• Economic and Environmental Geology
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• v.28 no.6
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• pp.599-612
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• 1995

Some REE ore deposits are located in the middle part the of Korean peninsula. Geotectonically, the REE ore deposits situated on the Kyemyeongsan Formation of northern margin of the Okcheon geosynclinal belt and in the transitional zone between Kyeonggi massif and the Okcheon belt, with a deep-seated fracture separating the two tectonic units. The Kyemyeongsan Formation are different in lithology and metamorphic grade from the Gyeonggi massif and the Okcheon super group. The sequence of Kyemyeongsan Formation is dominantly composed of acidic metavolcanic and volcaniclastic rocks associated with alkaline igneous rocks which are related to volcano-plutonism. The REE ore deposits contain mainly Ce-La, Ta-Nb, Y, Y-Nd and Nd-Th group minerals. More than 15 RE and REE minerals have been found in the deposits, such as allanite, fergusonite, thorite bestnaesite, euxenite, polyclase, monazite, columbite, (Nb)-rutile, okanoganite, sphene, zircon, illmenite and some other unknown minerals. According to the characteristics of the mineral association, the REE ore deposits may be divided into 4 ore types; Zircon-REE, allanite-REE, feldspar-REE and fluorite-REE type. The Sm-Nd isochron age of the REE ore is 330 Ma, and the Sm-Nd model age is 1.11 Ga with ${\varepsilon}_{Nd(t)}$ being - 2.9. This data suggest that the REE ore deposit was formed in the early Carboniferous, and the ore-forming material came from the mantle. The REE ores show distinct light REE enrichment with strong negative Eu anomaly. The REE patterns of schistose rocks from Kyemyeongsan Formation are similar to felsic volcanics from rifts or back arc basins in or near continental crust. The genesis of the REE ore deposit is quite complicated. Different geologic processes are displayed in the studied area; sedimentation, volcanic activity, metamorphism and hydrothermal replacement. Alkali granite has suffered extensive post-magmatic metasomatism of a high temperature to produce alkali metasomatites. Geochemical charateristics show that metasomatism of alkaline fluid was probably the dominant ore-forming process in Chungju district.

• Korean Journal of Head & Neck Oncology
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• v.16 no.1
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• pp.52-57
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• 2000

Purpose: The purpose of the study was to evaluate the sensitivity, specificity and accuracy between the FNAC and intraopevative frozen biopsy based upon the Final histologic diagnosis. Method: Authors studied 232 cases of thyroid nodule operated at Department of Surgery, College of Medicine, Chosun University, from January 1992 to December 1998. The medical records of these patients were studied retrospectively. The cytology of FNAC and the frozen section was compared to the final histologic diagnosis. 232 cases were analysed in regard to correlation of FNAC diagnosis and Intraoperative frozen section with final pathology, preoperative thyroid scan, thyroid function test, ultrasonography, final histopathology of the specimens, and surgical operation methods. 174 cases who underwent FNAC for diagnosis before operation, and Intraoperative frozen-section biopsy were classified according to whether the clinical diagnosis was benign, suspicious or malignant and evaluated the specificity sensitivity and accuracy. Result: Comparing with final histopathology, FNAC as a diagnostic test for thyroid nodules demonstrated an accuracy of 81.3%, a sensitivity of 87.5%, a specificity 86.5% with a false positivity of 2.9%, false negativity of 4.3%, respectively. and Intra-operative frozen section demonstrated an accuracy of 86.8%, a sensitivity of 87.5%, a specificity 92.1%. In the benign lesion, there was no difference in accuracy between FNAC(95.6%) and frozen section(95.1%) but, in the suspicious malignant lesion, frozen section(46.2%) was superior to FNAC(32.0%), and in the malignant disease, FNAC(97.1%) was superior to frozen section(92.3%). Conclusion: Intraoperative frozen section biopsy is useful in patients undergoing surgery for a thyroid nodule with a 'suspicious' malignant lesion and could reduce inadequate extensive excision without missing malignancy and second operation and help to determine the resection margin. It adds no information in patients with a diagnosis of malignancy following FNAC assessment and is of limited use in those in whom a benign lesion is diagnosed.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.581-588
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• 2008

Purpose: It is generally accepted that anatomical structures of the soft tissue in Asian faces are quite different from those in Caucasian. It is presumed that these differences are due to collagen rich thick dermis and durable superficial musculo-apponeurotic system (SMAS) in Asian. We classified the aging lower eyelids and reviewed the operative procedures according to the types of aging lower eyelids in Asian. Methods: We compared preoperative and postoperative photos of 117 patients over 30 years of age, who underwent lower blepharoplasty at the Kyunghee Medical Center from January 2001 to April 2006. We classified the patients based on the degree of skin laxity, presence of nasojugal groove and malar bag, the extent of aging process. We also reviewed the operative procedures according to each type of classification. Results: We classified our patients into four types as following. Type I patients showed minimal skin-muscle excess confined to lower eyelids regardless of the facial line. For these patients, we performed only transcutaneous or transconjunctival blepharoplasty. In type II patients, nasojugal grooves were shown and skin- muscle laxity was limited to the medial side of imaginary vertical line at lateral margin of pupil. In these cases, we performed free fat graft or fat repositioning on nasojugal groove or fat removal and septal duplication confined to medial side. Type III patients displayed more advanced medial bulging and remarkable laxity over the lateral side, the same operation methods as those of type II were applied at the lateral side of the line. Type IV patients demonstrated extensive midfacial aging changes including malar bags and underwent superficial subciliary cheek lift. Conclusion: The lower eyelid aging of Asian is different from those of Caucasian. We think that our classification is useful in selection of appropriate operative procedure to address specific problems for Asian patients.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.1-6
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• 2009

Purpose: This study presents a classification of pure medial and inferior blow-out fracture, and confirms the relationship between the types of fractures, postoperative complications and operative methods. Methods: Sixty patients were treated by transnasal endoscopic reduction with $Medpor^{(R)}$ implantation through subciliary incision and foley catheter insertion into maxillary sinus was done if there was extensive orbital floor fracture. Fractures were classified by number of coronal sections from posterior margin of fossa for lacrimal sac to orbital apex in CT. Type I is defined when the medial wall fracture is over 50% and inferior wall fracture below 50%. Type II, when below 50% medial wall fracture and over 50% floor fracture were present. If there were both over 50%, it was classified as Type III and both below 50% for Type IV. Extreme fracture involving orbital buttress was Type V and postoperative findings in all patients were examined. Results: Type I and V were most common and preoperative findings were more likely to present according to extent of inferior fracture. Diplopia remained in 2 cases after additional insertion of foley catheter, but enophthalmos over 2 mm were presented in 3 cases and diplopia in 3 cases were observed who were not treated with foley catheter. Conclusion: Postoperative complications were increased according to extent of fracture, especially buttress involvement. Additional insertion of foley catheter proved its effectiveness in decreasing postoperative complications.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3045-3050
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• 2013

Purpose: Hepatic resection is arguably the preferred treatment for huge hepatocellular carcinoma (H-HCC). Estimating the remnant liver volume is therefore essential. This study aimed to evaluate the feasibility of using computer-assisted volumetric analysis for this purpose. Methods: The study involved 40 patients with H-HCC. Laboratory examinations were conducted, and a contrast CT-scan revealed that 30 cases out of the participating 40 had single-lesion tumors. The remaining 10 had less than three satellite tumors. With the consensus of the team, two physicians conducted computer-assisted 3D segmentation of the liver, tumor, and vessels in each case. Volume was automatically computed from each segmented/labeled anatomical field. To estimate the resection volume, virtual lobectomy was applied to the main tumor. A margin greater than 1 cm was applied to the satellite tumors. Resectability was predicted by computing a ratio of functional liver resection (R) as (Vresected-Vtumor)/(Vtotal-Vtumor) x 100%, applying a threshold of 50% and 60% for cirrhotic and non-cirrhotic cases, respectively. This estimation was then compared with surgical findings. Results: Out of the 22 patients who had undergone hepatectomies, only one had an R that exceeded the threshold. Among the remaining 18 patients with non-resectable H-HCC, 12 had Rs that exceeded the specified ratio and the remaining 6 had Rs that were < 50%. Four of the patients who had Rs less than 50% underwent incomplete surgery due to operative findings of more extensive satellite tumors, vascular invasion, or metastasis. The other two cases did not undergo surgery because of the high risk involved in removing the tumor. Overall, the ratio of functional liver resection for estimating resectability correlated well with the other surgical findings. Conclusion: Efficient pre-operative resectability assessment of H-HCC using computer-assisted volumetric analysis is feasible.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.169-173
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• 2008

Purpose: Sacrococcygeal pilonidal sinus is a chronic inflammatory disease that mostly affects young people, which warrants surgical intervention. Although many surgical methods have been suggested, an optimal surgical method remains controversial because of high recurrence rates and postoperative complications. The objective of this study is to evaluate the results of wide excision and coverage with fasciocutaneous advancement flap for the treatment of sacrococcygeal pilonidal sinus, and to assess the usefulness of this method Methods: From May 1995 to October 2006, the authors treated 19 patients with the use of coverage with fasciocutaneous flap after wide excision. The results were evaluated regarding recurrence rates, complications, and the change in sensitivity of the gluteal region after surgery. The follow-up period was 7 to 142 months (mean, 76 months). All patients were male. Results: Postoperative complications were wound infection at the suction drain insertion site and skin necrosis around the suture margin in one case, respectively. During the follow up period, only one recurrence (5.3%) was seen in fifth postoperative month, which was successfully treated by the same operative procedure. There was no other complications such as seroma, hematoma, wound dehiscence and flap loss. Extensive scarring and anatomic distortion did not occur in the reconstructed area. In addition, sensitivity of the gluteal region did not diminish. The aesthetic results were satisfactory for all patients as well. Conclusion: The authors advocate that fasciocutaneous flap closure be a good alternative method to cover defects after the excision of sacrococcygeal pilonidal sinus.

• Economic and Environmental Geology
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• v.25 no.1
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• pp.51-60
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• 1992

The pluton rocks in Kwangyang-Seungju area consist of two mica granite, hornblende diorite, Rimunri quartz diorite, grnodiorite porphyry and granophyre. The analysis of the geochronological data by the methods of K-Ar for the hornblende from Rimunri quartz diorite and hornblende diorite show that the ages are found to be $86{\pm}3.3$ Ma and $108{\pm}4$ Ma, respectively, and K-Ar age for chlorite from the altered two mica granite which intruded by the hornblende diorite of the Bonjeong mine shows $108{\pm}4$ Ma; K-Ar age for sericite from the greisenized hornblende diorite, which is closely associated with the Bonjeong ore deposits, is dated as $94.2{\pm}2.4$ Ma. They correspond to the igneous activity of the Bulgugsa Disturbance periods in the area. In chemical feature for oxides versus silica and AFM triagular diagrams of the pluton rocks in the study area, there is a suggestion of the possibility that these rock facies area a Calc-alkali series of differentiated products by low-pressure crystal fractionation processes in $SiO_2$-undersaturated suites. Compared with hornblende diorite, andesite and granodiorite porphyry, two mica granite, Rimunri quartz diorite and granophyre exhibit a wider range of normalized REE abundance and negative Eu anomalies. Such anomalies imply more extensive feldspar fractionation during crystallization. The Rimunri quartz diorite and hornblende diorite occurring in the margin of four mines(Bonjeong, Okdong, Soungchei and Saungyeul) of this area have high contents of As, Sb, Cu and Zn which have been shown as the best indicators in hypogene gold deposits and low contents of Ba, Cr served as more sensitive indicators. And the granitoids are regarded as the rocks associated with gold and sulfide mineralization of the area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.10-27
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• 2005

In this paper, we propose a high level design architecture of WCDMA(UMTS) base station modem and synchronization algorithms applied to the proposed architecture. Also analysis of each synchronization algorithm and performance evaluation of fixed point designed modem are shown. Since the target system is base station modem, each synchronization algorithm is designed for its stable operation. To minimize implementation complexity, optimum fixed point design for best operation of synchronization algorithms is performed. We performed symbol level link simulation with fixed point designed modem simulator for data rate of 12.2kbps, 64kbps, 144kbps, and 384kbps. We compared performance results to the minimum requirements specified in 3GPP TS 25.104(Release 5). Extensive computer simulation shows that the proposed modem architecture has stable operation and outperform the minimum requirement by 2 dB. The proposed modem architecture has been applied in the implementation of WCDMA reverse link receiver modem chip successfully.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.65-75
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• 2005

Moving-objects databases should efficiently support database queries that refer to the trajectories and positions of continuously moving objects. To improve the performance of these queries. an efficient indexing scheme for continuously moving objects is required. To my knowledge, range queries on current positions cannot be handled by the 3D R-tree and the TB-tree. In order to handle range queries on current and past positions. I modified the original 3D R-tree to keep the now tags. Most of spatio-temporal index structures suffer from the fact that they cannot efficiently process range queries past positions of moving objects. To address this issue. we propose an access method, called the Tagged Adaptive 3DR-tree (or just TA3DR-tree), which is based on the original 3D R-tree method. The results of our extensive experiments show that the Tagged Adaptive 3DR-tree outperforms the original 3D R-tree and the TB-tree typically by a big margin.

• Archives of Plastic Surgery
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• v.37 no.6
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• pp.801-807
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• 2010

Purpose: Facial rejuvenating surgery has become a challenge to most plastic surgeons. Patients are demanding fewer complications, a prompt recovery, and more natural results. Current trend of the face lift surgery has been developed into less invasive procedures. Every aging patient in Asia wants to look younger without obvious evidence of surgical correction. Methods: The authors performed the limited dissection face lift with PDS quilting suture on twenty five patients. These five quilting sutures consist of sutures at 1~2 cm posterior to the prominent point of zygoma to the periosteum of the zygomatic arch, at the lateral border of Bichat's fat pad area to the zygomatic arch, at the lateral border of the orbicularis oculi muscle to the deep temporal fascia, at the upper lateral border of the platysma to the periosteum of the mastoid, and at the anterior lower margin of the earlobe to the deep temporal fascia by quilting suture technique to achieve rejuvenation. Results: These procedures could produce a balanced volumetric rejuvenation. This method gave considerable benefit of stable and satisfactory results. It provides reduced operative time, well corrected nasolabial fold and neck wrinkle, and swift recovery with minimal complications. Conclusion: Although it could not replace the classic facelift, this technique can be recommended as an option for patients who do not present with advanced facial aging or not want a more extensive procedure.