• Journal of the Korean Geotechnical Society
• /
• v.20 no.7
• /
• pp.197-206
• /
• 2004

The ground anchor support system may not be occasionally used because of space limitations in urban excavation sites nearby the existing structures. In this case, soil nailing system with relatively short length of nails could be efficiently adopted as an alternative method. The general soil nailing support system, however, may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then could play important roles to reduce deformations mainly in the upper part of the nailed-soil excavation system as well as to improve local stability. In this study, a newly modified soil nailing technology named as the PSN (Pretension Soil Nailing), is developed to reduce both facing displacements and ground surface settlements in top-down excavation process as well as to increase the global stability. Up to now, the analytical procedure and design technique are proposed to evaluate maximum pretension force and stability of the PSN system. Also, proposed are techniques to determine the required thickness of a shotcrete facing and to estimate probability of a failure against the punching shear, Based on the proposed procedure and technique, effects of the radius of a influence circle and dilatancy angle on the thickness of a shotcrete facing, bonded length and safety factors are analyzed. In addition, effects of the reduction of deformations expected by pretension of the soil nails are examined in detail throughout an illustrative example and the $FLAC^{2D}$ program analysis. And a numerical approach is proposed PSN system using the shear strength reduction technique with the $FLAC^{2D}$ program.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.6 no.2
• /
• pp.171-185
• /
• 2000

The twenty-first century may be said to be entering into a specialized qualification age to meet the needs of new technical innovations such as environmental changes, demographical changes, changes in the constitution of diseases, changes in the needs of the national health, reforms of information and knowledge, etc., which requires the provision of competitive services that can fulfill the high level needs of consumers. In consequence, it is needed to apply a practical nursing model that can serve as a guide for healthy society and to secure the sphere that can affect nursing policy-making by keeping pace with the changing environment. Furthermore, it is also urgent to expand more the activity sphere of nurse specialists with authority and autonomy, establish their legal foundation, establish a qualification accreditation system for nurse specialists, and develop educational programs. In Korea, the law relative to organ transplant past the national assembly on February 9, 2000, legally acknowledged brain death, which indicated to us the emergence of an age of organ transplant. Therefore, it necessitates to find out those of brain death from whom organ transplant is feasible in clinical practices, with their families' consent link to those terminal organ failure patients who are in need of an organ, and mediate both parties so that smooth transplant can be accomplished. A series of these complicated procedures require systematically trained specialists with high level techniques of organic management. With this in mind, this study was conducted on 69 clinical nurse specialists for organ transplant, accredited by the hospital, who are in active service in clinical practices. The resultant findings were revealed, as follows: 1. The qualifications of clinical nurse specialists for organ transplant should be accredited by Ministry of Health and Welfare or Korea Nurses Association. 2. The validity of qualifications should be for three years, and their renewal should be based on marks of a supplemental training or an education course for more than 12 hours a year. 3. The qualification of the clinical nurse specialist necessitates theoretical lectures and practices on those nurses who have had clinical experience in the pertinent field. 4. The course of training is required to be one year in the length of training and take more than 20 credits (320 hours) and 5 credits (240 hours).

• Journal of Trauma and Injury
• /
• v.25 no.4
• /
• pp.247-253
• /
• 2012

Purpose: Hemorrhage is a main cause of death in trauma patients. The goal of this study is to describe the characteristics of trauma patients with massive bleeding and to evaluate the prognostic factors concerning their survival. Methods: This study was performed retrospectively and included trauma patients with massive bleeding who had been treated from March 2007 to August 2012. The inclusion criterion was patients who received more than 10 U of packed red blood cells within the first 24 hours after visiting the emergency department. Based on their medical records, we collected data in terms of demographic findings, mechanisms of injury, initial clinical and laboratory findings, methods for hemostasis (emergency surgery and/or angioembolization), transfusion, injury severity score (ISS), revised trauma score (RTS) and trauma and injury severity score (TRISS). We used the Mann-Whitney U test and Fisher's exact test to compare the variables between the patients that survived and those that did not. We performed a logistic regression analysis with the significant variables from the univariate test. Results: Thirty-two(32) patients were enrolled. The main mechanisms of injury were falls and motor vehicle accidents. The mean transfusion amount of packed red blood cells (PRBC) was 17.4 U. The mean elapsed time for the first hemostasis (surgery or embolization) was 3.5 hours. The initial technical success rates were 83.3%(15/18) in angioembolization and 66.7%(8/12) in surgery. The overall mortality rate was 34.4%(11/32). The causes of death were bleeding, brain swelling and multiple organ failure. The ISS(25.5 vs 46.3, p=0.000), TRISS(73.6 vs 45.1, p=0.034) and base excess(<-12 mmol/L, p=0.020) were significantly different between the patients who survived and those who did not. Conclusion: The ISS was a prognostic factor for trauma patients with massive bleeding.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.7
• /
• pp.19-29
• /
• 2013

Analysis via classical soil mechanics theory is either ineffective or inappropriate for fully describing stress distribution or failure conditions in cold regions, since mechanical properties of soils in cold regions are different from those reported in the classical soil mechanics theory. Therefore, collecting and analyzing technical data, and systematic and specialized research for cold regions are required for design and construction of the structure in cold regions. Freezing and thawing repeat in active layer of permafrost region, and a loading condition affecting the structure changes. Therefore, the reliable analysis of mechanical properties of frozen soils according to various conditions is prerequisite for design and construction of the structure in cold regions, since mechanical properties of frozen soils are sensitive to temperature condition, water content, grain size, relative density, and loading rate. In this research, the direct shear apparatus which operates at 30 degrees below zero and large-scaled low temperature chamber are used for evaluating shear strength characteristics of frozen soils. Weathered granite soil is used to analyzed the shear strength characteristics with varying freezing temperature condition, vertical confining pressure, relative density, and water content. This research shows that the shear strength of weathered granite soil is sensitively affected by various conditions such as freezing temperature conditions, normal stresses, relative densities, and water contents.

• Journal of the Korean Society of Safety
• /
• v.25 no.6
• /
• pp.34-39
• /
• 2010

The purpose of this study is to suggest objective evaluation model as a plan to utilize as opportunity in establishing judgment standard of mutual inspection criteria and to upgrade inspection ability by reviewing and analyzing level of danger and importance in advance based on inspection results of inspection institutions regarding tower cranes used in construction fields. Tower crane is a mechanical device transporting construction supplies and heavy materials to places over 20~150M high from the ground for the period ranging from a short time of 2~3 months to two years after being installed in construction sites in vicinity of buildings or structures and is an important facility indispensable for construction sites. However, since use period after installation is short and professional technical ability of technicians working on-site about of tower crane is poor, systematic and quantitative safety management is not carried out As a part of researches on procedure of RBI(Risk Based Inspection) possible to apply to Knowledge Based System based on knowledge and experiences of experts as well as to tower cranes for solving these problems, quantitative RPN(Risk Priority Number) was applied to RPN utilizing technique of FMEA(Failure Mode and Effect Analyses). When general RBI 80/20 Rule was applied parts with high level of risks were found out as wire rope, hoist up/down safety device, reduction gear, and etc. However, since there are still many insufficient parts as risk analyses of tower crane were not established, it is necessary for experts with sufficient experiences and knowledge to supplement active RBI techniques and continuous researches on tower cranes by sharing and setting up data base of important information with this study as a starting point.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.4
• /
• pp.3-11
• /
• 2016

Recently, overseas plant orders of domestic enterprises are steadily increased, and the amount of orders in the first half of 2014 were 93% increased compared to the previous year. In addition, now which is the third quarter of 2015, overseas plant orders are already over 249.8 billion dollars so the interests of plant industry research has been increased. In the life cycle of the plant project, CM before the construction stage is to complement the uncertainties that are inherent in the early stages of the project, and from the viewpoint of supporting the rational decision-making, the importance of its role is on the rise. Among them, excavating and investing participation plan in the planning stage is an important work that has a large impact force to influence the success and failure of future project. However, the work has become a problem with frequent consultations due to decision-making, continuous modification, and inefficient repetitive tasks. Therefore, it is needed that work process should be changed to effectively accommodate. The purpose of this paper is to derive the major work items for excavating and investing participation plan in the planning stage of the plant project, and establish a standardized work process through the Delphi analysis. The result of this study is expected to be utilized for EPC companies in ensuring the technical competitiveness in planning on overseas markets, and improve the efficiency of work.

• Journal of the Microelectronics and Packaging Society
• /
• v.16 no.2
• /
• pp.43-50
• /
• 2009

Although thin PCBs(Printed Circuit Boards) have recently been required for high density interconnection, high electrical performance, and low manufacturing cost, the utilization of thin PCBs is severely limited by warpage and reliability issues. Warpage of the thin PCB leads to failure in solder-joints and chip. The $B^2it$(Buried Bump Interconnection Technology) for PCB has been developed to achieve a competitive manufacturing price. In this study, chip temperature, package warpage, chip stress and solder-joints stress characteristics of the PCB prepared with $B^2it$ process have been calculated using thermo-mechanical coupled analysis by the FEM(Finite Element Method). FEM computation was carried out with the variations in bump shapes and kinds of materials under 1.5W power of chip and constant convection heat transfer. The results show that chip temperature distribution reached more quickly steady-state status with PCB prepared with $B^2it$ process than PCB prepared with conventional via interconnection structure. Although $B^2it$ structures are effective on low package warpage and chip stress, with high strength bump materials arc disadvantage for low stress of solder-joints. Therefore, it is recommended that optimized bump shapes and materials in PCB design should be considered in terms of reliability characteristics in the packaging level.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.167-177
• /
• 1997

Oocyte donation program developed to reach the pregnancy in those patients suffering from premature ovarian failure or surgery induced menopause, particularly in their reproductive age. With technical advances and popularity of ART (assisted reproductive technology), the indication of oocyte donation program extended to low responders, and even to naturally menopaused patients that has led them quite successfully to getting in pregnancy. The purpose of this study was to evaluate which one is involved in the decline of fertility between the oocyte and uterine factor. One hundred five cycles of oocyte donation program were performed in 84 patients from Jan., 1993 to Dec., 1996. Oocytes were donated from healthy, young, fertile anonymous donors or relatives or infertile patients with supernumerary oocytes. The study population was divided into 3 groups according to the age of recipients. Group 1 was less than 35 years old, Group 2 was between 35 to 39 years old, and Group 3 was more than 39 years old. The results were as follows: The mean age of oocyte donor was $31.5{\pm}3.3$ (range; 25-36). The mean concentration of basal serum FSH and peak serum estradiol were not different among groups. The mean number of oocytes retrieved from donors, embryos transferred to recipients, and fertilization rate were not different among groups. The clinical pregnancy rate was 37.3% in Group 1, 31.6% in Group 2, and 31.6% in Group 3, respectively. The spontaneous abortion rate was 16.0% in Group 1, 16.7% in Group 2, and 16.7 in Group 3, respectively. The multiple pregnancy rate was 20.0% in Group 1, 16.7% in Group 2, 16,7% in Group 3, respectively, The implantation rate was 11.3% in Group 1, 10.3% in Group 2 and 10.0% in Group 3, respectively. All of the pregnancy outcomes were not different statistically among groups. In conclusion, endometrial receptivity does not seem to be impaired as age increases with transfer of good quality embryos and adequate endometrial preparation.

• Clean Technology
• /
• v.27 no.4
• /
• pp.297-305
• /
• 2021

In the domestic aluminum industry, the extrusion process is a major process accounting for more than 40% of the total production. However, most domestic aluminum extrusion companies produce aluminum using old equipment that is more than 30 years old. Extrusion press is when the equipment is not replaced before the wear and breakage of major parts occur, reducing productivity and increasing the defect rate compared to new equipment. The old extrusion press often loses part drawings, so it is difficult to repair them properly on-site and to remanufacture them due to the lack of technical skills for maintenance. Therefore, a systematic remanufacturing plan must be designed from dismantling the equipment. In this study, remanufacturing FMEA was devised to remanufacture old extrusion press. The risk priority was analyzed by considering the degree of damage to the recycled parts, the cycle due to breakage/damage during the extrusion process, and the value of recycling resources due to remanufacturing. To standardize the remanufacturing process, remanufactured FMEA was performed through part analysis according to the structural analysis of the extrusion press. In addition, remanufacturing priorities were selected for each part, while remanufacturing itself was studied for efficiency of resource circulation and product quality stabilization.

• Journal of the Korean GEO-environmental Society
• /
• v.19 no.12
• /
• pp.41-46
• /
• 2018

The wireless sensor network system has the advantage of confirming the behavior of the entire facility by improving the disadvantages of conventional monitoring system. As a result, it is widely proposed as safety diagnosis and measurement of structures, water management systems, and management systems for dam structures. However, there is a lack of research that can evaluate the condition of facilities such as safety at the same time as monitoring. In this study, it is proposed a wireless sensor network system which can evaluate the behavior characteristics of facilities and evaluate the safety status for improving the technical disadvantages on conventional monitoring system. The geotechnical risk factors for the reservoir dam facility were evaluated and the limit values for the risk factors causing the failure of the facility were set. In other words, the system was set up so that the risk factors can be measured and the limit status can be evaluated immediately for each factor. In this study, numerical analysis is carried out for seepage and slope stability analysis using the typical cross section for reservoir dams. The stress-porewater coupling finite difference numerical analysis is performed for establishing the limit displacement for reservoir dam structures. It is developed a system that can estimate the time to reach the critical value by regression analysis using the measured datas.