434 research outputs found
An Agent Based Market Design Methodology for Combinatorial Auctions
Auction mechanisms have attracted a great deal of interest and have been used in diverse e-marketplaces. In particular, combinatorial auctions have the potential to play an important role in electronic transactions. Therefore, diverse combinatorial auction market types have been proposed to satisfy market needs. These combinatorial auction types have diverse market characteristics, which require an effective market design approach. This study proposes a comprehensive and systematic market design methodology for combinatorial auctions based on three phases: market architecture design, auction rule design, and winner determination design. A market architecture design is for designing market architecture types by Backward Chain Reasoning. Auction rules design is to design transaction rules for auctions. The specific auction process type is identified by the Backward Chain Reasoning process. Winner determination design is about determining the decision model for selecting optimal bids and auctioneers. Optimization models are identified by Forward Chain Reasoning. Also, we propose an agent based combinatorial auction market design system using Backward and Forward Chain Reasoning. Then we illustrate a design process for the general n-bilateral combinatorial auction market. This study serves as a guideline for practical implementation of combinatorial auction markets design.Combinatorial Auction, Market Design Methodology, Market Architecture Design, Auction Rule Design, Winner Determination Design, Agent-Based System
Abducens nerve palsy as a postoperative complication of minimally invasive thoracic spine surgery: a case report
Primary repair of symptomatic neonates with tetralogy of Fallot with or without pulmonary atresia
Recently, surgical outcomes of repair of tetralogy of Fallot (TOF) have improved. For patients with TOF older than 3 months, primary repair has been advocated regardless of symptoms. However, a surgical approach to symptomatic TOF in neonates or very young infants remains elusive. Traditionally, there have been two surgical options for these patients: primary repair versus an initial aortopulmonary shunt followed by repair. Early primary repair provides several advantages, including avoidance of shunt-related complications, early relief of hypoxia, promotion of normal lung development, avoidance of ventricular hypertrophy and fibrosis, and psychological comfort to the family. Because of advances in cardiopulmonary bypass techniques and accumulated experience in neonatal cardiac surgery, primary repair in neonates with TOF has been performed with excellent early outcomes (early mortality<5%), which may be superior to the outcomes of aortopulmonary shunting. A remaining question regarding surgical options is whether shunts can preserve the pulmonary valve annulus for TOF neonates with pulmonary stenosis. Symptomatic neonates and older infants have different anatomies of right ventricular outflow tract (RVOT) obstructions, which in neonates are nearly always caused by a hypoplastic pulmonary valve annulus instead of infundibular obstruction. Therefore, a shunt is less likely to preserve the pulmonary valve annulus than is primary repair. Primary repair of TOF can be performed safely in most symptomatic neonates. Patients who have had primary repair should be closely followed up to evaluate the RVOT pathology and right ventricular function
An End-to-End Tool for Developing CPSs from Design to Implementation
For a Cyber-Physical System (CPS), the real-time execution must be guaranteed at the design time for the safe and reliable interaction between a Cyber and a Physical System. Thus, simulation method is widely used to verify and validate the behavior of a CPS, in the development process. Commercial tools of today, however, only mimic the functional behavior of the system, not the temporal behavior. Moreover, when the simulation target system is changed, developers have to reconfigure all settings to simulate properly. To overcome this limitation, we introduce our End-to-End Development Tool that can support the functional and temporal co-validation and smooth migration for the change of the simulation target system.OAIID:RECH_ACHV_DSTSH_NO:A201617646RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A077084CITE_RATE:FILENAME:V2CPS_final.pdfDEPT_NM:컴퓨터공학부EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/8cf7890c-46ec-4551-9c3e-2715774d7f34/linkCONFIRM:
Transition from Pemphigus Foliaceus to Pemphigus Vulgaris: Case Report with Literature Review
The transition between the main subtypes of pemphigus, pemphigus vulgaris (PV), and pemphigus foliaceus (PF) has rarely been reported. Moreover, the development of PV in a patient with PF is much more unusual than that of PF in a patient with PV. We report a 48-year-old man who presented with cutaneous lesions showing the typical clinical and histological features of PF. Five years later, his skin lesions became extensive and he developed oral erosions. His condition did not respond well to steroids and azathioprine. Histological examination of a vesicle disclosed suprabasal acantholysis in contrast to the subcorneal acantholysis discovered upon initial histological evaluation. Indirect immunofluorescence revealed IgG antikeratinocyte cell surface antibodies at a titer of 1:640. The titer was 1:160 at initial diagnosis. Upon immunoblotting, the patient's serum reacted with 130 kiloDalton (kDa) and 160 kDa proteins, suggesting desmoglein (Dsg) 3 and 1, respectively. We herein report an unusual case of PV that developed from PF during the disease's flare-up
STATIC AND DYNAMIC CHARACTERISTICS OF AIR FOIL THRUST BEARING CONSIDERING TILTING PAD CONDITION
ABSTRACT The thrust pad of the rotor is used to sustain the axial force generated due to the pressure difference between the compressor and turbine sides of turbomachinery such as the gas turbines and turbochargers. Furthermore, this thrust pad has a role to maintain and determines the attitude of the rotor. In a real system, it also helps reinforce the stiffness and damping of the journal bearing. This study was performed for the purpose of analyzing the characteristics of the air foil thrust bearing. The model for the air foil thrust bearing used in this study is composed of two parts: one is an inclined plane, which plays a role to increase the load carrying capacity using the physical wedge effect, and the other is a flat plane. This study mainly consists of three parts. First, the static characteristics were obtained over the region of the thin air film using the finite difference method (FDM) and the bump foil characteristics using the finite element method (FEM). Second, the analysis of the dynamic characteristics was conducted by perturbation method. For more exact calculation, the rarefaction gas coefficients perturbed about the pressure and film thickness were taken into consideration. At last, the static and dynamic characteristics of the tilting condition of the thrust pad were obtained. Furthermore, the load carrying capacity and torque were calculated for both tilting and not-tilting conditions. From this study, several results were presented: 1) the stiffness and damping of the bump foil under the condition of the various bump parameters, 2) the load carrying capacity and bearing torque at the tilting state, 3) the bearing performance under various bearing parameters, 4) the effects considering the rarefaction gas coefficients
The Influence of Pain Sensitivity on the Symptom Severity in Patients with Lumbar Spinal Stenosis
Background: The symptom severity of back pain/leg pain is not correlated with the severity of degenerative changes and canal stenosis in lumbar stenosis. Considering the individual pain sensitivity might play an important role in pain perception, this discordance between the radiologic findings and clinical symptoms in degenerative lumbar stenosis might originate from the individual difference of pain sensitivity for back pain and/or leg pain.Objective: To determine the relationship among the clinical symptoms, radiologic findings, and the individual pain sensitivity in the patients with degenerative lumbar spinal stenosis.Study Design: Retrospective analysis of prospectively collected data.Setting: A spine center in the department of orthopedic surgery.Methods: In 94 patients who had chronic back pain and/or leg pain caused by degenerative lumbar spinal stenosis, a medical history, a physical examination, and completion of a series of questionnaires, including pain sensitivity questionnaire (PSQ) [total PSQ and PSQ-minor], Oswestry Disability Index (ODI), Visual Analog Pain Scale (VAS) for back pain, and Short Form-36 (SF-36) were recorded on the first visit. Radiologic analysis was performed using the MRI findings. The grading of canal stenosis was based on the method by Schizas, and the degree of disc degeneration was graded from T2-weighted images with the Pfirrmann classification. The correlations among variables were statistically analyzed.Results: Total PSQ and PSQ-minor were not dependent on the grade of canal stenosis after gender adjustment. VAS for leg pain and back pain was highly associated with the total PSQ and the PSQ-minor. Total PSQ and PSQ-minor were also significantly associated with ODI. Among SF-36 scales, the PSQ minor had significant correlations with SF-36 such as bodily pain (BP), Role-emotional (RE), and Mental Component Summary (MCS) after control of confounding variables such as body mass index (BMI), age, and the grade of canal stenosis/disc degeneration. Total PSQ was significantly associated with the SF-36 RP, BP, and RE. Furthermore, after adjustment for gender and pain sensitivity, there was no significant association between the grade of canal stenosis and VAS for back pain/leg pain and ODI, and no correlation was found between the grade of disc degeneration and VAS for back pain/leg pain and ODI, either.Limitations: The multiple lesions of canal stenosis and/or disc degeneration and the grade of facet degeneration were not considered as a variable.Conclusion: The current study suggests that the pain sensitivity could be a determining factor for symptom severity in the degenerative spinal disease.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000004226/3SEQ:3PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:YEMP_ID:A076317DEPT_CD:801CITE_RATE:10.722FILENAME:E046T_PainPhysician_Kim_The Influence of Pain Sensitivity on the Symptom Severity.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YCONFIRM:
Benign Metastasizing Leiomyoma with Multiple Lymph Node Metastasis: A Case Report
This is a case report about benign metastasizing leiomyoma with multiple lymph node metastasis. A 34-year-old woman received an abdominal myomectomy for a suspicious leiomyoma. On the pathology report, atypical leiomyoma was suspected. Due to the suspicion of multiple lymph node metastasis on pelvis computed tomography (CT) 1 year after the operation, she was transferred to the Samsung Medical Center on October, 2009 for further work up. According to original slide review, it was determined to be a benign leiomyoma with a mitotic count <5/10 high-power fields, little cytological atypia and no tumor cell necrosis. Additional immunostaining was done. Multiple lymph node metastasis and a small lung nodule were identified on positron emission tomogarphy-CT and chest CT. Extensive debulking surgery and diagnostic video-assisted thoracoscopic surgery (VATS) wedge resection were subsequently done. Metastatic lesions were reported to have a histology similar to that of the original mass. VATS right upper lobectomy with mediastinal lymph node dissection was performed because of the pathology result of VATS (adenocarcinoma). She started taking an aromatase inhibitor (Letrozole®) and there was no evidence of recurrence of disease on an imaging study and no post-operative complications until recently
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