• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.364-373
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• 2011

Human embryonic stem cells have been highlighted as a valuable cellular source in the regenerative medicine field, due to their pluripotency. However, there is the challenge of the establishment of specific functional cell type forms of undifferentiated human embryonic stem cells (hESC). To establish and purify functional cell types from hESCs, we differentiated undifferentiated hESCs into vascular lineage cells and sorted the specific cell population from the whole cell population, depending on their cell volume, and compared them with the non-sorted cell population. We observed that about 10% of the PECAM positive population existed in the VEGF induced differentiating human embryoid body (hEB), and differentiated hEBs were made into single cells for cell transplantation. After making single cells, we performed cell sorting using a fluorescence-activated cell sorter (FACs), according to their cell volume on the basis of FSC region gating, and compared their therapeutic capacity with the non-sorted cell population through cell transplantation into hindlimb ischemic disease model mice. 4 Weeks after cell transplantation, the recovery rate of blood perfusion reached 54% and 17% in the FSC regions of sorted cells- and non-sorted cells, respectively. This result suggests that derivation of a functional cell population from hESCs can be performed through cell sorting on the basis of cell volume after preliminary differentiation induction. This approach may then greatly contribute to overcoming the limitations of marker sorting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.395-399
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• 2017

The LPI fuel filter housings used in automobiles were made from conventional die castings but have recently been developed by cold forging to improve the weight and durability. On the other hand, a sink may develop at the core of the forged product due to the resulting T-shape, which not only reduces the aesthetics, but also increases the post-processing cost of the product. Therefore, this research focused on methods to predict and mitigate sink development and progression during the T-shape forging process. Finite element analysis of the forging process was first performed to determine the optimal initial workpiece devoid of burrs and underfills. An accurate sink prediction was then obtained via metal flow analysis, which was a result of the finite element simulation. Through finite element analysis, it was confirmed that sink development is a product of the differences in nodal velocities arising from the T-shaped forging process. Consequently, a pad was inserted beneath the sink to minimize these velocity differences. The results yielded significant improvement with regard to the sink defect. This method was practically applied to an industrial site to validate the sink improvement.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.60-70
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• 2011

Conventional content management systems are independently developed for a specific field in general. Therefore usage of contents for the CMS will be limited to the corresponding CMS field. These characteristics might reveal a defect that CMS could not support effectively in exchange and sharing of information between CMSs. On the other hand, metadata standardization shows big differences in method and representation for the fields of CMS because all metadata standardizations are variously performed according to applications of them. There are lots differences that make interoperability between CMSs impossible. In this paper, we propose a novel metadata schema based on METS(metadata encoding and transmission standard) so that metadata standardization can be fulfilled in reality and solved the problem of duplicated contents created from different CMSs. This framework of integrated metadata proposed here can offer an interoperability between contents created by different CMSs, and discard duplicated contents. As a result of the proposed technology, we obtain 0.5% duplication rate from traditional 10.3%. In addition the filtering ability of duplicated contents shows from 92% to 96%, which proves the effectiveness and stability of the proposed technology.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.19
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• pp.33-66
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• 2003

This is a comparative and analytical study which comprises of the analysis of the rules of the buyer's remedies where the seller delivers defective goods of four legal systems; Directive, CISG, English law and Korean law. In light of threefold main purposes of this study, it firstly attempts to describe and analyze the remedy provisions of Directive in a comparative way in order to provide legal advice to the sellers who plans to enter into English consumer markets. It shows that the two tier remedial system under Directive is not much different from the other jurisdictions, except where the right of rescission under Directive is absolute in a sense that it does not require a certain degree of seriousness of defect. Secondly, the study compares the rules of one jurisdiction with those of other jurisdictions and evaluates the rules in light of the discipline of comparative law the basic question of which is whether a solution from one jurisdiction may facilitate the systematic development and reform of another jurisdiction. It proves the followings; (1) the reluctance and uncertainty in English law of ordering specific performance based on the discretionary power does not reflect the parties' preference because the order is either uncertain or rather negative where the purchase of substitute goods elsewhere is not a satisfactory solution in many cases; (2) the position in Korean law which has no limitation on the right to require substitute goods is likely unfair in commercial sales, but justified in consumer sales; (3) the right of termination or reduction under Directive which is subject to the applicability of the right to require repair or substitute goods seems to be contrary to the consumer's preference where the defective delivery destroys the basis of trust in the quality of the seller's performance; (4) the absolute right of termination under Directive and English law seems crucial in consumer sales because they are often inferior to commercial sellers in terms of information and bargaining power; (5) the right of reduction as a self-help remedy which is absent in English law emphasizes its usefulness. Thirdly, it finds that, where CISG is deemed to fail to unify different rules on the right to require specific performance between Civil and Common law, it is attempted once again in Directive and notwithstanding their hostility to awarding the right to require specific performance in English law, Regulations 2002 expressively stipulates such right.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.1-7
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• 2008

The paper is to solve the problem of existing sound system, which has difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new sound system based on PLC and studied it. A transmitter and a receiver were designed using the PLC chip INT5500CS. Sound system was configured with a CD player that sound signals are sent from the transmitter and a speaker connected to the receiver. For analysis of characteristics of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is $2{\sim}3$[dB] lower than reference signal, latency is 16.69[ms] and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90[%] in good condition as a result of measuring pink noise, frequency(1kHz), and phase, magnitude. In view of the result so far achieved, the system designed our team has excellent performance, it resolves defect of existing audio signal transmition system.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.33-42
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• 1987

Congenital origin intestinal obstruction are important disease due to required emergency operation. So accurate and rapid diagnosis is needed for decreased mortality and morbidity. Radiologist must detect to accurate obstruction site and also associated other congenital anomalies. And also embriological bases are very important role to the diagnosis of theses diseases. We were analysed radiologically and clinically 25 cases with congenital origin intestinal obstruction with review of literature. 1. Hypertrophic pyloric stenosis 6 cases, midgut malrotation 4 cases, congenital megacolon 8 case, imperforated anus 5 cases, ileal atresia 1 case and duodenal atresia 1 case. 2. Male and female radio were 16:9. Especially on hypertrophic pyloric stenosis, 5 cases were male infants. 3. All cases of hypertrophic pyloric stenosis represented string sign and also pyloric beak sign shoulder sign on UGI. 4. I case duodenal atresia showed double bubble sign on simple abdomen x-ray and ileal atresia showed mechanical small bowel obstruction sign with microcolon. 5. On midgut malrotation, cecum was located in right upper abdomen on 4 cases. And 2 cases were associated with Ladd's band. I case with volvulus and 1 case with mesenteric defect. 6. Involved site of all congenital megacolon were localized to rectosigmoid colon. 7. On 5 cases imperforated anus, 3 cases were low type and 2 case high type. Rectoperineal and rectourogenital fistula were demonstrated on 4 cases.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.461-477
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• 2017

Organosilicone-based surfactants, consisting of hydrophobic organosilicone groups coupled to hydrophilic polar groups, have been widely used in many industrial fields starting from polyurethane foam to construction materials, cosmetics, paints & inks, agrochemicals, etc., because of their low surface tension, lubricity, spreading, water repellency and thermal and chemical stability, resulted from the unique properties of organosilicone. Especially, organosiloxane surfactants, having low molecular weight siloxane as hydrophobe, exhibit low surface tension and excellent wettability and spreadability, leading to their applications as super wetter/super spreader, but have the disadvantage of vulnerability to hydrolysis. A variety of low molecular weight siloxane surfactant structures are required to provide the functional improvement and the defect resolution for reflecting the necessities in the various applications. This review includes the synthetic schemes of reactive tetrasiloxanes and disiloxanes as hydrophobic siloxane backbones, the main reaction schemes, such as hydrosilylation reaction, for coupling reactive tetrasiloxanes or disiloxanes to hydrophilic groups, and the main synthetic schemes of the tetra- and di-siloxane surfactants having polyether-, carbohydrate-, gemini-, bola-type surfactant structures.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.512-519
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• 2007

The purpose of this study is to investigate the potential of a novel tissue engineering approach to regenerate intervertebral disc. In this study, thermosensitive scaffold (chitosan-Pluronic hydrogel) and nanofiber were used to replace the nucleus pulposus (NP) and annulus fibrosus of a degenerated intervertebral disc, leading to an eventual regeneration of the disc using the minimally invasive surgical procedure and organ culture. In preliminary study, disc cells were seeded into the scaffolds and cellular responses were assessed by MTT assay and scanning electron microscopy (SEM). Based on these results, we could know that tissue engineered scaffolds might provide favorable environments for the regeneration of tissues. Organ culture was performed in fresh porcine spinal motion segments with endplates on both sides. These spinal motion segments were classified into three groups: control (Intact), injured NP (Defect), and inserting tissue engineered scaffolds (Insert). The specimens were cultivated for 7 days, subsequently structural stability, cell proliferation and morphological changes were evaluated by the relaxation time, quantity of DNA, GAG and histological examination. In these results, inserting group showed higher relaxation time, reduced decrement of DNA contents, and accumulated GAG amount. Consequently, the tissue engineered scaffolds used in this study seen to be a promising base scaffolds for regenerative intervertebral disc due to its capacity to absorb external dynamic loading and the possible ideal environment provided for disc cell growing.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.115-120
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• 2009

Purpose: To evaluate the outcomes of three different surgical approaches in treating a distal radius fracture with dorsal communition. Materials and Methods: From April, 2006 to May, 2009, 49 patients over age of 60years old with unstable dorsal communition distal radius fracture were analyzed. We compared maintainability of reduction by radiological follow-up observations and clinical outcomes using Mayo wrist scores. One-Way ANOVA test was performed to examine the statistical correlation between the methods. Results: All three approaches provided satisfactory post-op reduction results. However, follow-up observations showed significant loss of reduction in the external fixation only group compared to the added bone graft group and the volar anatomical locking plate group (P<0.05). Mayo wrist score was indifferent between the three groups. Conclusion: Treatment of a distal radius fracture with severe dorsal communition using an external fixation only appears to be insufficient in maintaining reduction of a cancellous bone defect.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.668-674
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• 2000

Objective : The classic and accepted surgical method of compound comminuted depressed skull fractures (FCCD) involves total resection of all the contaminated bone and fragments at the fracture site. A second operation for cranioplasty is then performed at a later date. However, we have believed that primary repair of these bony defects can be achieved by the replacement of bone fragments at the time of the initial debridement, and this can be accomplished without danger to patient. The authors retrospectively reviewed the surgical results to assess the advantages and disadvantages, and also propose the selection criteria of replacement of fractured bone fragments as a primary procedure in FCCD. Materials and Methods : The authors analyzed the data extracted from medical records, and radiological findings in 22 of 71 patients with FCCD, who underwent immediate replacement of fractured bone fragments between April 1993 and October 1998. The mean follow-up period was 13.7 months. The selection criteria for the operation included the patients with mild to moderate severity, regardless of the degree of contamination or dural violation, which presented in hospital within 24 hours of injury. Results : The ages of the patients varied from 4 to 63 years, and there were 20 males and 2 females. Seventeen of 22 patients were fully conscious on admission and the others also had relatively good Glasgow coma scales. Sixteen fractures were located in the frontal area, 9 with involvement of the frontal sinuses, and 6 in the parietal and temporoparietal areas. Of the 22 patients, 8(36.3%) had dural lacerations with 3 of these requiring patching with pericranium, and 12(54.5%) had intracranial hematoma requiring wide craniotomy. The degree of wound contamination was also variable. Fifteen patients had relatively clean wounds, while seven(31.8%) had seriously contaminated wounds with soil, sand, hair, and wood. Only one patient(4.5%) developed infection, and the bone fragments were removed. All wounds healed primarily without pulsatile defect, the skull has remained solid, and no complications have occurred, except the infected case. Conclusion : It is proposed that bone fragments removal for FCCD, regardless of the degree of contamination or dural violation, is not necessary and that primary bone fragments replacement avoids a second operation for cranioplasty.