• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.6 s.348
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• pp.1-8
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• 2006

In the asynchrous OFCDM(Orthogonal Frequency and Code Division Multiplexing) system, a three-step cell search algorithm is performed for the initial synchronization in the following three steps: OFCDM symbol timing, i.e., Fast Fourier Transform(FFT) window timing is estimated employing guard interval (GI) correlation in the first step, then the frame timing and CSSC (Cell Specific Scrambling Code) group is detected by taking the correlation of the CPICH(Common Pilot Channel) based on the property yeilded by shifting the CSSC phase in the frequency domain. Finally, the CSSC phase within the group is identified in the third step. This paper proposes a modification code(PCSSCG:Patial Cell Specific Scrambling Code Group) of the conventional CPICH based cell search algorithm in the second step which offers MS(Mobile Station) complexity reductions with the nearly same performance. The proposed method is to be compared and verified through the computer simulation.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.84.1-84.1
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• 2013

We present a python-based data reduction pipeline for the Immersion GRating INfrared Spectrograph (IGRINS). IGRINS covers the complete H- and K-bands in a single exposure with a spectral resolving power of greater than 40,000. IGRINS is designed to be compatible with telescopes of diameters ranging from 2.7-m (the Harlan J. Smith telescope at McDonald Observatory) to 8-10m. Commissioning and initial operation will be on the 2.7-m telescope from late 2013. The pipeline package is a part of the IGRINS software and designed to be compatible with other package that maneuvers the spectrograph during the observation. This package provides high-quality spectra with minimal human intervention and the processes of order extraction, distortion correction, and wavelength calibration can be automatically carried out using the predefined functions (e.g. echellogram mapping and 2D transform). Since the IGRINS is a prototype of the Giant Magellan Telescope Near-Infrared Spectrometer (GMTNIRS), this pipeline will be extended to the GMTNIRS software.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.E
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• pp.17-28
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• 1999

Gas-liquid contact tests above a perforated-plate were conducted with air and water at flooding gas-flow conditions in order to study two-phase flow characteristics in a limestone-gypsum SO2 absorber. Gas layers were in the form of air pockets and confined to the limited areas around each duct pipe, while the remaining tary area were in the wet condition. The liquid above the tray was always in the flooded and even fluidized conditions at gas flows over the range studied, although vigorous bubbly or churn-turbulent two-phase regime was only observed in the immediate vicinity of the gas hole exit at low gas loads. The froth zone was extremely active to provide intimate contact between gas and liquid so that the necessary mass transfer operation can take place, which is the primary purpose of high-performance SO2 absorbers. Howefer, the absorber $\Delta$P was 250mmH2O for the initial water level at 150mm, which is an important issue to be resolved for economical operation of the SO2 absorber. It was seen in the liquid level-and gas flow-transient tests that changes in the absorber liquid inventory were much more pronounced for intimate gas-liquid contact than changes in the gas flow. Based on the 4- and 8-duct pipe test results, grouping the duct pipes near the center of the test tray seemed to promote better recirulation of liquid from gas-liquid contact zone back to the reaction tank so that the absorbed SO2 can be neutralized.

• Korean Journal of Materials Research
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• v.24 no.6
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• pp.310-318
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• 2014

In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and N-Hydroxysuccinamide (EDC-NHS). The initial average pore size of the scaffold ranged from 300 to $700{\mu}m$, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1 pre-osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCP-BG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater (geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).

• Journal of Korean Neurosurgical Society
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• v.52 no.3
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• pp.221-227
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• 2012

Objective : Spinal cord hemangioblastomas are rare tumors. Despite their benign, slow-growing nature, they can cause severe neurological consequences. The purpose of this study was to evaluate variable factors, including clinical features, tumor findings, the extent of resection, and its recurrence or progression, which determine postoperative functional outcomes. Methods : This study included sixteen patients at our institute who underwent microsurgical resection for sporadic spinal intramedullary hemangioblastomas and spinal intramedullary hemangioblastomas associated with von Hippel-Lindau (VHL) disease, between June 2003 and March 2012. Results : A total of 30 operations were performed. Total resection (TR) of the tumor was achieved in 10 patients, and subtotal resection (STR) was achieved in 6. Postoperatively, the initial presenting symptoms were improved in 18.7% of the patients and were unchanged in 56.3%, but 25% were worse. Stable postoperative neurological functions were found in 83% of patients with preoperative McCormick grade I, and TR was achieved in 75% of these patients. In the STR group, poorer neurological status was observed in one patient, despite multiple operations. There were no poorer outcomes in the four cases of VHL disease. Various factors were analyzed, but only a correlation between the pre- and postoperative neurological status was verified in the TR-group patients. Conclusion : Preoperative focal neurological impairment and meticulous microsurgical manipulation may be predictors of favorable outcomes for solitary hemangioblastomas. In addition, the preservation of function is more important than the extent of resection in VHL disease.

• Archives of Plastic Surgery
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• v.45 no.6
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• pp.534-541
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• 2018

Background Nipple-areolar complex (NAC) reconstruction following curative mastectomy is traditionally performed as a second-stage procedure several months after initial breast reconstruction. The recent literature has documented the increasing popularity of immediate nipple reconstruction carried out simultaneously during autologous reconstruction. The aim of this study was to evaluate the surgical outcomes and patient satisfaction with immediate breast and nipple reconstruction performed in a single stage after skin-sparing mastectomy. Methods All patients who underwent a skin-sparing mastectomy with immediate latissimus dorsi flap breast and NAC reconstruction as a single-stage procedure from 2007 to 2015 were included. Patient demographics, oncologic details, and surgical outcomes were recorded. The BREAST-Q questionnaire was administered to patients to assess the impact and effectiveness of this reconstructive strategy. Results During the study period, 34 breast and NAC reconstructions in 29 patients were performed at Cork University Hospital. The majority of our patient cohort were non-smokers (93.1%) and did not receive adjuvant radiotherapy. Postoperative complications were infrequent, with no cases of partial necrosis or complete loss of the nipple. The response rate to the BREAST-Q was 62% (n=18). Patients reported high levels of satisfaction with the reconstructed breast ($62{\pm}4$), nipple reconstruction ($61{\pm}4.8$), overall outcome ($74.3{\pm}5$), and psychosocial well-being ($77.7{\pm}3.2$). Conclusions Skin-sparing mastectomy with immediate nipple reconstruction during autologous latissimus dorsi reconstruction was demonstrated to be a safe and aesthetically reliable procedure in our cohort, yielding high levels of psychological and physical well-being. A single-stage procedure promotes psychosocial well-being involving issues that are intrinsically linked with breast cancer surgery.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.572-578
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• 2007

Two stroke low speed diesel engines are widely used for marine propulsion or as power plant prime mover. These engines have many merits which includes higher thermal efficiency, mobility and durability. Yet various annoying vibrations occur sometimes in ships or at the plant itself. Of these vibrations, torsional vibration is very important and dictates a careful investigation during the engme's initial design stage for safe operation. With the rule and limit on torsional vibration in place, shaft strength fatigue due to torsional vibration however demands further analysis which possibly can be incorporated in the classification societies' rule and limit. In addition, the shaft's torsional vibration stresses can be calculated equivalently from accumulated fatigue cycles number due to transient torsional vibration in time domain. In this paper, authors suggest a new estimation method combined with Palmgren-Miner equation. A 6S70MC-C ($25,320ps{\times}91rpm$) engine for ship propulsion was selected as a case study. Angular velocity was measured, instead of shaft's strain, for simplified measurement and it was converted to torsional vibration stress for accumulated fatigue cycle numbers in shafting life time. Likewise, the accumulated fatigue calculation was compared with shaft fatigue strength limit. This new method can be further realized and confirmed in ship with two stroke low speed diesel engine.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.318-322
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• 2006

The intracellular invertase gene of alkalophilic and thermophilic Bacillus sp. TA-11 which was isolated from compost was cloned and expressed in E. coil HB101 using pUC19 as a vector. The invertase of the recombinant E. coli (pYC 17) was maximally produced when it was incubated at 37$^{\circ}C$ for 9 h in a SY medium containing 0.25% sucrose, 0.5% yeast extract, 0.1% each of $K_2HPO_4$ and $KH_2PO_4$, with an initial pH of 8.0. The final enzyme activity under the above condition was 47.7 U per ml of cell-free extract.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.1
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• pp.33-37
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• 2009

Anti-inflammatory factor(AIF) is a water soluble extract of three herbs, Panax notoginseng(Burk.) F. H. Chen, Rehmannia glutinosa Libosch and Eleutherococcus senticosus. The present study aimed to investigate the safety and efficacy of herb extracts, AIF, on Korean knee osteoarthritis patients for six weeks. Fifty seven patients with knee osteoarthritis, ranging from 43 to 73 years of age, who fulfilled the "American College of Rheumatology"(ACR) classification of idiopathic osteoarthritis of knee and radiographic criteria were randomly selected and enrolled for the study. After initial screening and resting period, two capsules each of AIF(Each capsule contains; 400 mg) and similar identical placebo were administered twice a day to both groups. Pain intensity at second, fourth, and sixth weeks of study as well as one week after discontinuation of drugs was assessed by using 100 mm visual analogue scale(VAS). Changes in the Korean version of the Western Ontario and McMaster Universities(K-WOMAC) index score were compared at the initiation and completion of the study. VAS assessed by patients were significantly reduced(at visit 2; $54.64{\pm}14.72$, at visit 4, $37.32{\pm}16.58$, p<0.001) after AIF administration. Results showed an improvement in the physical function of K-WOMAC scale which was significantly higher(p=0.013) in AIF than placebo group, and decreases of total K-WOMAC score were also significantly higher(p=0.030) in AIF groups than placebo group. No serious adverse effect was observed, and there was no difference in incidence of adverse effect between AIF and placebo groups. In this population of Korean patients with knee osteoarthritis, AIF was found to be safe, tolerable and effective for symptomatic improvement of pain and physical function.

• Journal of Periodontal and Implant Science
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• v.44 no.1
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• pp.39-47
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• 2014

Purpose: Peri-implantitis, a clinical term describing the inflammatory process that affects the soft and hard tissues around an osseointegrated implant, may lead to peri-implant pocket formation and loss of supporting bone. However, this imprecise definition has resulted in a wide variation of the reported prevalence; ${\geq}10%$ of implants and 20% of patients over a 5- to 10-year period after implantation has been reported. The individual reporting of bone loss, bleeding on probing, pocket probing depth and inconsistent recording of results has led to this variation in the prevalence. Thus, a specific definition of peri-implantitis is needed. This paper describes the vast variation existing in the definition of peri-implantitis and suggests a logical way to record the degree and prevalence of the condition. The evaluation of bone loss must be made within the concept of natural physiological bony remodelling according to the initial peri-implant hard and soft tissue damage and actual definitive load of the implant. Therefore, the reason for bone loss must be determined as either a result of the individual osseous remodelling process or a response to infection. Methods: The most current Papers and Consensus of Opinion describing peri-implantitis are presented to illustrate the dilemma that periodontologists and implant surgeons are faced with when diagnosing the degree of the disease process and the necessary treatment regime that will be required. Results: The treatment of peri-implantitis should be determined by its severity. A case of advanced peri-implantitis is at risk of extreme implant exposure that results in a loss of soft tissue morphology and keratinized gingival tissue. Conclusions: Loss of bone at the implant surface may lead to loss of bone at any adjacent natural teeth or implants. Thus, if early detection of peri-implantitis has not occurred and the disease process progresses to advanced peri-implantitis, the compromised hard and soft tissues will require extensive, skill-sensitive regenerative procedures, including implantotomy, established periodontal regenerative techniques and alternative osteotomy sites.