• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.391-393
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• 2005

IEEE 802.16은 BWA (Broadband Wireless Access) 시스템의 표준으로 현재 많은 연구와 함께 상용 제품에 대한 연구가 진행중인 분야이다. IEEE 802.16에서는 QoS를 제공하기 위하여 BS (Base Station)와 SS(Subscriber Station)간의 QoS 협상 과정을 정의하고 있으며, BS 및 SS에서의 효율적인 QoS 보장을 위해 4가지의 서비스 클래스를 정의하고 있다. 이러한 서비스 클래스는 UGS, rtPS, nrtPS, 그리고 BE 이다. 하지만 표준에서는 이러한 서비스 클래스를 어떻게 이용할 것인지에 대한 언급이 없으며, 이에 따라 효율적인 packet scheduling에 관한 많은 연구가 진행되어 왔다. 기존의 연구에서는 주로 BS에서의 효율적인 Scheduling에 초점을 맞추어 연구가 진행되었으며, SS에서의 Scheduling에 대한 연구는 거의 되어 있지 않다. 하지만 BS에서 SS에게 대역폭을 할당할 때 GPSS (Grants per subscriber station) mode로 대역폭을 할당한다면 SS에서는 할당 받은 대역폭을 효율적으로 사용하기 위하여 scheduling이 필요하다. 본 논문에서는 SS에서의 scheduling architecture를 제안하고자 한다. 제안하는 scheduling architecture는 기존의 scheduling algorithm과는 달리 각 서비스 클래스에 대해서 효과적인 scheduling이 가능하도록 함으로써 시스템의 성능을 높이는데 기여할 것이다.

• Toxicological Research
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• v.12 no.2
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• pp.295-303
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• 1996

Acute toxic effects of the Woo Whang Chung Shim Won suspension and pills were studied with the doses of 60, 74, 90, and 110 ml/kg in mice. In this study, we daily examined number of deaths, clinical signs, body weights, and pathological findings for 7 days after administration of Woo Whang Chung Shim Won. All mice given the highest dose (110ml/kg) died at 24 hour after administration of Sam-Sung Woo Whang Chung Shim Won suspension (Byunbang, SS-BS and Wonbang, SS-WS), one male and two female mice given 90 ml/kg dose of SS-BS died, and a few mice given middle dose (74 ml/kg) of SS-WS died. In control group (110 ml/kg) treated with vehicle (SS-BS and SS-WS), three out of 5 males and two out of 5 females mice died during the study. However, in animals treated with Kwang-Dong Woo Whang Chung Shim Won suspension (KD-S) and pill (KD-P), deaths were not observed. In the clinical signs, increase of drooling and decrease of spontaneous motor activities were observed in the highest dose group (110 ml/kg). No significant dose-related change in body weight was observed. The results suggest that the toxic effect of SS-BS and SS-WS may be atttributed to the solution for the Woo Whang Chung Shim Won suspension.

• Molecules and Cells
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• v.38 no.1
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• pp.33-39
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• 2015

The correction of disease-causing mutations by single-strand oligonucleotide-templated DNA repair (ssOR) is an attractive approach to gene therapy, but major improvements in ssOR efficiency and consistency are needed. The mechanism of ssOR is poorly understood but may involve annealing of oligonucleotides to transiently exposed single-stranded regions in the target duplex. In bacteria and yeast it has been shown that ssOR is promoted by expression of $Red{\beta}$, a single-strand DNA annealing protein from bacteriophage lambda. Here we show that $Red{\beta}$ expression is well tolerated in a human cell line where it consistently promotes ssOR. By use of short interfering RNA, we also show that ssOR is stimulated by the transient depletion of the endogenous DNA mismatch repair protein MSH2. Furthermore, we find that the effects of $Red{\beta}$ expression and MSH2 depletion on ssOR can be combined with a degree of cooperativity. These results suggest that oligonucleotide annealing and mismatch recognition are distinct but interdependent events in ssOR that can be usefully modulated in gene correction strategies.

• Corrosion Science and Technology
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• v.18 no.3
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• pp.73-77
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• 2019

Hot-dip aluminized coating has been widely used to protect steel substrate against corrosion. In this study, the corrosion behavior of hot-dip aluminized type 409L (11% Cr) stainless steel (SS) was investigated using macro- and micro-scale polarization tests. An Al-Fe-Si alloy layer that was formed due to inter-diffusion of alloying elements between Al coating and SS substrate was observed between Al coating and 409L SS substrate. In both macro- and micro-scale polarization tests, the corrosion potential ($E_{corr}$) of the 409L SS substrate was much nobler than that of the Al coating and alloy layer. $E_{corr}$ of the alloy layer was between that of Al coating and 409L SS substrate. This indicates that the alloy layer can act as a buffer between the more active Al coating and the nobler SS substrate for pit growth in aluminized SS. The presence of the alloy layer appears to be helpful in hindering pitting corrosion of aluminized SS.

• Advances in concrete construction
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• v.13 no.4
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• pp.281-289
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• 2022

3D printing cement-based materials (3DPCBM) is an innovative rapid prototyping technology for construction materials. This study is tested on the rheological behavior, printability and buildability of steel slag (SS) content based on the extrusion system of 3D printing. 0, 8 wt%, 16 wt%, 24 wt%, 32 wt% and 40 wt% SS was replaced cement, The test results revealed that the addition of SS would increase the fluidity of the printed paste, prolong the open time and setting time, reduce the plastic viscosity, dynamic yield stress and thixotropy, and is beneficial to improve the pumping and extrudability of 3DPCBM. With the increase of SS content, the static yield stress developed slowly with time which indicated that SS is harmful to the buildability of printing paste. The content of SS in 3DPCBM can reach up to 40% at most under the condition of satisfying rheological property and buildability, it provides a reference for the subsequent introduction of SS and other industrial solid waste into 3DPCBM by explored the influence law of SS on the rheological properties of 3DPCBM.

• Safety and Health at Work
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• v.14 no.4
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• pp.431-437
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• 2023

Background: Depressive symptoms (DS) can erode physical and mental health; social support (SS) is considered a buffer for DS and a promoter for improving coping and recovery abilities. However, there is almost no research on the mediating role of negative coping (NC) in SS and DS, especially among firefighters. Methods: A cross-sectional survey was conducted among firefighters in Chongqing, China, and the valid data of 407 firefighters were collected through questionnaires distributed on the WeChat platform in 2020. Statistical Product and Service Solutions (SPSS) 26.0 is used for descriptive statistics and correlation analysis. Structural equation modeling was adopted to analyze the association among SS, NC, and DS. The mediation effect is also evaluated. Results: Firefighters' detection rate of DS is 23.3%, and when they receive more SS were less likely to develop DS. NC was positively correlated with DS (β = 0.54, p < 0.001) after controlling for SS. Besides, the results of structural equation modeling showed that NC partially mediates the relationship between SS and DS (standard error = 0.039, indirect effects = 0.109, 95% confidence interval: 0.047-0.200 p < 0.001). Conclusion: NC has a partial indirect effect between SS and DS among firefighters. SS could not only affect DS directly but also indirect work on it by affecting NC. This discovery will be a novel and meaningful part of the research on the firefighter population.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.377-383
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• 1997

Yttria-stabilized TZP alloyed with pentavalent oxides $(Ta_2O_5,\;Nb_2O_5)$ were fabricated by the conventional sintering method at $1500^{\circ}C$ in air to construct the simplified ternary phase diagram. The phase stability of tetragonal -$ZrO_2$ from the quasi-binary system $ZrO_2-YTa(Nb)O_4$, which do not transform to monoclinic-$ZrO_2$ even for a wide range of grain size and annealing temperature, was investigated to determine composition region of the non-transformable $t-ZrO_2$ solid solution$(NT_{ss})$. Phase stability of $NT_{ss}$ was probably due to the enhanced stability of $_YTa(Nb)O4$ having the tetragonal fergusonite structure. It was experimentally found that mixtures having $NT_{ss}$ alloyed with $T_{ss}$ by weight%% showed both excellent phase stability of $t-ZrO_2$ and fracture toughness even though the calculated composition of the mixture /was located outside $NT_{ss}$ composition region.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.91-99
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• 2017

The objective of this research was to investigate runoff characteristics of suspended solid (SS) and chemical oxygen demand (COD) from a paddy field watershed during storm events in the growing and non-growing seasons. Average of event mean concentration (EMC) of pollutants were 56.9 mg/L for SS and 23.9 mg/L for COD in the non-growing season and 50.3 mg/L for SS and 11.9 mg/L for COD in the growing season. The average EMC of SS in the study area was much lower than that in the uplands irrespective of cultivation, suggesting that paddy fields control soil erosion. This may be because flooding and wet soil in the growing season, and rice straw residue and stubble on the topsoil in the non-growing season reduce soil erosion. The changing tillage practice from fall tillage to spring tillage avoids soil erosion due to shortening of the tilled fallow period. However, the average EMC of COD in the non-growing season was about twice as much that in the growing season likely due to the runoff of organics like rice straw residues. The relationship between SS and COD loads and stormwater runoff volume was expressed by power function. The exponent for SS was higher than that for COD, suggesting that SS load increased with stormflow runoff more than COD load did. The mean SS and COD loads per storm during the non-growing season were much lower than those in the growing season, and therefore non-point source pollution in the growing season should be managed well.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.177-183
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• 2007

Using complementation of RpoH deficient E. coli strain A7448, the rpoH gene encoding heat shock sigma factor 32 (${\sigma}^{32}$) from Methylovorus sp. strain SS1 DSM11726 was cloned and sequenced. Sequence analysis of a stretch of 1,796-bp revealed existence of an open reading frame encoding a polypeptide of 284 amino acid (32,006 dalton). Deduced amino acid sequence of the Methylovorus sp. strain SS1 RpoH showed that 59.6%, 39.1% and 51.4% identities with those of Nitrosomonas europaea (${\beta}$-proteobacteria), Agrobacterium tumefaciens ($\alpha$-proteobacteria) and E. coli (${\gamma}$-proteobacteria). The expression level of the functional ortholog of RpoH of Methylovorus sp. strain SS1 was increased transiently after heat induction, further indicating that it functions as a heat shock sigma factor.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.24 no.4
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• pp.384-391
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• 2021

Purpose: The Cow's Milk-related Symptom Score (CoMiSS^TM) was developed as an awareness tool for evaluating cow's milk-related symptoms in otherwise healthy children. Using a convenience sample of participants, this cross-sectional study aimed to determine CoMiSS^TM values of symptomatic infants based on retrospectively or prospectively obtained information. Methods: CoMiSS^TM values were determined in infants aged <12 months with symptoms suggestive of cow's milk protein allergy or functional gastrointestinal disorders. The exclusion criteria were previous diagnosis with acute or chronic disease, treatment with a therapeutic formula, and in case of breastfeeding, an elimination diet followed by the mother. Two CoMiSS^TM values were assessed. A retrospective collection was defined as the collection of data after initial contact with the medical center but before the first medical consultation. A prospective collection was defined as the collection of data within 24 hours from the time of medical consultation but before starting any therapeutic intervention. The CoMiSS^TM total and individual component scores obtained retrospectively or prospectively were compared between groups using the Wilcoxon signed-rank test. Results: This study was performed between August and November 2019. Data of 110 children (62 males and 48 females), with a mean±standard deviation age of 18.2±11.7 weeks, were obtained. The total CoMiSS^TM value (p<0.001) and some individual component scores (crying, regurgitation, and stool) were significantly lower when collected prospectively than when collected retrospectively. Conclusion: CoMiSS^TM values were retrospectively and prospectively determined. Lower CoMiSS^TM values were obtained during prospective evaluation. Possible differences should be considered when using CoMiSS^TM in clinical practice.