• Membrane Journal
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• v.17 no.3
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• pp.161-173
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• 2007

Membrane filtration processes are increasingly popular for drinking water treatment that requires high quality of water. Low pressure membrane(LPM) processes such as microfiltration(MF) and ultrafiltration(UF), however, are ineffective in the removal of dissolved organic matter and also membrane fouling is still an important issue to be resolved. High pressure membranes(HPMs) may guarantee better water quality, but at the high energy consumption. Thus, various approaches to combine LPM processes with other physicochemical methods have been recently made to achieve their efficiency to the level comparable to that of HPM processes. In this work, therefore, hybrid processes that coupled MF/UF with coagulation, adsorption, chemical reactions(e.g., chelation and oxidation) are reviewed regarding system design and performance and also membrane surface modifications conducted by grafting and polyelectrolyte multilayer formation were assessed.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.44-51
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• 2006

In this paper, we present a network-based integrated nesting system, that is adapted a current engineering concept. Generally, sheet cutting processes proceed in turn following an existing order In this study, however, the special characteristics of these processes were analyzed and the processes were redesigned with distributed design so that they could be operated in a client/server environment. Also, the necessary sheet material cutting processes, part CAD, nesting, part CAM, and NC post-processor capabilities, were implemented so that many workers could handle them all on the Web. Compared to existing commonly used systems, the developed system can provide integrated work environment for cutting automation, allow job collaboration between workers, and it has proved that it can shorten the standby time for work. By grafting computer system technologies to sheet material cutting automation field, this research expects to contribute to the enhancement of factory automation efficiency and productivity.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.651-655
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• 2011

We synthesized a novel cationic dendrimer consisting of a poly(amidoamine) dendrimer (PAMAM, generation 4) backbone with both L-arginine (Arg) at the termini and 6-aminohexanoic acid (Ahx) between the original core polymer and the peripheral Arg units. The sequential chemical modification of PAMAM G4 with Ahx and Arg resulted in higher transfection efficiency with much less cytotoxicity. PAMAM G4-Ahx-Arg formed stable polyplexes at weight ratios of 8:1 or higher (polymer: plasmid DNA), and the mean polyplex diameter was $180{\pm}20nm$. PAMAM G4-Ahx-Arg showed much higher transfection ability than PAMAM G4 or PAMAM G4-Ahx. Furthermore, PAMAM G4-Ahx-Arg was much less cytotoxic than PEI25KD and PAMAM G4-Arg. In addition to Arg grafting of the PAMAM dendrimer, which endows a higher transfection capability, the addition of Ahx spacer increased dendrimer hydrophobicity, introduced flexibility into the conjugated amino acids, and reduced cytotoxicity. Overall, it appears that the concomitant modification of PAMAM with Ahx and Arg could lead to new PAMAM conjugates with better performances.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.127-133
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• 2008

Purpose: The purpose of this study is to evaluate the remodeling process of the various skin substitutes in 4th and 6th weeks following the transplantation when transplanted onto nude mice. Methods: Three types of artificial skin substitutes, such as PLGA scaffold with keratinocyte sheets(group 1), acellular human dermis($Surederm^{(TM)}$) and keratinocyte sheet(group 2), bioengineered skin($Neoderm^{(TM)}$)(group 3), were applied to the wound on nude mice. All mice were killed in 2, 4 weeks and/or 6 weeks after grafting and tissue samples were harvested from the back of mice. The changes in wound size, degree of angiogenesis, formation of basement membrane and epidermis, density of collagen fibers and neural restoration were examined. Results: There was no significant changes in wound size among the three groups. However, the size of wound decreased in the non-substituted group due to contracture. Degree of angiogenesis and systhesis of collagen or neurofilaments were mostly increased in bioengineered skin($Neoderm^{(TM)}$)(group 3), followed by acellular human dermis($Surederm^{(TM)}$) and keratinocyte sheet(group 2), PLGA scaffold with keratinocyte sheets (group 1). However, group 3 and group 2 showed similar thickness of basement membrane and epidermis. Conclusion: We found that degree of angiogenesis, formation of basement membrane and skin appendages, density of collagen fibers and neurofilaments can be the categories to evaluate the success of artificial skin substitution in early stages.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.489-499
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• 2012

Most roads in Korea are constructed through a riverside or among the mountains due to geographical characteristics, and composed of various connection roads and complex networks, which makes it susceptible to a fog, rainfall and snowfall and causes serious negligent accidents due to misperception of network while driving. This study amis at securing original technology to provide traffic information, utilizing the road surface by grafting LED and optical technology highly recognized in terms of energy efficiency recently onto ITS, thereby developing next-generation ITS service. To support the research development, H/W was developed and field test was conducted. In addition, the customer satisfaction survey towards equipment, an end product of this research development was also carried out to find out what it means to customers potentially.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.109-117
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• 2010

The ultimate purpose of this study is to propose a method to improve water supply management efficiency which is one of the two main approaches to solve the water supply-related problems. As an effort, targeting commercial water, a series of efforts was performed such as choosing a field area, selecting a sensing point, installing a sensor and server systems, and monitoring the real time data. Through the analyses of the real time data gathered, a series of water consumption trend analysis models were developed for each day and for each month. And Also proposed are the related utilization of the developed trend analysis models and a GIS. As a result of the aforementioned research, the proposed trend analysis technique is expected to offer some important role for the water supply forecasting agministation and management.

• Advances in environmental research
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• v.5 no.1
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• pp.1-18
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• 2016

Magnetic nano-based sorbents have been synthesized for the recovery of two rare earth elements (REE: Nd(III) and Yb(III)). The magnetic nano-based particles are synthesized by a one-pot hydrothermal procedure involving co-precipitation under thermal conditions of Fe(III) and Fe(II) salts in the presence of chitosan. The composite magnetic/chitosan material is crosslinked with epichlorohydrin and modified by grafting alanine and serine amine-acids. These materials are tested for the binding of Nd(III) (light REE) and Yb(III) (heavy REE) through the study of pH effect, sorption isotherms, uptake kinetics, metal desorption and sorbent recycling. Sorption isotherms are well fitted by the Langmuir equation: the maximum sorption capacities range between 9 and 18 mg REE $g^{-1}$ (at pH 5). The sorption mechanism is endothermic (positive value of ${\Delta}H^{\circ}$) and contributes to increase the randomness of the system (positive value of ${\Delta}S^{\circ}$). The fast uptake kinetics can be described by the pseudo-second order rate equation: the equilibrium is reached within 4 hours of contact. The sub-micron size of sorbent particles strongly reduces the contribution of resistance to intraparticle diffusion in the control of uptake kinetics. Metal desorption using acidified thiourea solutions allows maintaining sorption efficiency for at least four successive cycles with limited loss in sorption capacity.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.5
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• pp.276-284
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• 2019

Objectives: This study sought to compare efficiency results between the use of a customized implant (CI) and a reconstruction plate (RP) in mandibular defect reconstruction in an animal model. Materials and Methods: Fifteen rabbits underwent surgery to create a defect in the right side of the mandible and were randomly divided into two groups. For reconstruction of the mandibular defect, the RP group (n=5) received five-hole mini-plates without bone grafting and the CI group (n=10) received fabricated CIs based on the cone-beam computed tomography (CBCT) data taken preoperatively. The CI group was further divided into two subgroups depending on the time of CBCT performance preoperatively, as follows: a six-week CI (6WCI) group (n=5) and a one-week CI (1WCI) group (n=5). Daily food intake amount (DFIA) was measured to assess the recovery rate. Radiographic images were acquired to evaluate screw quantity. CBCT and histological examination were performed in the CI subgroup after sacrifice. Results: The 1WCI group showed the highest value in peak average recovery rate and the fastest average recovery rate. In terms of reaching a 50% recovery rate, the 1WCI group required the least number of days as compared with the other groups ($2.6{\pm}1.3days$), while the RP group required the least number of days to reach an 80% recovery rate ($7.8{\pm}2.2days$). The 1WCI group showed the highest percentage of intact screws (94.3%). New bone formation was observed in the CI group during histological examination. Conclusion: Rabbits with mandibular defects treated with CI showed higher and faster recovery rates and more favorable screw status as compared with those treated with a five-hole mini-plate without bone graft.

• Journal of Dairy Science and Biotechnology
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• v.40 no.4
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• pp.143-150
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• 2022

Maillard conjugates are formed by covalent bonds between proteins and polysaccharides. Understanding the functional properties of Maillard conjugates, including emulsifying and antioxidant properties, can be crucial when Maillard conjugates are used in processed foods. This study aimed to manufacture whey protein isolate (WPI)/Inulin Maillard conjugates and investigate how manufacturing variables including heating temperature and pH affect the functional properties of Maillard conjugates. The surface properties, emulsifying properties, and antioxidant properties of Maillard conjugates were assessed by varying heating temperature and pH. The grafting degree of WPI/Inulin Maillard conjugates increased with increasing pH and heating temperature, indicating enhanced conjugation efficiency. Surface hydrophobicity, emulsifying properties (including emulsifying activity index and emulsifying stability index), and ABTS radical scavenging ability of WPI/Inulin Maillard conjugates increased as pH and heating temperature were increased. In conclusion, WPI/Inulin Maillard conjugates were successfully manufactured, and pH and heating temperature were critical factors in enhancing Maillard conjugate functional properties.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.322-327
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• 2004

Coronary artery bypass grafting on the beating heart is no longer a new methods for any cardiac surgeon. We evaluated the application of the off-pump coronary artery bypass procedure relative to safety and efficiency as measured by postoperative complication and operative mortality. Material and Method: We used our retrospective database to compare the patients having off-pump coronary surgery (n=100) with those having on-pump coronary surgery (n=100) between June, 1999 and August, 2002. Patients whom underwent associated valvular or aortic aneurysmal operation were excluded. Result: Neither groups showed any differences in the patient's risk factors and extent of coronary disease. Off-pump CABG group did not have significantly less mean operation time (295$\pm$73 min vs 323$\pm$83 min, p=ns) and mean hospital day (15.34$\pm$6.02 day vs 13.80$\pm$4.95 day, p=ns). However, off-pump CABG group had significantly shorter mean ventilation time (17.3$\pm$11.27 hour vs 24.98$\pm$16.1 hour, p＜0.05). No patients were converted to on-pump CABG in off-pump CABG. Intraoperative hemodynamic instability in off-pump CABG were 6 cases, of whom 2 cases were in lateral wall approach and 4 cases in right coronary anastomosis. Postoperative mortality was 1 case in off-pump CABG and 2 cases in on-pump CABG. Intra-aortic ballon pump (IABP) was applied in 1 case with off-pump CABG and in 2 cases with on-pump CABG. No patients presented postoperative cerebral infarction ＆ stroke in off-pump CABG but 2 patients in on-pump CABG. Postoperative arrhythmia presented in 4 cases with off-pump CABG and in 6 cases with on-pump CABG. Acute renal failure (ARF) was complicated in 3 cases with off-pump CABG and in 2 cases with on-pump CABG. Conclusion: This study documented the immediate safety and efficiency of the off-pump CABG procedure.