• Journal of the Korean Magnetic Resonance Society
• /
• v.4 no.1
• /
• pp.12-18
• /
• 2000

Metakaolinite produced by thermal transformation from kaolinite was studied by 27Al multiple quantum magic angel spinning (MQMAS) NMR technique in addition to 1-dimensional 27Al and 29Si MAS NMR. Our results confirm that 4-, 5-, 6- coordinated aluminum sites co-exit with some distribution of isotropic chemical shifts. This is consistent with amorphous character of metakaolinite observed with X-ray diffraction. In addition, characterization with MQMAS is briefly discussed in comparison with other NMR techniques to identify different aluminum sites especially when peaks are severely overlapped in 1-dimensional 27Al MAS NMR spectra.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.21 no.1
• /
• pp.31-50
• /
• 1996

In this paper we prescribe a replication server scheme with an algorithm DRF (Differential Refresh File) to refresh multiple materialized views and replicas in distributed environments. Before sending relevant tuples in server sites to client sites, an effective tuple reduction scheme is developed as a preprocessor to reduce the transmission cost. Because it utilizes differential files with out touching base relations, the DRF scheme can help to minimize the number of locks, which enhances the system's performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.9
• /
• pp.78-83
• /
• 2006

A new measure, the distributed generation impact factor (DGIF), is used for evaluating the impact of newly introduced distributed generators on a networked distribution or a transmission system. Distribution systems are normally operated in a radial structure. But the introduction of distributed generation needs load flow calculation to analyze the networked system. In the developed framework, the potential share of every generation bus in each line flow of a networked system can be directly evaluated. The developed index does not require the solution of power flow equations to evaluate the effect of the distributed generation. The main advantage of the developed method lies in its capability of considering simultaneous outputs of multiple generation sites.

• Water for future
• /
• v.27 no.1
• /
• pp.133-140
• /
• 1994

The augmenting hydrologic data using a correlation procedue has been used to improve the estimates of the mean and variance at the site of interest with short record when one or more nearby sites with longer records are available. The variance of the unbiased maximum likelihood estimator of ${{\sigma}_v}^2$ derived by Moran based on the multivariate normal distribution is modified into the form of Matalas and jacobs for the bivariate normal distribution to get the critical minimum values of the multiple correlation coefficient which give the improvement for estimation the variance at the site of interest. Those values are tabulated for various lengths of records and the number of sites.

• The Journal of Society for e-Business Studies
• /
• v.3 no.1
• /
• pp.23-41
• /
• 1998

In a centralized database system, all system components reside at a single platform. In recent years there has been a rapid trend toward the integration of information systems over multiple sites that are interconnected via a communication network, and users' needs are changed to integration of multiple information sites. Multi database System is one of solutions for integrating distributed heterogeneous databases. However the problems in multi database system are restriction in distributed environment support, limitation in integrating heterogeneous media type data, static integration, and data-only of integration. In order to solve these problems, we propose a hybrid database integration model, HyDIM. HyDIM is used for the integrating legacy multimedia data, adopting CORBA, MDS, and mediator. We demonstrate a prototype system far PDM application domain.

• Korean Journal of Head & Neck Oncology
• /
• v.13 no.1
• /
• pp.58-61
• /
• 1997

Multiple primary cancer is defined as the discrete primary cancers in an individual originating in different sites or tissues. Billroth, in 1869, first reported the occurrence of different primary malignant cancers in the same patient. Because early diagnosis and treatment are key to good survival and cure rates, clinicians should be more aware of the possibility of multiple primary cancers in an individual patient with malignant tumor. The authors recently experienced a case of fifth primary cancer, their sites of origin were lung, glottis, lymph node, supraglottis, common bile duct. We report this case with a brief review of literatures.

• International journal of thyroidology
• /
• v.10 no.2
• /
• pp.127-132
• /
• 2017

Anaplastic transformation of differentiated thyroid cancer at distant metastatic sites is extremely rare and has a poor prognosis. It usually occurs in the thyroid gland or cervical lymph nodes. Here we report a case of anaplastic transformation arising at multiple distant metastatic sites including the lung, liver, adrenal gland, bone, and lymph nodes in a patient 3 years after total thyroidectomy for follicular thyroid cancer.

• Korean Journal of Head & Neck Oncology
• /
• v.21 no.2
• /
• pp.190-195
• /
• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• Korean Journal of Heritage: History & Science
• /
• v.39
• /
• pp.281-314
• /
• 2006

Several explanations exist about the usage of disk-shaped bronze implements in the ancient society. Some argue that they were used as mirrors, others suggest percussion instruments, and still others bronze ornaments. Differences between disk-shaped bronze implements and mirrors with multiple knobs are that the former have no visible design, only one handle, and a sharp curvature unlike the latter with smooth curvature. The question is whether disk-shaped bronze implements excavated from Korean peninsula have any light reflecting function. To answer this question, I carefully studied the concave surfaces of disk-shaped bronze implements excavated from Goejeong-dong, Tongso-ri and Hapsong-ri sites. The main findings are as follows: (1) The concave sides of the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites were highly polished, and they were as reflective as bronze mirrors. (2) The concave side of the disk-shaped bronze implement from Hapsong-ri site was unpolished, and it was different from bronze mirrors. (3) As for the convex sides of the disk-shaped bronze implements, they did not appear to have been polished with care. Considering the above findings, the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites belong to the stage where they could act as both mirrors and instruments. On the contrary, the disk-shaped bronze implement from Hapsong-ri site can belong to the stage where it lost the function of being a mirror as the result of maintaining only its function as an instrument. Even though disk-shaped implements had two functions, it can be considered that the light reflecting function expanded the role of a mirror with multiple knobs and the sound function helped the engraved round bronze implement to be converted into an eight-armed bronze rattle. Since it has been reported that shamans used bronze mirrors as percussion instruments in their performances in Korean peninsula and Siberia, I propose a reconsideration of the usage of mirrors in the ancient East Asia. Although the essential function of a mirror is to reflect light, other possible usages involving important functions need to be further investigated.

• Journal of Digital Convergence
• /
• v.11 no.4
• /
• pp.147-152
• /
• 2013

Now, plastic surgery has become the industry for beauty. In order to know the characteristics of high-visit web sites that many people have visited, 33 high visit websites of plastic surgery were compared to 60 benchmark sites of same industry. We selected 34 web site attributes that can be measured objectively from existing studies. For analysis, Multiple Discriminant Analysis(MDA) is conducted for searching what attributes divide two group definitely. The result of this study shows the dividing attributes fall into 2 categories like 'Community', 'Up to date'. Thus, we are able to conclude that high-visit plastic surgery web sites are community-centric site but not contents-centric and are maintained with tide up to date. The methodology employed in this study provides an efficient way of improving satisfaction of visitors of plastic surgery website.