• Tunnel and Underground Space
• /
• v.16 no.2 s.61
• /
• pp.109-134
• /
• 2006

Rocks undergo weathering processes influenced by changing in pressure-temperature condition, atmosphere, underground water, and rainfall. The weathering processes change physical and chemical characteristics of the rocks. Once the rocks are weathered, the characteristics of them are changed and, because of the changing, several disadvantages such as rock slope failures and underground water spouts are can occur. Before we cut a large rock slope, therefore, we must analyze current weathering conditions of rocks and predict weathering processes in the future. Through the results of such analyses, we can judge reinforcement works. In order to comply with such requests, chemical weathering sensitivity analysis which was analyzed from chemical weathering velocities and other characteristics of rocks has been applied in several prior construction works in Korea. But, It is defective to use directly in engineering fields because it was developed for soils(not rocks), it has too mny factors must be considered and the relationships between the factors are not clear, and it is hard to explain the weathering processes in engineering time range. Besides above, because it has been used for isotropic rocks, this method is hard to apply to anisotropic rocks such as sedimentary rocks. Acceding to studies from morphologists (e.g. Oguchi et al., 1994; Sunamura, 1996; Norwick and Dexter, 2002), time dependent strength reduction influenced by weathering shows a negative exponential function form. Appling this relation, one can synthesize the factors which influence the weathering processes to the strength reduction, and get meaningful estimates in engineering viewpoint. We suggest this weathering sensitivity characterization method as a technique that can explain time dependent weathering sensitivity characteristics through strength changes and can directly applied the rock slope design.

• Journal of Chest Surgery
• /
• v.31 no.7
• /
• pp.643-649
• /
• 1998

Background: For the patient with chronic obstructive pulmonary disease requiring long-term oxygen therapy, oxygen concentrator machines are already widely available for use in home. In this study, we used mongrel dogs as test subjects to compare the functional efficiency and safety of the oxygen concentrator developed by our own research team with those of the imported FORLIFE(TM) machine made by AIRSEP Corp. Method and method: To test mechanical reliability, the concentrations of oxygen delivered were measured after 4 hours of continuous operation. Sixteen mongrel dogs were divided into two equal groups. Mongrel dogs in group A were given oxygen using the imported oxygen concentrator, and those in group B using the machine developed. 5 l/min of oxygen were given, after which vital signs were analyzed, arterial blood gases measured, and blood chemistry tests carried out. Results: After 4 hours of continuous operation, the imported model performed better, giving 98${\pm}$3% oxygen, compared to our model, which gave 91${\pm}$1%. In the animal experiments, oxygen concentrations were measured at the inlet of face mask 1, 2, 3, and 4 hours after continuous administration, and there was no statistically significant difference(repeated measures of analysis of variance p=0.70) between the values of 70.6${\pm}$2.5%, 67.1${\pm}$2.9%, 68.2${\pm}$2.6%, and 64.9${\pm}$3.9% that were measured from group A, and the values of 65.1${\pm}$4.8%, 65.2${\pm}$3.6%, 68.7${\pm}$4.3%, and 66.0${\pm}$5.0% measured from group B. Before oxygen administration, and at 1, 2, 3, and 4 hours after oxygen administration, arterial blood partial pressure of oxygen 87.2${\pm}$2.5 mmHg, 347.4${\pm}$29.3 mmHg, 353.4${\pm}$21.2 mmHg, 343.0${\pm}$28.8 mmHg, and 321.6${\pm}$24.4 mmHg, respectively, were read from group A, which were not statistically different (p=0.24) to the values of 102.5${\pm}$9.6 mmHg, 300.3${\pm}$17.1 mmHg, 321.6${\pm}$23.7 mmHg, 303.4${\pm}$27.4 mmHg, and 273.5${\pm}$25.9 mmHg read from group B. Nonetheless, the arterial blood partial pressure of oxygen values appear to be somewhat higher in dogs that were given oxygen using the imported oxygen concentrator. Conclusions: From these results the prototype oxygen concentrator developed appears to function relatively satisfactorily compared to the imported, established model, but may be criticized for the excessive noise generated and poor long-term endurance or consistency, which need improvement.

• Journal of Chest Surgery
• /
• v.39 no.2 s.259
• /
• pp.134-139
• /
• 2006

Background: Complications after surgery for esophageal cancer are various and not rare. Among them, pulmonary complication is well known as one of the most important insults which has negative influence on the postoperative course and results in mortality. So we attempted to analyze the factors which may have relation to postoperative pulmonary complication. Material and Method: The retrospective study was undertaken in 87 patients who underwent curative surgery for esophageal cancer from Jan. 1996 to Aug. 2005. We divided them into two groups, patients with pulmonary complication (group A, n=28), without pulmonary complication (group B, n=59). Statistical analysis was performed with Fisher's exact test. Result: The postoperative pulmonary complication developed in 28 patients ($32\%$). There was no difference between two groups in past medical history, preoperative pulmonary function, surgery time, anastomosis method, pathologic stage, and trial of neoadjuvant therapy. Age and incidence of cervical anastomosis were significantly higher in group A (p=0.001, p=0.023). The rate of routine postoperative ventilator care was significantly higher in group S (p=0.007). Chest tube indwelling time and hospital stay were significantly longer in group A (p=0.011, p=0.001). There were 6 postoperative deaths ($6.8\%$) and 5 deaths were related to pulmonary complication. Pneumonia was the most common cause of death and MRSA (methicillin resistant staphylococcus aureus) was the most common organism in sputum culture. Conclusion: Pulmonary complication after esophageal cancer surgery was the most important cause of death. Pulmonary complication was closely related to patient's age and cervical anastomosis. We think postoperative routine ventilator care is helpful for prevention of pulmonary complications, especially MRSA pneumonia, and reducing mortality.

• Korean Journal of Ecology and Environment
• /
• v.33 no.3 s.91
• /
• pp.187-196
• /
• 2000

This paper describes a simple method that uses differences among Carlson's (1977) trophic state index (TSI) values based on total phosphorus (TP), chlorophyll a (CHL) and Secchi depth (SD) to draw inferences regarding the factors that are limiting to phytoplankton growth and the composition of lake seston. Examples are provided regarding seasonal and spatial patterns in a large subtropical lake (Lake Okeechobee, Florida, USA) and inter- and intra-lake variations from a multilake data set developed from published studies. Once an investigator has collected routine water quality data and established TSI values based on TP, CHL, and SD, a number of inferences can be made. Additional information can be provided where it also is possible to calculate a TSI based on total nitrogen (TN). Where TSI (CHL)<>TSI (SD), light attenuating particles are large (large filaments or colonies of algae), and the phytoplankton may be limited by zooplankton grazing. Other limiting conditions are inferred by different relationships between the TSI values. Results of this study indicate that the analysis is quite robust, and that it generally gives good agreement with conclusions based on more direct methods (e.g., nutrientaddition bioassays, zooplankton size data, zooplankton removal experiments). The TSI approach, when validated periodically with these more costly and time-intensive methods, provides an effective, low cost method for tracking long-term changes in pelagic structure and function with potential value in monitoring lake ecology and responses to management.

• Management & Information Systems Review
• /
• v.24
• /
• pp.125-154
• /
• 2008

The purpose of this study is to analyze how the organizational structure, task group functioning and need styles have influence on the conflicts handling styles such as integrating, avoiding, dominating, obliging and compromising as the employee's personality engaged in the service industry. This study uses the hierarchical regression analysis method. Data were collected by the survey method from employees engaged in the service industry located Seoul, the Province of Gyeonggi, and the Province of Gangwon. The study result shows that to the employees with the type A style, need styles are significantly related to the conflicts handling styles such as avoiding. But to the employees with the type B style, need styles are significantly related to the conflicts handling styles such as integrating and avoiding. On the other hand the result shows that the higher the need for achievement and the lower the need for autonomy, employees with the type B style prefer integrating styles to other conflicts handling styles. Or the higher the need for dominance, employees with the type B style prefer dominating styles to other conflicts handling styles. And the higher the need for dominance, employees with the type A style prefer dominating styles to other conflicts handling styles. The study result shows that to the employees with the type A and type X style, task group functioning are significantly related to the conflicts handling styles such as obliging and compromising. But to the employees with the type B style, task group functioning are significantly related to the conflicts handling styles such as obliging and dominating. On the other hand the result shows that the lower faith in peers and management and the higher confidence in peers and management, employees with the type B style prefer obliging style to other conflicts handling styles. But the higher group homogeneity and group cohesiveness, the lower faith in peers and management and the higher confidence in peers and management, employees with the type X style prefer obliging style to other conflicts handling styles. And the higher confidence in peers and management, employees with the type A style prefer compromising style to other conflicts handling styles. The study result shows that to the employees with the type A, organizational structure functioning are significantly related to the conflicts handling styles such as avoiding, obliging and compromising. But to the employees with the type X style, organizational structure functioning are significantly related to the conflicts handling styles such as dominating. On the other hand the result shows that the higher role conflict, the lower role ambiguity and the higher communication system, employees with the type A style prefer avoiding style to other conflicts handling styles. But the lower role ambiguity, employees with the type X style prefer compromising style to other conflicts handling styles. To conclude from these results, employees with the type A style have influence on the organizational structure functioning to other factors on the preference of the conflicts handling styles. And employees with the type B style have influence on the needs styles to other factors on the preference of the conflicts handling styles. Or employees with the type X style have influence on the task group functioning to other factors on the preference of the conflicts handling styles. Although this study provides several managerial implications, this study has some limitations. Specifically data were collected from only the service industry in Seoul, the Province of Gyeonggi, and the Province of Gangwon. In spite of the limitations, the study results could be used valuably in case of the personnel managers which manage the employees under the conflict situations.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.2
• /
• pp.109-120
• /
• 2017

A discounted cost model for preventive maintenance of armor units of rubble-mound breakwaters is mathematically derived by combining the deterioration model based on a discrete-time stochastic process of shock occurrence with the cost model of renewal process together. The discounted cost model of condition-based maintenance proposed in this paper can take into account the nonlinearity of cumulative damage process as well as the discounting effect of cost. By comparing the present results with the previous other results, the verification is carried out satisfactorily. In addition, it is known from the sensitivity analysis on variables related to the model that the more often preventive maintenance should be implemented, the more crucial the level of importance of system is. However, the tendency is shown in reverse as the interest rate is increased. Meanwhile, the present model has been applied to the armor units of rubble-mound breakwaters. The parameters of damage intensity function have been estimated through the time-dependent prediction of the expected cumulative damage level obtained from the sample path method. In particular, it is confirmed that the shock occurrences can be considered to be a discrete-time stochastic process by investigating the effects of uncertainty of the shock occurrences on the expected cumulative damage level with homogeneous Poisson process and doubly stochastic Poisson process that are the continuous-time stochastic processes. It can be also seen that the stochastic process of cumulative damage would depend directly on the design conditions, thus the preventive maintenance would be varied due to those. Finally, the optimal periods and scale for the preventive maintenance of armor units of rubble-mound breakwaters can be quantitatively determined with the failure limits, the levels of importance of structure, and the interest rates.

• Archives of design research
• /
• v.12 no.2
• /
• pp.157-168
• /
• 1999

Stone in the Cho Sun Dynasty has been used as the material of industry arts, widely building materials and an important material for the artistic design. But it has been generally used as an use of practical living Product like, suban, a metal printing type, a fire place, a pillowcase, a pencil case, etc, and ornament with the quality of stone material and the aesthetic view. There are several problems as like size, quantity, delivery and processing method with the stne material according to its variety and selection. Accordingly it has been studied through the whole process of shape, a material selection of design and processing method as well as studying about small stone crafts which were manufactured in the Cho Sun Dynasty, considering these problems. Stone crafts in Cho Sun Dynasty has been widely used as a living tool. There was some what difference on manufacturing purpose on its technique of folk crafts of stone crafts, but, through the research of collected crafts, they were almost the same that social need, user's taste and hobby in those days were reflected in. In the result of analysis as dividing the stone crafts into daily living product, stationery and tool, the major of daily products have been manufactured with emphasis of practicability. And they have been manufactured from agalmatolite for the propose of use. further, kitchen product had no design due to the function and living products which has been used in the main living room has been carved with the decorative expression of the various form by using intaglic, relieve, inlaid technique, etc. For the stationery, it has been characterized with aesthetic point considering the decorative effects & selection of material in accordance with use. A material for manufacturing has been used in the range of agalmtolite, atopaz, a sapphire, white stone etc. As the result of this research, It was noticeable that there was the spleudidness on the expression of design and carving. It was also noticeable that black stone and guanite have been widely esed because it didn't need the delicacy as a tool.

• Restorative Dentistry and Endodontics
• /
• v.34 no.2
• /
• pp.130-136
• /
• 2009

The aim of this study was to develop a method for measuring the slumping resistance of flowable resin composites and to evaluate the efficacy using rheological methodology. Five commercial flowable composites (Aelitefil flow:AF, Filtek flow:FF, DenFil flow:DF, Tetric flow:TF and Revolution:RV) were used. Same volume of composites in a syringe was extruded on a glass slide using a custom-made loading device. The resin composites were allowed to slump for 10 seconds at $25^{\circ}C$ and light cured. The aspect ratio (height/diameter) of cone or dome shaped specimen was measured for estimating the slumping tendency of composites. The complex viscosity of each composite was measured by a dynamic oscillatory shear test as a function of angular frequency using a rheometer. To compare the slumping tendency of composites, one way-ANOVA and Turkey's post hoc test was performed for the aspect ratio at 95% confidence level. Regression analysis was performed to investigate the relationship between the complex viscosity and the aspect ratio. The results were as follows. 1. Slumping tendency based on the aspect ratio varied among the five materials (AF

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.30 no.1
• /
• pp.57-65
• /
• 2012

This work attempted to study the properties of expression of ground, the composition of outlook and the implications of the connotative symbolic scenery throughout investigating the properties of expression content and method of the scenery, outlook, viewpoint, natural features for each drawing and intention of making 4 old maps, which had been made in the period of the Great Korean Empire and had been called 'Wansan-dohyoung(完山圖形),' 'Jogyeongdan- bigak-jaesil-dohyoung(肇慶壇碑閣齋室圖形),' 'Jeonju-geonjisan-dohyoung(全州乾止山圖形)' and 'Jogyeongmyo-gyounggijeon-dohyoung(肇慶廟慶基殿圖形),' and analyzing the correlation between their drawings. For this aim, observatory investigation by using a map, on-spot investigation, analysis involving the satellite images and internet were carried out with literature review simultaneously. The result of investigation could be sum up as follows. Gyounggijeon(1410), Jogyeongmyo(1771) and Jogyeongdan(1899), where are the core space to lay the historically firm foundation for securing the fact Jeonju is the home of the Royal Family of Joseon, had been built, fixed and extended for giving legitimacy to the Joseon Dynasty and a part of strengthening of royal authority. And these had played an important role of spiritual mainstay from early in the Joseon Dynasty to the era of the Great Korean Empire and had been managed and maintained continuously. It is grasped that the 4 maps consist of Sanhyuoungdo(山形圖; a kind of a mountain map), which is the map for showing a burial place of Lee Han(李翰), the founder of the Joseon Dynasty, and its auxiliary drawings and these had been drawn intensively to justify dignity and authority of the Imperial Family and the Emperor after the name of country was renamed the Great Korean Empire as a part of national undertaking. In detail, Wansan-doghyoung is the key map for announcing the existence of Jogyeong-myo, Gyounggijeon and Jogyeongdan in Jeonju and informing their locations and Geonjisan-dohyoung is the map of divination based on topography for highlighting the geomantic justification of the founder's mausoleum. Jogyeongdan-bigak-jaesil-dohyooung is the partial map detailing for Geonjisan-dohyoung. Jeonju-geonjisan-dohyoung and Jogyeongmyo-gyounggijeon-dohyoung had employed the binary reduced scale and the bird-eye view method and in the above maps, Geonji Mountain is the main mountain and these maps make an exaggeration of the main geographical features, centering Wangjabong and Euimyoso, unlike the real geographical features. Also, the other main geographical features, which are found in the burial place, are expressed in detail by changing the view. In the point of view of 1 set being consisted of 4 maps, 'Wansan-dohyoung' has the property not only as Gunhyoundo, which Gun and Hyoun mean a unit of the administrative district, respectively and Gynhyoundo is a kind of the map for recording their locations, but also as the map of showing their locations. On the other side, 'Jogyoungmyogyounggijeondohyoung' is a kind of lay-out drawing as a partially detailed map. In addition, it has been found out that 'Jeonju-geonjisan-dohyoung' and 'Jogyeongdan-bigak-jaesil-dohyoung' is not only Pungsu- hyounggukdo having the function of Sanhyoungdo but also a detail drawing. On the base of these properties, it is considered that the functionality as a serial map had been strengthened, unlike the existing old maps.

• Journal of Distribution Science
• /
• v.7 no.4
• /
• pp.47-56
• /
• 2009

The purpose of this study is to present an alternative improving the efficient and reasonable of the physical distribution system management is influenced by many factors. Therefore, the study depends on the documentary method and survey method to achieve the purpose of this study. The major components of a physical distribution system are refers to as elements, include warehouse·storage system, transportation system, inventory system, physical distribution information system. The factors used in this study are ① factor of product(quality·A/S·added value of product·adaption of product·technical competitive power to other enterprises), ② factor of market(market channel·kinds of customer·physical distribution share), ③ factor of warehouse·storage(warehouse design·size·direction·storage ability·warehouse quality), ④ factor of transportation(promptness·reliability·responsibility·kinds of transportation·cooperation united transportation system·national transportation network), ⑤ factor of packaging (packaging design·material·educating program·pollution degree measure program), ⑥ factor of inventory(ordinary inventory criterion·consistence for inventories record), ⑦ factor of unloaded(unloaded machine·having machine ratio), ⑧ factor of information system (physical distribution quantity analysis·usable computer part), ⑨ factor of physical distribution cost(sales ratio to product) ⑩ factor of physical distribution system(physical distribution center etc). The implication of this study can be summarized as follows: ① In firms that have not adopted a systems integrative approach, physical distribution is a fragmented and often uncoordinated set of activities spread throughout various functions with function having its own set of priorities and measurements. ② The physical distribution is recognized as more an important strategic factor than a simple cost reduction factor, ③ It can be used a strategic competition tool to enterprise.