• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.5
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• pp.1-17
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• 2013

We researched the fauna restoration of 5 urban streams in Ulsan established as ecological streams by improving water quality and river environment. The fauna inhabitation were compared according to the conditions of geometrical feature such as river width, low-water channel width, ect and water quality, water volumn, inland and forceland. The Mugeo cheon has clearly shown the fauna restoration effects resulting from supplying sustainable maintenance water and wastewater treatments. In the Yaksa cheon, on the other hand, the restoration effects were low due to the inflow of wastewater and sledges in some part of stream ever though the improvement of water quality. The Yeocheon cheon was found to have disadvantage on the ecological inhabitations due to supplying the maintenance water with highly concentrated salinity. The fauna restoration effect of the Meongjeong cheon was low due to the inflow of wastewater to the down stream. Therefore by supplying the maintenance water and improving the connection to the Taehwa river at the estuary, better restoration effects could be observed. In the Cheokgwa cheon, which is almost a natural river, the ecological integrity of the fauna population has been maintained quite well. It was concluded that the project to transform urban streams into ecological streams should focus on not only keeping water volume and quality but also maintaining favorable conditions for the migration and settlement of animal species close to the natural state.

• Toxicological Research
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• v.35 no.1
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• pp.9-12
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• 2019

One of the major challenges in methadone maintenance therapy (MMT) for drug dependence is the physiological side effects on endocrine hormones. Because of the key role of the thyroid gland in the normal functioning of the human body and brain, this study examined the effect of MMT on thyroid function. Thyroid hormones (T3, T4, and thyroid-stimulating hormone (TSH)) were evaluated in normal and user treated with MMT who were referred to the Province Clinical & Pathology Center of Urmia, Iran. The study was conducted for three months using the Case Series method. A total of 270 samples were collected, 215 were from individuals who were not treated, whereas 55 were from men treated with methadone. Average levels of T3 and T4 in non-treated sample of men are $1.34{\pm}0.02ng/mL$ and $90.96{\pm}1.38ng/mL$ while the corresponding values for patients treated with methadone are $1.39{\pm}0.04ng/mL$ for T3 and $94.57{\pm}2.72ng/mL$ for T4. Mean TSH levels of the non-treated group and the methadone consuming group were $1.75{\pm}0.08{\mu}IU/mL$ and $3.17{\pm}0.45{\mu}IU/mL$, respectively. These results indicate that although men treated with methadone had higher levels of T3, T4, and TSH than normal individuals, only the difference in TSH level was significant. The importance of this difference among individuals on methadone maintenance programs should be investigated in larger samples over long periods of time. Additionally, the effects of methadone treatment on women should be examined.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.3
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• pp.213-223
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• 2001

This paper presents an analytical procedure for the time-dependent analysis of the multi-story prestressed concrete structure under the construction stage. To account for the actual structural behavior, the procedure considers the effects due to the construction interval and the time-dependent losses of prestress at every construction step on the entire structural response. A numerical study is performed to demonstrate the general validity of the approach and to quantitatively evaluate the effects resulted from the time-dependent behaviors during construction. Recommendations and conclusions are developed by comparisons with structural responses using the present and conventional methods of analysis. The comparative results show that both effects of sequential construction and time-dependent prestress losses should be considered for the construction stage analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1398-1406
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• 2016

In general, the seminiferous tubule basement membrane (STBM), comprising laminin, collagen IV, perlecan, and entactin, plays an important role in self-renewal and spermatogenesis of spermatogonial stem cells (SSCs) in the testis. However, among the diverse extracellular matrix (ECM) proteins constituting the STBM, the mechanism by which each regulates SSC fate has yet to be revealed. Accordingly, we investigated the effects of various ECM proteins on the maintenance of the undifferentiated state of SSCs in pigs. First, an extracellular signaling-free culture system was optimized, and alkaline phosphatase (AP) activity and transcriptional regulation of SSC-specific genes were analyzed in porcine SSCs (pSSCs) cultured for 1, 3, and 5 days on non-, laminin- and collagen IV-coated Petri dishes in the optimized culture system. The microenvironment consisting of glial cell-derived neurotrophic factor (GDNF)-supplemented mouse embryonic stem cell culture medium (mESCCM) (GDNF-mESCCM) demonstrated the highest efficiency in the maintenance of AP activity. Moreover, under the established extracellular signaling-free microenvironment, effective maintenance of AP activity and SSC-specific gene expression was detected in pSSCs experiencing laminin-derived signaling. From these results, we believe that laminin can serve as an extracellular niche factor required for the in vitro maintenance of undifferentiated pSSCs in the establishment of the pSSC culture system.

• Journal of Korean Academy of Nursing
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• v.42 no.6
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• pp.791-798
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• 2012

Purpose: The purpose of this study was to analyze the effectiveness of saline solution vs. heparinized-saline for maintenance of arterial lines and to detect changes in platelet and aPTT as physiological indexes. Methods: In this nonequivalent control group, non-synchronized, double-blind study the effects of heparinized and saline solution on the maintenance of arterial lines were compared. Fifty five patients received the heparinized solution and fifty nine patients received the saline solution. All patients who had surgery in K-university hospital between September and December 2011 were eligible for participation in the study. Results: There was no statistically significant difference between the saline and the heparin group in the maintenance time of the arterial lines or the number of irrigations. There was no statistically significant difference between the groups in changes in the number of platelets and aPTT for interaction between the groups and time intervals. Conclusion: The results indicate that saline solution can be used as an irrigation solution for the maintenance of arterial lines of adult surgical patients, rather than heparinized-saline, in view of potential risk factors in the use of heparin.

• Molecules and Cells
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• v.40 no.2
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• pp.117-122
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• 2017

Despite the fact that porcine embryonic stem cells (ESCs) are a practical study tool, in vitro long-term maintenance of these cells is difficult in a two-dimensional (2D) microenvironment using cellular niche or extracellular matrix proteins. However, a three-dimensional (3D) microenvironment, similar to that enclosing the inner cell mass of the blastocyst, may improve in vitro maintenance of self-renewal. Accordingly, as a first step toward constructing a 3D microenvironment optimized to maintain porcine ESC self-renewal, we investigated different culture dimensions for porcine ICM-derived cells to enhance the maintenance of self-renewal. Porcine ICM-derived cells were cultured in agarose-based 3D hydrogel with self-renewal-friendly mechanics and in 2D culture plates with or without feeder cells. Subsequently, the effects of the 3D microenvironment on maintenance of self-renewal were identified by analyzing colony formation and morphology, alkaline phosphatase (AP) activity, and transcriptional and translational regulation of self-renewal-related genes. The 3D microenvironment using a 1.5% (w/v) agarose-based 3D hydrogel resulted in significantly more colonies with stereoscopic morphology, significantly improved AP activity, and increased protein expression of self-renewal-related genes compared to those in the 2D microenvironment. These results demonstrate that self-renewal of porcine ICM-derived cells can be maintained more effectively in a 3D microenvironment than in a 2D microenvironment. These results will help develop novel culture systems for ICM-derived cells derived from diverse species, which will contribute to stimulating basic and applicable studies related to ESCs.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.184.1-184
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• 2001

• Korean Journal of Construction Engineering and Management
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• v.7 no.4 s.32
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• pp.69-77
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• 2006

In recent years, there has been more reconstruction and redevelopment of apartments rather than efforts to consider alternative to extend the life time of the apartments. It is essential to try to develop ways to adequately maintain and to use the apartment facilities efficiently in order to preserve earth environment and the limited resource. However, tacking research on the effects obtained through remodelling and maintenance have interfered with the vitalizing of the market. The objective of this study is to propose criterions and methods with which to evaluate adequacy of maintenance management. A survey was performed to investigate important maintenance methods in order to obtain advices that can smoothly progress improve apartment maintenance management. This study applied AHP(Analytical Hierarchy Process) methods for reasonable maintenance in apartment. Through this study, the flow of apartment maintenance market is elevated to reaching the level in advanced nation.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.175-183
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• 2020

This study suggests a solution regarding the effects of apartment facility maintenance and fire safety facility maintenance on the residential satisfaction of residents. The results are as follows. Firstly, facility maintenance had a negative effect on residential satisfaction. Analysis revealed that residential satisfaction decreased the more breakdowns there were in the facilities. This revealed that when maintenance staff neglect the residents' complaints due to the repetitive aspect of their jobs, there was a negative effect on residential satisfaction; therefore, residential satisfaction must be increased by maintaining the facilities well and training support for maintenance staff. Secondly, fire safety facilities had a negative effect on residential satisfaction. Analysis revealed that residential satisfaction decreased the more malfunctions there were in the fire safety facilities and the more replacements there were in fire fighting equipment. This revealed the importance of safety and the fact that the apartment heavily relies on fire safety facilities because there may be a low awareness regarding safety; therefore, maintenance staff must lower the damage from fire safety facilities and to increase the residential satisafaction of residents. Lastly, there needs to be repetitive training and education for residents regarding fire fighting and evacuating in accordance with the fire fighting plan as a means to strengthen residents' safety awareness.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.25-32
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• 2006

LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.