• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.213-218
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• 2017

The purpose of this study was to develop age-biomass model in Chungnam region containing random effect. To develop the biomass model by species and tree component, data for Pinus densiflora in central region is collected to 30 plots (150 trees). The mixed model were used to fixed effect in the age-biomass relation for Pinus densiflora, with random effect representing correlation of survey area were obtained. To verify the evaluation of the model for random effect, the akaike information criterion (abbreviated as, AIC) was used to calculate the variance-covariance matrix, and residual of repeated data. The estimated variance-covariance matrix, and residual were -1.0022, 0.6240, respectively. The model with random effect (AIC=377.2) has low AIC value, comparison with other study relating to random effects. It is for this reason that random effect associated with categorical data were used in the data fitting process, the model can be calibrated to fit the Chungnam region by obtaining measurements. Therefore, the results of this study could be useful method for developing biomass model using random effects by region.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.529-534
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• 2016

The paper suggests risk management methodology for alleviating casuality accidents at urban railway stations. Risk management deals with countermeasures for reducing accident probability or consequences to reach at the certain level of risk. First of all, Economic evaluations using cost and benefit for all the alternatives are performed. The alternatives exceeding B/C ratio greater than 1, each alternative is applied in the order of higher B/C ratio. this process is repeated when the level of risk is reduced as low as reasonably practical (ALARP). In order to determine the level of ALARP, Level of Service (LOS) for casuality risk at urban railway stations is proposed. The ALARP level is set to the LOS "C". Finally, a case study is applied to the Jongno 3-ga station, which is a highest risky station among all the stations operated by Seoul Metro and Seoul Metropolitan Rapid Transit Cooperation (SMRT).

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.488-497
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• 2016

Given the potential of mobile applications to create new learning opportunities beyond the prevalent use of digital textbooks and Internet lectures, this study aims to derive types and themes of mobile application content that can be effectively integrated with the school curricula. Twenty primary school teachers participated in this study that examines teachers' perceptions about the advantages and disadvantages of printed and digital textbooks' modality, the advantages and disadvantages of mobile learning, and the themes relevant to develop mobile applications. Findings indicate that it is necessary to develop activity-centered applications for vertical use rather than theme-centered applications for horizontal use. In addition, while most ideas derived from teachers center on multimedia access, there was lack of ideas that leverage the affordances of mobile devices for collaborative interaction and location-awareness. Lastly, to promote the diffusion of mobile learning in school environments, this study suggests the need to overcome teachers' epistemology that perceives mobilization against inquiry activities.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.2
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• pp.147-156
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• 2010

This research studied the Perception on the Career Development of the National Technical Qualification(NTQ) Acquisitors. The qualification acquisitors are engaging to the occupation which related to their qualification and willing to even in future. Also, the higher the acquired qualification grade is, the more they prefer their occupation related with. The qualification acquisitiors feel it necessary to develop his career, but only part of them(45.5%) are being supported by the career development system in now; they have only job training as the career development service. The qualification acquisitors are sensitive to a technical changes. In order to compete against these changes, they want to connect with specialist group and to new techniques or knowledges, and to be trained to achieve higher grade qualification. The qualification acquisitors answered that it is responsible for HRDKorea to serve as developing and managing their career. Finally, the agency producing qualification acquisitors, HRDKorea should build the system that can manage a part of organizations support which general company's operating in CDP.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.408-413
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• 2006

Recently, the economic trend of internal enterprises toward the world market appears to exceedingly associate with industrial plants. Such circumstance would limit the diversity of project items and cause various issues of extreme disproportion of overseas construction market at the same time. Consequently, it seems essential to inspect the present state of bookings in the civil engineering and construction fields including the service corps, regarding the former period (from the year 1990 to 1996), the depressed period (from 1997 to 2000), and the latter period of monetary crisis (from 2001 to July 2006), based on the critical situation in foreign exchange occurred in the late 1990's; also important to look into the shifts of the representative items in such fields by regional groups of principal nations throughout the world. Therefore, the current situation of bookings in overseas construction companies should be clarified, and ultimately, appropriate measures should be established.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.620-627
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• 2017

An open sharing market is a market providing a sharing business. It provides open sharing services handling various products, unlike existing sharing services providing specific products. Sharing under an open sharing market can include all products that are difficult for customers to deal with, and provides fluidity of trade through negotiating sharing periods and costs among sharers. There are many variant elements when you provide sharing services for various products. Therefore, in this paper, we propose an extensible architecture that can reflect the variant elements in open sharing markets. We expect the proposed architecture can continuously improve the extensibility of sharing services for various products, because we design sharing services as components to efficiently manage and provide various sharing services, and provide dynamic binding of variant elements.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.279-279
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• 2011

나노 입자를 이용한 비휘발성 메모리 소자의 전기적 특성 향상을 위하여 일함수가 Si 보다 큰 금속, 금속산화물, 금속 실리사이드 나노입자를 이용한 다양한 형태의 메모리 구조가 제안되어져 왔다.[1] 특히 이와 같은 나노 부유 게이트 구조에서 터널 절연막의 구조를 소자의 동작 속도를 결정하는데 이는 터널링 되어 주입되는 전자의 확률에 의존하기 때문이다. 양자 우물에 국한된 전하가 누설되지 않으면서 주입되는 전자의 터널링 확률을 증가시키기 위하여, dielectric constant 와 barrier height를 고려한 다양한 구조의 터널 절연막의 형태가 제안 되었다.[2-3] 특히 낮은 전계에서도 높은 터널링 확률은 메모리 소자의 동작 속도를 향상시킬 수 있다. 본 연구에서는 n형 Si 기판위에 Si3N4 및 HfAlO를 각각 1.5 nm 및 3 nm 로 atomic layer deposition 방법으로 증착하였으며 3~5 nm 지름을 가지는 $TiSi_2$ 및 $WSi_2$ 나노 입자를 형성한 후 컨트롤 절연막인 $SiO_2$를 ultra-high vacuum sputtering을 사용하여 20 nm 두께로 형성 하였다. 마지막으로 $200{\mu}m$ 지름을 가지는 Al 전극을 200 nm 두께로 형성하여 나노 부유 게이트 커패시터를 제작하였다. 제작된 소자는 Agilent E4980A precision LCR meter 및 HP 4156A precision semiconductor parameter analyzer 를 사용하여 전기용량-전압 및 전류-전압 특성분석을 하여 전하저장 특성 및 제작된 소자의 터널링 특성을 확인 하여 본 연구를 통하여 제작된 나노 부유 게이트 커패시터 구조가 메모리 소자응용이 가능함을 확인하였다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.4
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• pp.203-209
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• 2000

Mokpo coastal zone suffers from increase of tidal amplitude by the reclamation projects of Youngsan River Scadike, Youngam and Keumho Seawalls, resulting inundation oflower lands. Tidal records at Mokpo harbor show jumps just after each construction not only in the mcan high water level but also in extreme one. Thus the design water levels must be newly estimated by a frequency analysis with the data of period after the last construction. But this period is at most 6 years yet, which restrains the normal frequency analysis. In this paper, new approach of converting the past data to the present one by a numerical model is proposed. Converted 32 years and observed 6 years data enables normal frequency analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.27-36
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• 2018

Although the current evaluation system has been revised four times since it was revised in 1996, it is insufficient to utilize it as a basis for predicting the performance degradation from the long-term viewpoint and prioritization decision for the budget input due to the evaluation system limited to securing the structural safety. Therefore, this study proposes a new evaluation system suitable for the performance evaluation of conventional (ASSM) tunnels among the various types of existing road tunnels using Delphi technique and AHP technique. Since the existing evaluation systems and evaluation items in domestic and overseas are limited in scope of evaluation criteria, the survey was conducted in conjunction with closed questionnaires on existing items and open questionnaires for eliciting new items. The validity of the questionnaire results were verified and the performance evaluation factors suitable for conventional (ASSM) tunnels were derived. After calculating weighted value of the derived evaluation item using AHP technique, a new evaluation system is proposed to meet the characteristics of the ASSM tunnel, so that they can be used as reference materials for revising and supplementing detailed guidelines of performance evaluation in the future.

• Tuberculosis and Respiratory Diseases
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• v.63 no.6
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• pp.531-536
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• 2007

Wegener's granulomatosis is a systemic vasculitis of the medium and small arteries, as well as of the venules, arterioles, and occasionally large arteries, and primarily involves the upper and lower respiratory tracts and the kidneys. Renal symptoms of Wegener's granulomatosis are indistinguishable from those of vasculitis such as Henoch-$Sch\ddot{o}nlein$ purpura and microscopic polyangiitis. This case, though initially diagnosed as Henoch-$Sch\ddot{o}nlein$ purpura, was confirmed as Wegener's granulomatosis from a lung biopsy fifteen years after the initial diagnosis. We report this case with a review of the literature.