• The KIPS Transactions:PartD
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• v.15D no.3
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• pp.321-326
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• 2008

The software defects that are not found in the course of a project frequently appear during the conduct of the maintenance procedure after the complete development of the software. As the frequency of surfacing of defects during the maintenance procedure increases, the cost likewise increases, and the quality and customer reliability decreases. The defect rate will go down only if cause analysis and process improvement are constantly performed. This study embodies the defect tracking system (DTS) by considering the Pareto principle: that most defects are repetitions of defects that have previously occurred. Based on the records of previously occurring defects found during the conduct of a maintenance procedure, DTS tracks the causes of the software defects and provides the developer, operator, and maintenance engineer with the basic data for the improvement of the software concerned so that the defect will no longer be manifested or repeated. The basic function of DTS is to analyze the defect type, provide the measurement index for it, and aggregate the program defect type. Doing these will pave the way for the full correction of all the defects of a software as it will enable the defect correction team to check the measured defect type. When DTS was applied in the software configuration management system of the W company, around 65% of all its software defects were corrected.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.91-102
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• 2007

The long term success of periodontal treatment is dependent upon the effectiveness of the main-tenance care program after active treatment. The purpose of this study was to evaluate whether nutraceutical containing PRF-K2 as natural product from plant and seaweed has beneficial effects on clinical parameters, gingival crevicular fluid (GCF) volume and GCF cytokine levels during main- tenance phase after periodontal treatment. Among the generally healthy and non-smoking. moderate to severe chronic periodontitis patients during maintenance phase in Department of Periodontics, Chonnam National University Hospital, twenty eight patients took nutraceutical containing PRF-K2 (Oscotec Inc. Cheonan, Korea) for 3 months as experimental group and sixteen patients received only maintenance care as control group. Clinical examination and GCF collection were performed at baseline, 1, 2 and 3 months of experiment. Total amounts and concentrations of GCF IL-1{\beta}, IL-1ra and $PGE_2$ were evaluated using ELISA kit. In probing pocket depth, experimental group showed the tendency of more reduction than control group after 3 months of experiment. Sulcus bleeding index (SBI) and GCF volume were significantly decreased in experimental group(p<0.05), whereas they were increased in control group. GCF IL-1{\beta} level tended to decrease in both experimental and control group and IL-1ra concentration tended to increase in experimental group and to decrease in control group. IL-1ra/IL-1{\beta} ratio tended to increase in experimental group and to decrease in control group during experimental period. GCF $PGE_2$ amount did not show any change in experimental group and tended to increase in control group. These results suggest that nutraceutical supplement which contain PRF-K2 could improve perio-dontal condition during maintenance phase after periodontal therapy.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.31-39
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• 2011

More than sixty percentage of highway in South Korea were constructed by concrete pavements and more than half of the concrete pavements were twenty years or older. Maintenance and rehabilitation of aged cement concrete pavements required early transportation opening due to difficulty of preparing bypass roads, given South Korea's transportation condition and so far, mostly asphalt concrete overlay has been used. However, asphalt concrete pavement maintenance and rehabilitation is costly because of early damage and at the same time, it causes inconvenience to the road users. Recently, as an effective method of rehabilitation for aged cement concrete pavement, bonded concrete overlay is being attempted. Therefore, utilizing various data on year-by-year basis is needed to rationally analyze of the damage on asphalt concrete overlay and bonded concrete overlay is necessary. However, in South Korea database of Serviceability damage on asphalt concrete overlay and bonded concrete overlay does not exist. In this research, performance is evaluated by the LTPP (Long Term Pavement Performance) Data of U.S.A, which accumulated various damage data of asphalt concrete overlay and bonded concrete overlay. However, the pattern distress of asphalt concrete overlay and bonded concrete overlay are different. Therefore, the pavement distress data of each section is collected into database and distress are calculated PCI(Pavement Condition Index) in order to compare life of asphalt concrete overlay and bonded concrete overlay.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.377-386
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• 2001

In spatial database system, spatial view is supported for efficient access method to spatial database and is managed by materialization and non-materialization technique. In non-materialization technique, repeated execution on the same query makes problems such as the bottle-neck effect of server-side and overloads on a network. In materialization technique, view maintenance technique is very difficult and maintenance cost is too high when the base table has been changed. In this paper, the SVMT (Spatial View Materialization Technique) is proposed by using R-tree re-construction. The SVMT is a technique which constructs a spatial index according to the distribution ratio of objects in spatial view. This ratio is computed by using a SVHR (Spatial View Height in R-tree) and SVOC (Spatial View Object Count). If the ratio is higher than the average, a spatial view is materialized and the R-tree index is re-used. In this case, the root node of this index is exchanged a node which has a MBR (Minimum Boundary Rectangle) value that can contains the whole region of spatial view at a minimum size. Otherwise, a spatial view is materialized and the R-tree is re-constructed. In this technique, the information of spatial view is managed by using a SVIT (Spatial View Information Table) and is stored on the record of this table. The proposed technique increases the speed of response time through fast query processing on a materialized view and eliminates additional costs occurred from repeatable query modification on the same query. With these advantages, it can greatly minimize the network overloads and the bottle-neck effect on the server.

• Korean Institute of Interior Design Journal
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• v.26 no.4
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• pp.42-56
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• 2017

In Korea, which has three sides of the sea, various waterfront spaces are being developed and developed along with various coastal landscapes. However, there are a lot of cases that do not consider the regional characteristic of the coast or the characteristic of the coastal landscape. In many cases, the street facilities cause the landscape degradation and the use inconvenience because of incongruity with the scenery, aging and lax management. Therefore, it is necessary to reflect the specificity of the coastal landscape in planning and directing the street facilities, harmonizing with the surrounding natural environment, and consideration of sustainability. However, there is no research or planning index for sustainable street facilities considering the coastal characteristics. Therefore, this study suggests plan elements to improve the sustainability of the street facilities on the shore and proposes them as basic plan elements, and suggests what kind of improvements should be made to improve the sustainability of coastal facilities in Korea. Based on the plan elements derived from the plan, we checked the problems and complementary points of coastal street facilities in Korea by analyzing the current status of the street facilities around the Jeju Island beach from a sustainable point of view, and suggested plan indicators that should be supplemented to improve sustainability. We surveyed the street facilities such as walkway blocks, benches, pagoda, drinking fountain, trash cans, bicycle shelters, fences, guide maps, streetlights, and shower rooms in 10 beaches in Jeju Island. This study analyzed the sustainability characteristics of the each factor of these facilities by surveying the reflectivity of the 23 plan indicators from the six aspects derived from the sustainability planning factor as conformity, partial reflection, non - reflection, and nonconformity. The results of the analysis showed that the functional aspect was the highest with 68.3%, the material aspect (53%), the landscape aspect (22.3%), the productive aspect (14.7%) and the morphological aspect (12.2%), and maintenance / management (10.6%). In addition, the facilities with the lowest fitness in each aspect are bicycle shelter in landscape aspect, bicycle storage box and trash can in form aspect, shower room in material aspect, trash can in functional aspect, showroom, guide maps and drinking fountain in product aspect, showroom In maintenance aspect. In order to improve the sustainability of coastal facilities in the future, it is necessary to complement the administrative and landscape aspects. In coastal facilities, it is necessary to consider the sustainability planning index, especially for showers, taking into account the specificity of beaches. Consideration should be given to various aspects of sustainability for bike shelters and trash facilities. Through this study, we have proposed the plan elements to systematize, supplement, and improve the planning index for sustainability improvement in coastal facilities planning.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.91-99
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• 2017

The purpose of this paper is to evaluate the flexural performance of reinforced concrete (RC) beams repaired with polymer mortar. The repaired and non-repaired 13th beams which was fabricated by considering repair position, repair depth, and curing age of polymer mortar as test variables were tested under three point loading. All specimens repaired in compressive and tensile zone did not fail due to interfacial failure between polymer mortar and concrete but failed when the strain of repaired mortar exceeded the ultimate tensile strain of polymer mortar. Maximum load of specimens repaired in compressive zone was similar to that of non-repaired specimen, reference specimen. Additionally, their ductility index was higher than that of reference specimen. On the other hand, specimens repaired in tensile zone failed very brittlely and have a lower ductility index than reference specimen. Nonlinear analysis by using OpenSees was performed to predict the behavior of RC beam repaired with polymer mortar. Two dimension frame element was used to simplify an analysis model and fiber model was applied to consider the material non-linearity. It was confirmed from the analysis results that nonlinear analysis properly predicts the behavior of specimens repaired in compressive zone and overestimates the behavior of specimens repaired in tensile zone.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.243-253
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• 2011

This paper describes an analytical study on seismic performance of domestic reinforced concrete (RC) school building not designed by seismic provision. The seismic index and the seismic performance of the building were evaluated through Japanese standard and Midas Gen, respectively. Seismic index (Is) of the RC school buildings in the X-direction is below 0.4. Based on the seismic index, for seismic-strengthening the building, infill shear wall or steel brace with a capacity of 1,300 kN was used. According to nonlinear static analysis results, the contribution of the seismic-strengthening to the shear resistance of the school building was measured to be greater than 30%. However, as expected, shear strength of school building strengthened with infill wall dropt rapidly after peak load and much narrower ductile behavior range was observed compared to steel brace strengthened building. Also, the building strengthened with steel brace showed 30% larger spectral displacement than that strengthened with infill shear wall. In nonlinear dynamic analysis, for the time history analysis, the maximum displacement showed tendency to decrease as amount of reinforcement increased, regardless of strengthening method. It was recommended that variable soil properties and earthquake record should be considered for improving seismic performance of buildings in seismic zone.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.15-23
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• 2021

In this paper, service life for RC(Reinforced Concrete) substructure subjective to carbonation was evaluated through deterministic and probabilistic method considering field investigation data and Design Code(KDS 14 20 40). Furthermore changes in service life with increasing COV(Coefficient of Variation) and equivalent safety index meeting the same service life were studied. From the investigation, the mean and its COV of cover depth were evaluated to 70.0 ~ 90.0 mm and 0.2, respectively. With intended failure probability of 10.0 % and 70 mm of cover depth, service life decreased to 137 years, 123 years, and 91 years with increasing COV of 0.05, 0.1, and 0.2, respectively. In the case of 80 mm of cover depth, it changes to 179 years, 161 years, and 120 years with increasing COV. The equivalent safety index meeting the same service life from deterministic method showed 1.66 ~ 3.43 for 70 mm of cover depth and 1.61 ~ 3.24 for 80 mm of cover depth, respectively. The various design parameters covering local environment and quality condition in deterministic method yields a considerable difference of service life, so that determination of design parameters are required for exposure conditions and parameter variation.

• Journal of the Korean housing association
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• v.18 no.3
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• pp.63-72
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• 2007

The purpose of this study is to identify the impact of the building, site, and region characteristic factors on the annual average price rising rate of apartment housing in Seoul. The data were consisted of 272 apartment units in Seoul. A survey included checking the drawing documents and interview with apartment maintenance staffs and real estate agencies from October 2006 to February 2007. Data were analyzed with descriptives, frequency, crosstabs, and linear regression by SPSS/PC for Window. The linear regression model was employed to evaluate the price rising rate in apartment housing. Following results were obtained. The price rising rate for pyeong ($3.3m^2$) of apartment housing was determinated by the district zone, the construction company's brand name, the building age, the building stories, the floor space index, the building-to-land ratio, the green space rate, and the distance from the downtown. Especially, the district zone was the most important factor that affected the price rising of apartment housing in Seoul. Therefore, the policy has to focus to solve the imbalance between autonomous districts with the collaborated tax.

• Journal of Technology Innovation
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• v.14 no.1
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• pp.67-99
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• 2006

Utilizing the patent application data between 1997 and 2002, this study focuses on analysing the impact of patents on firm value. Especially we attempt to examine the difference of patents between venture firms and general firms. This paper first shows that the number of the patent applications of general firms listed on the securities market is more than that of venture firms listed on KOSDAQ. It is thought that this result is originated from the facts that the size of firms of the securities market is usually bigger than that of the firms of KOSDAQ and that these large firms could manage R&D more efficiently. Second, this paper reports that there is no difference in the ratio of patent maintenance between venture firms and general firms. Both venture firms and non-venture firms would do their best to keep their patents after patent regisration. Third, in the regression of patent index and firm growth, we find that the excellence of patent and the number of patents per employee would have an impact on the growth of firms. Fourth, the regression of patent index and profitability shows that the excellence and the number of patents per employee might have an effect on the profitability of firms.