• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.36-46
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• 2009

The objective of this study is to analyze the effect of artificial soil ground on a structure. When the artificial soil ground is planted, the technical factors to be considered will be the load for buildings and the growth of plants. There are no current studies of the effect of artificial soil ground on a structure and this study will analyze the load effects of artificial soil ground, which mixes both pearlite and natural soil on structures. The load affecting the structures due to artificial soil ground will be maximized when the artificial soil ground becomes saturated, and which would occur when the rainfall intensity exceeds the infiltration capacity of the artificial soil ground. In order to determine whether the artificial soil ground has reached saturation or not, a 10 years frequency and 10 minutes rainfall intensity which is used for in urban drain design, is utilized. The hydraulic conductivity of artificial soil and mixed soil has been changed depending on the proportion of the mix, It has a range of fluctuation in the degree of hardening, in particular, but does not exceed the 10 minutes rainfall intensity over 10 years frequency in the most cases. Therefore, it would be efficient to apply the saturated unit weight of artificial soil ground as the design load of a structure.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.91-98
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• 2004

This study focuses on the development of dynamic assignment for evaluation and application for dynamic route guidance strategy. Travelers are classified according to information contents which they received pre/on trip. The first group have no traffic information, so they travel with fixed route. The second group have real-time shortest path and travel according to it. The last group have car navigation system or individual method(cellular phone, PDA-two way communication available) for traffic information on trip. And then they are assigned in accordance with the proposed multiclass dynamic assignment model. At this time the last group is gotten under control with DFS(decentralized feedback strategy). In use of this Process we expect that various traffic information strategy can be tested and also be the key factor for success of ITS, location of VMS(variable message sign), cycle of information, area of traffic information, etc).

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.2
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• pp.43-53
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• 2017

This study aims to analyze the effect of typhoons on pear production. Pears are typical fruits that are vulnerable to typhoon damages, so typhoons are negatively associated with pear productivity. However, relatively less pear damages by typhoons in the main pear production area, comparing to the average in Korea, have been reported. The main production area seems to adopt better agricultural techniques or practices to cope with natural disasters such as typhoons. Thus, this study tests the hypothesis that there are differences of production losses due to typhoons between the main pear production area and the rest using the stochastic frontier analysis. The main production area is defined by Location Quotient Index (LQI), and we found that LQI had a significant effect to decrease the productivity losses in the main production areas, which shows that those production areas alleviated the pear production loss due to typhoons.

• Journal of the Korean Wood Science and Technology
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• v.16 no.1
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• pp.21-44
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• 1988

As a way for the effective utilization of pallman chips and sawdusts, these furnish materials were combined with non-woody material of plastic (polypropylene) screen in board manufacturing to improve their weak physical and mechanical properties. The conventional boards were made with conditions of specific gravity 0.40, 0.55, 0.70, and 0.85, resin content 8, 10, 12 and 14%, and number of polypropylene screen 1, 2, 3 and 4, and press-lam boards were also manufactured. The physical and mechanical properties were measured and discussed on thickness swelling, bending modulus of rupture and elasticity, tensile strength, internal bond strength, and screw holding strength. The results obtained at this study were summarized as follows: 1. In thinckness swelling both of pallman chip board and sawdust board were improved by the increase of resin content, and press-lam boards showed lower thickness swelling than conventional boards. 2. Both the modulus of rupture and elasticity were increased with the increase of specific gravity, and press-lam boards showed higher modulus of rupture and elasticity than conventional boards. On the other hand, modulus of rupture was increased with the increase of number of polypropylene screen and resin content whereas these effects in modulus of elasticity was not recognized. 3. Tensile strength was increased with the increase of specific gravity, and the boards combined with polypropylene screen showed higher tensile strength than control boards. Also tensile strength was increased with the increase of number of polypropylene screen, and press-lam boards revealed higher tensile strength than conventional boards. 4. Internal bond strength was increased with the increase of specific gravity, and the boards combined with polypropylene screen were lower in internal bond strength than control boards. Also, the boards combined with odd number of polypropylene screen showed lower internal bond strength than those combined with even number of polypropylene screen. 5. Screw holding strength was increased with the increase of resin content and specific gravity but significant difference was not approved between boards combined with polypropylene screen and control boards. In press-lam boards, pallman chip boards of higher specific gravity but sawdust boards of lower specific gravity showed better screw holding strength than control boards.

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.252-260
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• 2015

This paper describes the technical background for the Korean wildlife radiation dose assessment code, K-BIOTA, and the summary of its application. The K-BIOTA applies the graded approaches of 3 levels including the screening assessment (Level 1 & 2), and the detailed assessment based on the site specific data (Level 3). The screening level assessment is a preliminary step to determine whether the detailed assessment is needed, and calculates the dose rate for the grouped organisms, rather than an individual biota. In the Level 1 assessment, the risk quotient (RQ) is calculated by comparing the actual media concentration with the environmental media concentration limit (EMCL) derived from a bench-mark screening reference dose rate. If RQ for the Level 1 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 2 assessment, which calculates RQ using the average value of the concentration ratio (CR) and equilibrium distribution coefficient (Kd) for the grouped organisms, is carried out for the more realistic assessment. Thus, the Level 2 assessment is less conservative than the Level 1 assessment. If RQ for the Level 2 assessment is less than 1, it can be determined that the ecosystem would maintain its integrity, and the assessment is terminated. If the RQ is greater than 1, the Level 3 assessment is performed for the detailed assessment. In the Level 3 assessment, the radiation dose for the representative organism of a site is calculated by using the site specific data of occupancy factor, CR and Kd. In addition, the K-BIOTA allows the uncertainty analysis of the dose rate on CR, Kd and environmental medium concentration among input parameters optionally in the Level 3 assessment. The four probability density functions of normal, lognormal, uniform and exponential distribution can be applied.The applicability of the code was tested through the participation of IAEA EMRAS II (Environmental Modeling for Radiation Safety) for the comparison study of environmental models comparison, and as the result, it was proved that the K-BIOTA would be very useful to assess the radiation risk of the wildlife living in the various contaminated environment.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.59-66
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• 2008

This study is about manufacturing and producing girder, which is an essential component of bridge structure, in a composite of FRP + concrete. This has a higher competitive power in price than steel girder. The girder used in this study is made of glass fiber which has a lower elastic modulus than steel and thus has some technical limitations such as excessive deflection compared to steel girder and lack of production facilities in FRP production companies to make a large-section component material. Thus, this study suggested a section of a new module that will allow for applying a large section in order to solve the technical difficulties mentioned above and to secure low stiffness of FRP, developed a new FRP+concrete composite girder that is filled with the appropriate amount of concrete. To identify the structural behavior of this FRP+concrete composite girder, experiments were conducted to measure its flexural strength according to the difference in the strength of confined concrete and the existence of stud. The results of the flexural strength test confirmed the composite effect from confining concrete and the effect of increase in strength proportional to the strength of concrete. In developing FRP+concrete composite girder, NDT study was also conducted to analyze the interface characteristics of concrete and FRP.

• Journal of Service Research and Studies
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• v.3 no.2
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• pp.33-44
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• 2013

As the Internet and mobile services increase, the use of wired/wireless web contents services increase and the demand for various contents explosively grows. To survive in competitive market, and to minimize the errors and warnings for web accessibility and standardization, and then to maximize the web usability, the periodical evaluation for web site should be performed with the events of web marketing and campaign. Through the web evaluation, the errors for technical programming language and contents offering can be found and diagnosed. In this paper, the quantitative and qualitative evaluation method for web site providing web contents are presented, and the analytic results for the 138 home pages in domestic are evaluated to validate the quantitative methodology. The accessibility, standardization, and usability factor are adopted for the evaluation in which accessibility is evaluated for perceivable, operable, understandable, and robust discipline with K-WAH(Korea-Web Accessibility Helper) tool, the standardization are measured for the number of errors and warnings in technical language with the W3C validator, and finally the usability factor is analyzed for the number of visits, average visit duration, and bounce rate with Google Analytics. In addition to, the quantitative analysis is also performed with the consideration of cost for construction and operation of web site. From the results, in the case of total score of 100 in conversion with relative weight, the average and standard deviation are evaluated to be 55 and 14, respectively. The correlation analysis indicates that the coefficient is estimated as 0.058, and then correlation between the quantitative results and cost is evaluated to be a little positive.

• Journal of Korea Technology Innovation Society
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• v.10 no.4
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• pp.687-705
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• 2007

Nowadays it is more important to measure the technological impact of a concerned R&D technology on others, when deciding or selecting strategically, under the environment such as more complex, more uncertain and more costly. But there was very few of proper methods to measure quantitatively. So we studied on measuring the technological impact of one group of technologies on others, which means the flow of disembodied knowledge, using patent citation analysis. We reviewed the prior art of the measurement of technological impact, and designs the effective citation analysis method using patent information, analyzing the prior art of patent citation analysis method and ie index. Finally, we developed the disembodied knowledge flow matrix between technology groups, counting citation frequencies between them, using KISTI's US patent database(USPA) and the index to represent the technological impact to others using the developed matrix as well as the intrinsic nature of the technological groups clustering by network analysis. The results of this study is to present the insight of a technological impact on the others quantitatively and this study aims at using them to refer to R&D budgeting and decision making in case of R&D planning or to the basic information to understand technology conversion or fusion.

• Resources Recycling
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• v.28 no.3
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• pp.15-20
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• 2019

The recovery of struvite using nitrogen and phosphorus in wastewaters is useful for prevention of eutrophication and use as fertilizer, but there are theoretical and technical issues to be resolved. Through the detailed literature review, this study discusses the possible reasonable prediction of struvite formation reaction by setting a feasible reaction equation with some theoretical considerations. In a technical aspect, the purity of struvite in solid precipitates can be promoted by excluding Ca in an effective way. As for the struvite reaction prediction issue, selection of proper equilibrium reaction as well as its reaction equilibrium coefficient is significant in the neutral and basic pH regions. The equilibrium reaction agrees well with the experimental batch test results. Considering the charge balance of the ions, the pH drop along struvite formation in a diluted solution can be predicted. Also, improvement of struvite purity through elimination of Ca can be expected by providing a highly concentrated ${NH_4}^+-N$ relative to ${HPO_4}^{2-}-P$ because ${NH_4}^+$ can enhance the thermodynamic driving force toward favorable struvite formation. Even though the phosphate reacts rapidly with Ca to form a solid precipitate, the thermodynamic driving force due to the high ${NH_4}^+$ activity can dissociate the phosphate-calcium precipitates and produce struvite.

• Journal of Internet Computing and Services
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• v.14 no.1
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• pp.23-30
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• 2013

Test effort estimated so far is as a by-product of the development effort estimation activity which is based on the FP, UCP, COCOMO model, or calculated data from the project knowledge base which is containing test effort information for the test phase on software development life cycle. In this paper, test effort estimation model and calculating procedures are suggested, which is independent from software development effort estimation model. Generally test efforts is depends on the number and the complexity of test cases, and also maturity of test organization that performs test activities, such as integration test, system test, acceptance test and so on. The estimated results with the suggested test effort estimation model has deviation of 4.7% compare to the corresponding test efforts generated by the development effort estimationprocedures. The suggesting model will be accurate more and more with refinements of coefficients which reflect the technical and environmental maturity level of test organization, and also including the software complexity level of projects.