• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.2
• /
• pp.24-37
• /
• 2012

In this study, Community Garden of various national and international practices trends to an advanced research, the concept of community garden participated with a group operation out of initiative to produce safety food while securing space for the community, ensuring the area that has gone through a new form of active secure urban green space plan, urban renewal movement was defined as the mean. Furthermore, for the purpose of improving the poor welfare environment by attempting to experimentally make a community garden of a disabled welfare house rooftop and how to target its planning and construction process, partnership involvement, business processes have been investigated, such as cost sharing. The whole process including a budget for development of this case was conducted by the Busan Green Trust. Standard Chartered (SC) First Bank's 50% fund share by community chest, participation of volunteers, support of Busan City and Saba-gu, outside of that, sharing parts or trial to participate by diverse partnership of enterprise, public corporation and laboratory, these are the key in developing community garden's model. Established community garden places resulted food production to users of welfare center for the disabled, participating urban agricultural experience program, horticultural therapy, complex community chapter and cultural center. Furthermore, we could find the meaning of rooftop community garden in the point that it is a low cost garden by applying movable and unmovable planters. This study is profitable for improving urban environment, ensuring community chapter and urban green areas, regenerating a city to develop experimental community garden model by using a welfare house rooftop.

• Journal of the Korean Institute of Navigation
• /
• v.4 no.2
• /
• pp.45-79
• /
• 1980

The aim of this paper is to analyze the mechanics of price formation in the tramp shipping. For the purpose of this study, the main characteristics of tramp freight rates and the market is examined, and a brief examination of the nature ofthe costs of operation is given which are essential for the understanding of the functioning of shipping firms as well as for the understanding of developments in the tramp freight market. The demand and supply relationships in the market is also analysed in detail. Tramp shipping is an industry that has a market which functions under conditions that are not dissimilar to the theoretical model of perfect competition. However, it does notmean that tramp shipping market is a perfectly competitive market. It is apparent that this realworld competitive system has its imperfections, which means that the market for tramp shipping is near to being a perfectly competitive market on an internaitonal scale and it is freight are therefore subjext to the laws of supply and demand. In theory, the minimum freight rate in the short term is that at which the lowest cost vessels will lay-up in preference to operating, and is equal to the variable costs minus lay-up costs; and this would imply that in all times except those of full employment for ships there is a tendency for newer low-cost, and, probably, faster vessels to be driving the older high-cost vessels in the breaker's yards. In this case, shipowners may be reluctant to lay-up their ships becasue of obligations to crews, or because they would lose credibility with shippers or financiers, or simply because of lost prestige. Mainly, however, the decision is made on strictly economic grounds. When, for example, the total operating costs minus the likely freight earnings are greater than the cost of taking the ship out of service, maintaining it, and recommissioning it, then a ship may be considered for laying-up; shipowners will, in other words, run the ships at freight earnings below operating costs by as much as the cost of laying them up. As described above, the freight rates fixed on the tramp shipping market are subject to the laws of supply and demand. In other words, the basic properties of supply and demand are of significance so far as price or rate fluctuations in the tramp freight market are concerned. In connection with the same of the demand for tramp shipping services, the following points should be brone in mind: (a) That the magnitude of demand for sea transport of dry cargoes in general and for tramp shipping services in particular is increasing in the long run. (b) That owning to external factors, the demand for tramp shipping services is capable of varying sharphy at a given going of time. (c) The demad for the industry's services tends to be price inelastic in the short run. On the other hand the demand for the services offered by the individual shipping firm tends as a rule to be infinitely price elastic. In the meantime, the properties of the supply of the tramp shipping facilities are that it cannot expand or contract in the short run. Also, that in the long run there is a time-lag between entrepreneurs' decision to expand their fleets and the actual time of delivery of the new vessels. Thus, supply is inelastic and not capable of responding to demand and price changes at a given period of time. In conclusion, it can be safely stated that short-run changes in freight rates are a direct result of variations in the magnitude of demand for tramp shipping facilities, whilest the average level of freight rates is brought down to relatively low levels over prolonged periods of time.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.3
• /
• pp.100-114
• /
• 2018

Nationally designated Cultural Properties 'Scenic site No.12 Maisan Mountain, Jinan' designated areas and some protected areas, and taking into account the dynamics of naturalized plants causing problems, we will restore the original vegetation scenery of Mt. Maisan. The results of this study are as follows. A total of 76 families, 192 genera, 286 taxa, and inland and inhabited areas, 76 and 138 genera and 163 taxa were identified in the areas of Ammaibong. The total number of naturalized plants identified in this study area is 28 taxa total, which corresponds to 7.1% naturalization rate(NR) among the vascular plants of all 395 taxa, and the urbanization index(UI) corresponds to 8.4% of the 333 taxa of Korean naturalized plants. Ecosystem disturbance plants identified in the survey area were Ambrosia artemisiifolia 1 taxa. The naturalized plants controlled and managed by separate anthropogenic vegetation management within the designation and protection area of Maisan scenic place are three species of herbaceous Rumex acetosella, A. artemisiifolia and Festuca arundinacea. It was identified as a breed. Indigofera bungeana and F. arundinacea communities around the stairway and Amorpha fruticosa, I. bungeana, A. artemisiifolia and Amaranthus patulus of the top of Am-Maibong were selected as the first priority sites for exclusion of exotic species in Maisan area and target naturalized plants species to the Ammaibong peak. In addition, R. acetosella community around the temple was suggested to be removed first to preserve endemic species. For the restoration of vegetation, we suggest that Stephanandra incisa, Spiraea blumei, Weigela subsessilis, etc. should be planted after removal of I. bungeana, and F. arundinacea, C. lanceolata, Carex callitrichos var. nana.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.3
• /
• pp.88-99
• /
• 2018

After UNESCO appointed Royal Tombs of the Joseon Dynasty to be World Cultural Heritages(2009), Cultural Heritage Administration in Korea established Management Office of Royal Tombs of the Joseon Dynasty(2012) and conducted Mid to Long-Term Plan on Conservation, Management, Utilization of World Heritage 'Royal Tombs of the Joseon Dynasty(2015)'. The report, as an implementation plan, provides detailed contents of the maintenance planning of Royal Tombs of the Joseon Dynasty. From this background, with a view to comprehending the characteristics of the maintenance planning of trees in historical landscape forests, this study extracted the contents related to the historical landscape forests of the 40 Royal Tombs of the Joseon Dynasty from the "Mid to Long-term Plan" and conducted literature research. The results of the study are as follows. First, from 2016, the short-term plans have provided detailed contents on logging, transplanting and planting trees in the plans divided by stages. On the other hand, the long-term plans, instead of presenting abstract contents repeatedly for each royal tomb, should seek vegetation landscape that each royal tomb should aim for. Second, since the areas that are in charge of the various functions of the royal tombs have been subjects to the maintenance planning, it is effective to establish a maintenance planning by separating functional areas instead of the comprehensive concept as historical landscape forests. Third, the maintenance planning of trees in historical landscape forest of the Royal Tombs of Joseon Dynasty is based on daily management such as density control and maintaining the shape of trees, which is necessary to sustain the forest. Also, due to the goal of preserving the pine forest, which is recognized as a prototype vegetation landscape, foreign species and other trees have been more cut down. With a few limited types of tall tree but few shrubs and flowers, it is characterized that the orientation toward aesthetic landscapes is insufficient in large green spaces. Fourth, according to the function of the tomb, it is divided into entrance area, ceremonial area, burial area and outer forest, and the contents of the maintenance planning are analyzed by basic conditions of tree management: prototype, ecology, functionality, and aesthetics. After studying the tree management characteristics of each area, four suggestions are made: understanding the diversity of trees that form prototype landscape as a management plan, sustainability of various forests adapted to ecological environment, convenience required in addition to ceremony and safety characterizing the Royal Tombs of Joseon Dynasty, and the necessity of access to aesthetic landscape on the tombs.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1572-1578
• /
• 2007

The specified wastes consist of waste acid, waste alkali, waste oil, waste organic solvent, waste resin, dust, sludge, infectious waste, and others. Among these specified wastes, a great portion is liquid phase wastes. The purpose of this study is to develop the high temperature and high pressure (HTHP) treatment system for decomposition of the liquid phase specified waste (LPSW). For this, we analyzed the physical and chemical properties of the LPSW such as density, proximate analysis, ultimate analysis, heating values, and designed 0.3 ton/day HTHP treatment system. The LPSW tested in this experiment were prepared by adding TCE(trichloroethylene) and toluene to liquid phase waste which was brought into the commercial waste treatment company. The average density of waste oil (25 samples), waste resin (5 samples), and waste solvent (12 samples) was 0.99 g/mL, 0.91 g/mL, and 0.93 g/mL, respectively. And the average lower heating value of waste oil, waste resin, and waste solvent was 8,294 kcal/kg, 5,809 kcal/kg, and 7,462 kcal/kg, respectively. The DRE (Destruction & Removal Efficiency) of TCE and toluene were 99.95% and 99.73% at atmospheric pressure conditions and that were 99.99% and 99.82% at pressurized conditions, respectively. These results showed that TCE/toluene mixtures were properly decomposed over about 99.73% of DRE by the HTHP treatment system and pressurized conditions were more effective to destroy those pollutants than atmospheric pressure conditions. Also these systems could be directly applied to industries which try to treat the liquid phase specified waste within the regulation limit.

• The KIPS Transactions:PartB
• /
• v.10B no.3
• /
• pp.281-286
• /
• 2003

A large number of features are collected for problem solving in real life, but to utilize ail the features collected would be difficult. It is not so easy to collect of correct data about all features. In case it takes advantage of all collected data to learn, complicated learning model is created and good performance result can't get. Also exist interrelationships or hierarchical relations among the features. We can reduce feature's number analyzing relation among the features using heuristic knowledge or statistical method. Heuristic technique refers to learning through repetitive trial and errors and experience. Experts can approach to relevant problem domain through opinion collection process by experience. These properties can be utilized to reduce the number of feature used in learning. Experts generate a new feature (highly abstract) using raw data. This paper describes machine learning model that reduce the number of features used in learning using heuristic function and use abstracted feature by neural network's input value. We have applied this model to the win/lose prediction in pro-baseball games. The result shows the model mixing two techniques not only reduces the complexity of the neural network model but also significantly improves the classification accuracy than when neural network and heuristic model are used separately.

• Restorative Dentistry and Endodontics
• /
• v.31 no.4
• /
• pp.323-329
• /
• 2006

The aim of this study was to evaluate the retrievability of Resilon as a root canal filling material Twenty-seven human single-rooted extracted teeth were instrumented utilizing a crown down technique with Gates-Glidden burs and ProFile system. In group1 (n = 12) canals were obturated with gutta percha and AH-26 plus sealer using a continuous wave technique and backfilled. In group 2 (n = 15) Resilon was used as a filling material. Then teeth were sealed and kept in $37^{\circ}C$ and 100% humidity for 7 days. For retreatment, the samples were re-accessed and filling material was removed using Gates-Glidden burs and ProFiles. Teeth were sectioned longitudinally to compare the general cleanliness and amount of debris $({\times}\;75)$ using SEM. Chi-square test was used $({\alpha}\;=\;0.05)$ to analyze the data. The total time required for removal of filling materials was expressed as mean ${\pm}SD$ (min) and analyzed by the Student t-test $({\alpha}\;=\;0.05)$, Required time for retreatment was $3.25\;{\pm}\;0.32$ minutes for gutta percha/ AH 26 plus sealer and $3.05\;{\pm}\;0.34$ minutes for Resilon. There was no statistically significant difference between the two experimental groups. There was no significant difference between the groups in the cleanliness of the root canal wall. This study showed that Resilon was effectively removed by Gates-Glidden burs and ProFiles.

• Restorative Dentistry and Endodontics
• /
• v.31 no.4
• /
• pp.263-268
• /
• 2006

Recently, self-etching adhesive system has been introduced to simplify the clinical bonding proce- dures. It is less acidic compared to the phosphoric acid, thus there is doubt whether this system has enough bond strength to enamel. The purpose of this study was to investigate the influence of additional etching on the adhesion of resin composite to enamel. Ninety extracted bovine permanent anterior teeth were used. The labial surfaces of the crown were ground with 600-grit abrasive paper under wet condition. The teeth were randomly divided into six groups of 15 teeth each. Clearfil SE $Bond^{\circledR},\;Adper^{TM}$ Prompt L-Pop and Tyrian $SPE^{TM}$ were used as self-etching primers. Each self-etching primers were applied in both enamel specimens with and without additional etching. For additional etching groups, enamel surface was pretreated with 32% phosphoric acid (UNI-ETCH, Bisco, Inc., Schaumburg, IL. USA). Hybrid resin composite Clearfil AP-X, (Kuraray Co., Ltd., Osaka, Japan) was packed into the mold and light-cured for 40 seconds. Twenty-four hours after storage, the specimens were tested in shear bond strength. The data for each group were subjected to independent t - test at p < 0.01 to make comparisons among the groups. In Clearfil SE $Bond^{\circledR}$, shear bond strength of additional etching group was higher than no additional etching group (p < 0.01). In $Adper^{TM}$ Prompt L-Pop and Tyrian SPE, there were no significant difference between additional etching and non-etching groups (p > 0.01). In conclusion, self-etching adhesive system with weak acid seems to have higher bond strength to enamel with additional etching, while self-etching adhesive system with strong acid seems not.

• Restorative Dentistry and Endodontics
• /
• v.31 no.4
• /
• pp.300-311
• /
• 2006

The purpose of this study is to evaluate prospectively the effect of different bonding systems and retention grooves on the clinical performance of resin restorations in non-carious cervical lesions (NCCLs). Thirty-nine healthy adults who had at least 2 NCCLs in their premolar areas were included in this study. One hundred and fifty teeth were equally assigned to six groups: (A) Scotchbond Multi-Purpose (SBMP, 3M ESPE, St. Paul, MN, USA, 4th generation bonding system) without retention grooves; (B) SBMP with retention grooves; (C) BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5th generation bonding system) without retention grooves; (D) BC Plus with retention grooves; (E) Adper Prompt (3M ESPE, Seefeld, Germany, 6th generation bonding system) without retention grooves; (F) Adper Prompt with retention grooves. All cavities were filled with a hybrid composite resin. Denfil (Vericom Co., Anyang, Gyeonggido, Korea) by one operator. Restorations were evaluated at baseline and at 6-month recall, according to the modified USPHS (United States Public Health Service) criteria. Additionally, clinical photographs were taken and epoxy resin replicas were made for SEM evaluation. At 6-month recall, there were some differences in the number of alpha ratings among the experimental groups. But, despite the differences in the number of alpha ratings, there was no significant difference among the 3 adhesive systems (p < 0.05). There was also no significant difference between the groups with or without mechanical retention (p < 0.05). Follow-ups for longer periods than 6 months are needed to verify the clinical performance of different bonding systems and retention grooves.

• Restorative Dentistry and Endodontics
• /
• v.24 no.2
• /
• pp.299-309
• /
• 1999

The composite resin, due to its esthetic qualities, is considered the material of choice for restoration of anterior teeth. With respect to shade control, the direct-placement resin composites offer some distinct advantages over indirect restorative procedures. Visible-light-cured (VLC) composites allow dentists to match existing tooth shades or to create new shades and to evaluate them immediately at the time of restoration placement. Optimal intraoral color control can be achieved if optical changes occurring during application are minimized. An ideal VLC composite, then, would be one which is optically stable throughout the polymerization process. The shade guides of the resin composites are generally made of plastic, rather than the actual composite material, and do not accurately depict the true shade, translucency, or opacity of the resin composite after polymerization. So the numerous problems associated with these shade guides lead to varied and sometimes unpredictable results. The aim of this study was to assess the color changes of current resin composite restorative materials which occur as a result of the polymerization process and to compare the color differences between the shade guides provided with the products and the actual resin composites before- and after-polymerization. The results obtained from this investigation should provide the clinician with information which may aid in improved color match of esthetic restoration. Five light activated, resin-based materials (${\AE}$litefil, Amelogen Universal, Spectrum TPH VeridonFil-Photo, and Z100) and shade guides were used in this study. Three specimens of each material and shade combination were made. Each material was condensed inside a 1.5mm thick metal mold with 10mm diameter and pressed between glass plates. Each material was measured immediately before polymerization, and polymerized with Curing Light XL 3000 (3M Dental products, USA) visible light-activation unit for 60 seconds at each side. The specimens were then polished sequentially on wet sandpaper. Shade guides were ground with polishing stones and rubber points (Shofu) to a thickness of approximately 1.5mm. Color characteristics were performed with a spectrophotometer (CM-3500d, Minolta Co., LTD). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$ and $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E{^*}ab$) of resin composites before the polymerization process and shade guides using the post-polishing color of the composite as a control, CIE standard D65 was used as the light source. The results were as follows. 1. Each of the resin composites evaluated showed significant color changes during light-curing process. All the resin composites evaluated except all the tested shades of 2100 showed unacceptable level of color changes (${\Delta}E{^*}ab$ greater than 3.3) between pre-polymerization and post-polishing state. 2. Color differences between most of the resin composites tested and their corresponding shade guides were acceptable but those between C2 shade of ${\AE}$litefil and IE shade of Amelogen Universal and their respective shade guides exceeded what is acceptable. 3. Comparison of the mean ${\Delta}E{^*}ab$ values of materials revealed that Z100 showed the least overall color change between pre-polymerization and post-polishing state followed by ${\AE}$litefil, VeridonFil-Photo, Spectrum TPH, and Amelogen Universal in the order of increasing change and Amelogen Universal. Spectrum TPH, 2100, VeridonFil-Photo and ${\AE}$litefil for the color differences between actual resin and shade guide. 4. In the clinical environment, the shade guide is the better choice than the shade of the actual resin before polymerization when matching colors. But, it is recommended that custom shade guides be made from resin material itself for better color matching.