new risks the other way round as new tourism information is accumulated, which acts as new motivating factor.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.17-24
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• 2011

The aim of this study was to assess the outcome of MTA apexification in young permanent anterior teeth. Among the patients with the traumatized permanent incisors which were treated with MTA apexification, the dental records and radiographs were examined only for the patient who had follow-up examination at least 3 months after the treatment. Forty nine patients with 64 teeth were included in this study. Demographic information, location and type of teeth and periodontal injury, pre-treatment periapical lesion, clinical symptoms, status of MTA filling, healing of apical lesion and apical barrier formation after treatment were investigated. The outcome based on clinical and radiographic criteria were assessed. The results were as follows 1. Of 64 immature permanent incisors with MTA apexification, the clinical and radiographic success rates were 89.1% and 73.4%, respectively. 2. The maxillary incisors showed significantly higher success rates than the mandibular incisors. 3. There was no statistically significant difference in success rates among the teeth with different types of teeth and periodontal injury. 4. The status of MTA filling did not influence the clinical and radiographic success.

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.428-432
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• 1998

We fabricated 1$\times$8 array of GaAs/AlGaAs quantum well infrared photodetectors for the long wavelength infrared detection which is based on the bound-continuum intersubband transition, and characterized its electrical and optical properties. The device was grown on SI-GaAs(100) by the molecular beam epitaxy and consisted of 25 period of 40 ${\AA} $ GaAs well and 500 ${\AA} $ $Al_{0.28} Ga_{0.72}$ As barrier. To reduce the possibility of interface states only the center 20 ${\AA} $ of the well was doped with Si ($N_D=2{\times}10^{18} cm^{-3}$). We etched the sample to make square mesas of 200$\times$200 $\mu\textrm{m}^2$ and made an ohmic contact on each pixel with Au/Ge. Current-voltage characteristics and photoresponse spectrum of each detector reveal that the array was highly uniform and stable. The spectral responsivity and the detectivity $D^＊$ were measured to be 180,260 V/W and $4.9{\times}10^9cm\sqrt{Hz}/W$ respectively at the peak wavelength of $\lambda$ =7.8 $\mu\textrm{m}$ and at T=10 K.