• Journal of Gastric Cancer
• /
• v.13 no.1
• /
• pp.26-33
• /
• 2013

Purpose: The aims are to: (i) display the multidimensional learning curve of totally laparoscopic distal gastrectomy, and (ii) verify the feasibility of totally laparoscopic distal gastrectomy after learning curve completion by comparing it with laparoscopy-assisted distal gastrectomy. Materials and Methods: From January 2005 to June 2012, 247 patients who underwent laparoscopy-assisted distal gastrectomy (n=136) and totally laparoscopic distal gastrectomy (n=111) for early gastric cancer were enrolled. Their clinicopathological characteristics and early surgical outcomes were analyzed. Analysis of the totally laparoscopic distal gastrectomy learning curve was conducted using the moving average method and the cumulative sum method on 180 patients who underwent totally laparoscopic distal gastrectomy. Results: Our study indicated that experience with 40 and 20 totally laparoscopic distal gastrectomy cases, is required in order to achieve optimum proficiency by two surgeons. There were no remarkable differences in the clinicopathological characteristics between laparoscopy-assisted distal gastrectomy and totally laparoscopic distal gastrectomy groups. The two groups were comparable in terms of open conversion, combined resection, morbidities, reoperation rate, hospital stay and time to first flatus (P>0.05). However, totally laparoscopic distal gastrectomy had a significantly shorter mean operation time than laparoscopy-assisted distal gastrectomy (P<0.01). We also found that intra-abdominal abscess and overall complication rates were significantly higher before the learning curve than after the learning curve (P<0.05). Conclusions: Experience with 20~40 cases of totally laparoscopic distal gastrectomy is required to complete the learning curve. The use of totally laparoscopic distal gastrectomy after learning curve completion is a feasible and timesaving method compared to laparoscopy-assisted distal gastrectomy.

• Transactions of Materials Processing
• /
• v.22 no.5
• /
• pp.269-274
• /
• 2013

Experiments and numerical simulations of the incremental upsetting test were carried out to investigate void closure behavior and mechanical characteristic of a 1.5wt%C ultra-high carbon steel. The experimental results showed that the voids become quickly smaller as the reduction ratio increases. The simulation results confirmed this behavior and indicated that the voids were completely closed at a reduction ratio of about 40~45% during incremental upsetting. After the completion of the incremental upsetting tests, the process of diffusion bonding was employed to heal the closed voids in the deformed specimens. To check the appropriate temperature for diffusion bonding, deformed specimens were kept at 800, 900, 1000 and $1100^{\circ}C$ for an hour. In order to investigate the effect of holding time for diffusion bonding at $1100^{\circ}C$, specimens were kept at 10, 20, 30, 40, 50 and 60minutes in the furnace. A distinction between closed and healed voids was clearly established using microstructural observations. In addition, subsequent tensile tests demonstrated that complete healing of a closed void was achieved for diffusion bonding temperatures in the range $900{\sim}1100^{\circ}C$ with a holding time larger than 1 hour.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.4
• /
• pp.1501-1518
• /
• 2016

This paper presents an effective management of VM (Virtual Machine) for heterogeneous cloud using Common Deployment Model (CDM) brokering mechanism. The effective utilization of VM is achieved by means of task scheduling with VM placement technique. The placements of VM for the physical machine are analyzed with respect to execution time of the task. The idle time of the VMis utilized productively in order to improve the performance. The VMs are also scheduled to maintain the state of the current VM after the task completion. CDM based algorithm maintains two directories namely Active Directory (AD) and Passive Directory (PD). These directories maintain VM with proper configuration mapping of the physical machines to perform two operations namely VM migration and VM roll back. VM migration operation is performed from AD to PD whereas VM roll back operation is performed from PD to AD. The main objectives of the proposed algorithm is to manage the VM's idle time effectively and to maximize the utilization of resources at the data center. The VM placement and VM scheduling algorithms are analyzed in various dimensions of the cloud and the results are compared with iCanCloud model.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.34 no.4
• /
• pp.82-88
• /
• 2011

A typical job sequencing problem is studied in this research to improve productivities in manufacturing companies. The problem consists of two-stage parts and assembly processes. Two parts are provided independently each other and then two sequential assembly processes are followed. A new heuristic is developed to solve the new type of sequencing problem. Initial solution is developed in the first stage and then the initial solution is improved in the second stage. In the first stage, a longer part manufacturing time for each job is selected between two, and then a sequence is determined by descending order of the times. This initial sequence is compared with Johnson's sequence obtained from 2-machine assembly times. Any mismatches are tried to switch as one possible alternative and completion time is calculated to determine whether to accept the new sequence or not to replace the current sequence. Searching process stops if no more improvement can be made.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.28 no.2
• /
• pp.7-16
• /
• 2022

Purpose: This study aimed to present an analysis model evaluating evacuation performance considering patient types and procedural evacuation in the medical facility. The user group of the medical facility, including users challenged in evacuation behavior, entails the risk of many casualties. Therefore, it is necessary to plan an evacuation procedure that considers the evacuation characteristics of users. Methods: Through the review of precedent studies, the evacuation procedure of the medical facility, the classification of patient types, and the evacuation procedure was set as conditions and variables for the analysis. The result caused by a variety of conditions and variables were explored. Results: 1) The total evacuation completion time and congestion time were shortened at the procedural evacuation. Moreover, it derived many users from evacuating at the initial phase. 2) The proposed model can provide a basis for proposing a space planning direction that considers the possibility of not carrying out the evacuation plan. 3) It supports safe evacuation by identifying variables that reduce overcrowding by comparing the congestion time of overcrowded spaces. 4) The analysis model can identify the overcrowded space through the evacuation route and suggest the basis for architectural improvements that reduce overcrowding. Implications: The study results can be used to analyze the performance of evacuation procedures and support the establishment of evacuation procedures and building plans for safe evacuation for medical facilities.

• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.270-286
• /
• 2017

Managing waiting experience is critical for providing service because waiting is an inevitable experience. We explored the factors which influence the waiting experience of the customers and the experience they face, in order to find out the meaning of waiting experience of the customer. As a result, we investigated a holistic sequence divided into four stages. When the customers wait for the service, perceived time would be increased by Zeigarnik effect. How long the customers feel when waiting is largely affected by a gap between waiting time and the perceived time, rather than the perceived time itself. Furthermore, the customers showed a tendency to have hard time immersing in the media due to considering others. Additionally, we could find that waiting time after giving an order is relatively more important than the waiting time before the order. Based on the results, the service provider should convey a feeling of completion by fitting the end point of the media to the point when the customer receives the service. In addition, high predictability needs to be offered for the customers in order to predict the exact waiting time. Finally, the customers should feel as if they take the initiative during waiting time.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.59.3-59.3
• /
• 2015

National Youth Space Center will complete installation of the NYSC 1m Telescope in this year. Before completion of the telescope, we present the software design of JTCS, and the preliminary result of tracking performance by JTCS and mount of the telescope. JTCS currently uses commercial software of the Sky X, for the real-time coordinates of various objects, such as asteroids, comets, and even satellites. In order to guarantee flexibility in CCD detectors, the MaxIm DL software was adopted and JTCS provides auto-guiding and scheduled image-taking with MaxIm DL. We are now stabilizing the telescope mount and JTCS with long-exposure tests, and gathering the preliminary data of tracking performance.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2000.11a
• /
• pp.69-70
• /
• 2000

The completion of sequencing human genome would motivate us to map millions of human cDNAs onto the unique ruler "genome sequence", in order to identify the exact address of each cDNA together with its exons, its promoter region, and its alternative splicing patterns. The expression patterns of some cDNAs could therefore be associated with these precise gene addresses, which further accelerate studies on mining correlations between motifs of promoters and expressions of genes in tissues. Towards the realization of this goal, we have developed a time-and-space efficient software named SQUALL that is able to map one cDNA sequence of length a few thousand onto a long genome sequence of length thirty million in a couple of minutes on average. Using SQUALL, we have mapped twenty thousand of our Bodymap (http://bodymap.ims.u-tokyo.ac.jp) cDNAs onto the genome sequences of Chr.21st and 22nd. In this talk, I will report the status of this ongoing project.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.4
• /
• pp.219-226
• /
• 2012

Recently real-estate investment business is standing out as a new plan for creation of source of income. In this paper, we suggested appropriate real-estate investment strategy through the reconstruct case study of existing one-storied building. That is, we showed the efficient process of decision and propel to reconstruct and the key points for lease business and post management after building completion. Also, we analyzed the rate of return of commercial building investment in order to find its optimum dealing time. Therefore the results of this paper are expected to be a help to old ages and persons laying plans for a similar business.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.854-859
• /
• 2008

This study describes the aging behavior of soils and its mechanism, which have been reported in the literatures mainly by Mitchell(1986) and Schmertmann(1991). It could be known that aging of soils has both positive and negative effects on mechanical properties of soils. In order to show aging effects on dam behavior, a parametric study was carried out based considering the presence of a weak area within clay core zone of the fill dam. From the comparison of results obtained from numerical analysis and filed investigation, age-softening phenomena occurred within core zone during about 30 years after its completion.