• KIPS Transactions on Computer and Communication Systems
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• v.7 no.8
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• pp.195-202
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• 2018

With the development of location-based applications such as smart phones and GPS navigation, active research is being conducted to protect location and trajectory privacy. To receive location-related services, users must disclose their exact location to the server. However, disclosure of users' location exposes not only their locations but also their trajectory to the server, which can lead to concerns of privacy violation. Furthermore, users request from the server not only location information but also multimedia information (photographs, reviews, etc. of the location), and this increases the processing cost of the server and the information to be received by the user. To solve these problems, this study proposes the EGTC (Enhanced Grid-based Trajectory Cloaking) technique. As with the existing GTC (Grid-based Trajectory Cloaking) technique, EGTC method divides the user trajectory into grids at the user privacy level (UPL) and creates a cloaking region in which a random query sequence is determined. In the next step, the necessary information is received as index by considering the sub-grid cell corresponding to the path through which the user wishes to move as c(x,y). The proposed method ensures the trajectory privacy as with the existing GTC method while reducing the amount of information the user must listen to. The excellence of the proposed method has been proven through experimental results.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.724-729
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• 2013

Simultaneous nitrification and denitrification (SND) occurs concurrently in the same reactor under micro dissolved oxygen (DO) conditions. Anaerobic zone was applied for phosphorus release prior to an aerated membrane bio-reactor (MBR), and anoxic zone was installed by placing a baffle in the MBR for enhancing denitrification even in high DO concentration in the MBR. Phosphorus removal was tested by alum coagulation in the anaerobic reactor preceding to MBR. DO concentration were 2.0, 1.5, 1.0, 0.75 mg/L in the MBR at different operating stages for finding optimum DO concentration in MBR for nitrogen removal by SND. pH was maintained at 7.0~8.0 without addition of alkaline solution even with alum addition due to high alkalinity in the raw sewage. Both TCODcr and $NH_4^+$-N removal efficiency were over 90% at all DO concentration. TN removal efficiencies were 50, 51, 54, 66% at DO concentration of 2.0, 1.5, 1.0, 0.75 mg/L, respectively. At DO concentration of 0.75 mg/L with addition of alum, TN removal efficiency decreased to 54%. TP removal efficiency increased from 29% to 95% by adding alum to anaerobic reactor. The period of chemical backwashing of the membrane module increased from 15~20 days to 40~50 days after addition of alum.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.179-185
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• 2005

Polycyclic aromatic hydrocarbons (PAHs) are a kind of toxic environmental pollutants and has been accumulated usually in marine sediments. Due to their potential hazardous to human, removal of PAHs from environments has been great concern. In the present study, the effect of microbial inoculation and the supplementation of mixed form cyclodextrin (M-CD) was assessed in the pre-sterilized or nonsterilized microcosms for optimizing operational conditions for ex situ bioremediation of sediments contaminated by PAHs. Activity of electron transport system (ETSA) was increased by the addition of M-CD regardless of inoculation of microorganisms in microcosms without sterilization. The degradation rate of PAHs in sterilized microcosms was app. 9-20% by the inoculation of single strain and 24-37% by the inoculation of microbial consortium supplemented with 1% M-CD, respectively. The degradation was not observed in microcosms without sterilization under the same conditions. The proportion of inoculated microorganisms also decreased in nonsterilized microcosms. Signals of inoculated bacteria were decreased to detection limit after 2 days in the microcosms without M-CD. In conclusion, microbial inoculation with appropriate carbon sources and removal of natural flora and grazers are required for the efficient ex situ bioremediation of sediments contaminated by PAHs in bioslurry reactor.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.321-330
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• 2008

본 연구는 흑운모 분말 급여시 육성돈에 생산성, 면역관련 혈액학적 지표, 혈청 내 스트레스 농도 및 분내 유해가스 발생에 미치는 영향을 구명하고자 실시하였다. 시험 동물은 [(Landrace ×Yorkshire)×Duroc] 3원 교잡종 육성돈 96두를 공시하였으며, 시험 개시시의 체중은 29.45±1.35kg으로 사양시험을 42일간 실시하였다. 시험설계에서 공시돈은 돈방당 4두씩 1) CON(Basal diet), 2) Solt2(Basal diet+Solto-B 0.2%), 3) Solt4(Basal diet+Solto-B 0.4%) 및 4) Solt6 (Basal diet+Solto-B 0.6%)로 4처리구에 각각 6돈방씩 완전 임의배치 하였다. 질소 소화율에서는 solt4 처리구가 CON과 solt2 처리구에 비해 유의적으로 높게 나타내었다(Linear effect = 0.016). 총 에너지에서는 Solt4와 Solt6 처리구가 CON 처리구에 비해 유의적으로 높게 나타내었다(Linear effect=0.008, Quadratic effect=0.019). 면역 및 스트레스 관련 혈액성상에서는 처리간의 차이가 없었다. 황화수소는 5 day와 10 day에서 대조구에 비해 Solt 처리구가 유의적으로 감소를 하였다(5 day, Linear effect=0.009, Quadractic effect=0.037; 10 day, Linear effect = 0.009). 아세트산는 5 day에서 대조구에 비해 Solt 처리구가 유의적으로 감소를 하였다(Linear effect <0.001, Quadractic effect < 0.001). 15 day에서도 CON과 Solt6 처리구가 Solt2와 Solt4 처리구에 비해 유의적으로 감소를 하였다(Quadractic effect=0.023). 메캅탄은 5 day와 10 day에서 CON 처리구에 비해 Solt 처리구가 유의적으로 감소를 하였다(5 day, Linear effec= 0.029, Quadractic effect=0.037; 10 day, Linear effect=0.029). 암모니아는 5 day, 10 day 및 15 day에서 Solt2와 Solt4 처리구가 CON과 Solt6 처리구에 비해 유의적으로 감소하였다(5 day, Quadractic effect=0.038; 10day, Quadractic effect = 0.045; 15day, Quadractic effect = 0.038). 결론적으로, 육성돈에 흑운모 분말 급여시 분내 유해가스 함량에 유의적인 감소를 나타내었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.276-276
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• 2010

Localized surface plasmon resonance (LSPR) has been explored recently as a promising approach to increase energy conversion efficiency in photovoltaic devices, particularly for thin film hydrogenated amorphous silicon (a-Si:H) solar cells. The LSPR is frequently excited via an electromagnetic (EM) radiation in proximate metallic nanostructures and its primary con sequences are selective photon extinction and local EM enhancement which gives rise to improved photogeneration of electron-hole (e-h) pairs, and consequently increases photocurrent. In this work, high-dielectric-constant (k) $ZrO_2$ (refractive index n=2.22, dielectric constant $\varepsilon=4.93$ at the wavelength of 550 nm) is proposed as spacing layer to enhance the LSPR for application to the thin film silicon solar cells. Compared to excitation of the LSPR using $SiO_2$ (n=1.46, $\varepsilon=2.13$ at the wavelength of 546.1 nm) spacing layer with Au nanoparticles of the radius of 45nm, that using $ZrO_2$ dielectric shows the advantages of(i) ~2.5 times greater polarizability, (ii) ~3.5 times larger scattering cross-section and ~1.5 times larger absorption cross-section, (iii) 4.5% higher transmission coefficient of the same thickness and (iv) 7.8% greater transmitted electric filed intensity at the same depth. All those results are calculated by Mie theory and Fresnel equations, and simulated by finite-difference time-domain (FDTD) calculations with proper boundary conditions. Red-shifting of the LSPR wavelength using high-k $ZrO_2$ dielectric is also observed according to location of the peak and this is consistent with the other's report. Finally, our experimental results show that variation of short-circuit current density ($J_{sc}$) of the LSPR enhanced a-Si:H solar cell by using the $ZrO_2$ spacing layer is 45.4% higher than that using the $SiO_2$ spacing layer, supporting our calculation and theory.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.396-401
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• 2007

This research investigated whether exposure of diesel exhaust particulate (DEP) and particulate metter (PM) effect on intercellular. adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression in asthma-induced Balb/c and IL-10 knock out (KO) mouse. Mouse was sensitized with intraperitoneal injection with ovalbumin, followed by challenges with intranasal ovalbumin. After induction of asthma mouse placed in the inhalation chamber and exposed to DEP and PM (10 $mg/m^3$). The evidences of pulmonary inflammation were assessed by immunohistochemical stain and westen blot against ICAM-1 and VCAM-1 in the lung tissue. In the immunohistochemical stain, positive reactions for ICAM-1 and VCAM-1 were much stronger in asthma-induced groups and asthma-induced group with DEP or PM than control groups. Although mild positive reactions were appeared in asthma-induced IL-10 KO mice groups, positive reactions were very strong in the asthma-induced group with DEP or PM. In Western blot, expression of VCAM-1 was increased in asthma-induced group with DEP or PM than asthma-induced groups. In the IL-10 KO mouse, ICAM-1 and VCAM-1 expression were increased in asthma-induced group with DEP or PM than asthma-induced groups. DEP and PM exposure have additive effects on the aggravation of inflammatory signs in the asthma-induced murine model. These results suggest that inhalation of DEP and PM in asthmatic patients may aggravate clinical symptoms.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.5.1-5.14
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• 2018

Oxidative stress-induced mitochondrial dysfunction is implicated in the pathogenesis of intervertebral disc degeneration (IVDD). Sirtuin 3 (SIRT3), a sirtuin family protein located in mitochondria, is essential for mitochondrial homeostasis; however, the role of SIRT3 in the process of IVDD has remained elusive. Here, we explored the expression of SIRT3 in IVDD in vivo and in vitro; we also explored the role of SIRT3 in senescence, apoptosis, and mitochondrial homeostasis under oxidative stress. We subsequently activated SIRT3 using honokiol to evaluate its therapeutic potential for IVDD. We assessed SIRT3 expression in degenerative nucleus pulposus (NP) tissues and oxidative stress-induced nucleus pulposus cells (NPCs). SIRT3 was knocked down by lentivirus and activated by honokiol to determine its role in oxidative stress-induced NPCs. The mechanism by which honokiol affected SIRT3 regulation was investigated in vitro, and the therapeutic potential of honokiol was assessed in vitro and in vivo. We found that the expression of SIRT3 decreased with IVDD, and SIRT3 knockdown reduced the tolerance of NPCs to oxidative stress. Honokiol ($10{\mu}M$) improved the viability of NPCs under oxidative stress and promoted their properties of anti-oxidation, mitochondrial dynamics and mitophagy in a SIRT3-dependent manner. Furthermore, honokiol activated SIRT3 through the AMPK-PGC-$1{\alpha}$ signaling pathway. Moreover, honokiol treatment ameliorated IVDD in rats. Our study indicated that SIRT3 is involved in IVDD and showed the potential of the SIRT3 agonist honokiol for the treatment of IVDD.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.13.1-13.15
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• 2018

Wound healing is delayed in diabetic patients. Increased apoptosis and endothelial progenitor cell (EPC) dysfunction are implicated in delayed diabetic wound healing. Melatonin, a major secretory product of the pineal gland, promotes diabetic wound healing; however, its mechanism of action remains unclear. Here, EPCs were isolated from the bone marrow of mice. Treatment of EPCs with melatonin alleviated advanced glycation end product (AGE)-induced apoptosis and cellular dysfunction. We further examined autophagy flux after melatonin treatment and found increased light chain 3 (LC3) and p62 protein levels in AGE-treated EPCs. However, lysosome-associated membrane protein 2 expression was decreased, indicating that autophagy flux was impaired in EPCs treated with AGEs. We then evaluated autophagy flux after melatonin treatment and found that melatonin increased the LC3 levels, but attenuated the accumulation of p62, suggesting a stimulatory effect of melatonin on autophagy flux. Blockage of autophagy flux by chloroquine partially abolished the protective effects of melatonin, indicating that autophagy flux is involved in the protective effects of melatonin. Furthermore, we found that the AMPK/mTOR signaling pathway is involved in autophagy flux stimulation by melatonin. An in vivo study also illustrated that melatonin treatment ameliorated impaired wound healing in a streptozotocin-induced diabetic wound healing model. Thus, our study shows that melatonin protects EPCs against apoptosis and dysfunction via autophagy flux stimulation and ameliorates impaired wound healing in vivo, providing insight into its mechanism of action in diabetic wound healing.

• Journal of Korean Philosophical Society
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• v.142
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• pp.265-294
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• 2017

In the early days of human history, the governing groups of rulers needed to justify their rule. The cause of rule became the ruling ideology. In China, the backbone of the ruling ideology was originally referred to as 'Di(帝)' or 'Shangdi(上帝)', who was later replaced by 'Tian(天)', Heaven. So there was a claim that Heaven gave the cause of the rule. This idea is the 'Tianming (天命)' idea. When the Zhou(周) Dynasty took control of the central government, the 'Tianming' idea had had a relatively sophisticated form. It was the 'Zhouli(周禮)' that organized the systematic order of the Zhou Dynasty. After this system collapsed, those who recognized 'Zhouli' as a desirable social system considered the collapse of 'Zhouli' as a situation of turbulent age. It was Qin(秦) State that unified all of the states of the period. However, after the unification, the Qin Dynasty fell sharply. The next dynasty was the Han(漢) Dynasty. The new ruling powers of the Han Dynasty needed to justify their regime. That means that it was necessary to establish the ruling ideology of the Han Dynasty. The representative of the ruling ideology of the Han Dynasty was Dongzhongshu, whose thought was based on Confucianism. His thought was related to "Chunqiugongyangzhuan(春秋公羊傳)", an interpretation of "Chunqiu(春秋)". This interpretation perspective is based on the idea of religious Heaven. Dongzhongshu thought that there were co-communions between Heaven and humans. His thought has the meaning of political theology in which rulers hold the basis of the rulers' sovereignty.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.685-697
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• 2019

The study aimed to analyze the structure of China's passenger railway network in the years of 2008, 2013, and 2018, respectively. At the same time, it tried to investigate its derivative impact on the patterns of Chinese urban network. The analytical tool was based on the NetMiner4.0. In order to measure network characteristics of China's passenger railway network, it primarily focused on the degree centrality, betweenness centrality, and closeness centrality. First of all, the higher degree centralities, with a few exceptions, were observed in BeiJing, ShangHai, GuangZhou, WuHan, XiAn, ChengDu, HaErBin, and ShenYang over a decade. In contrast, the higher betweenness centralities were recorded in cities of higher development potential including WuLuMuQi, GuiYang, ShenYang, and KunMing. The closeness centrality analyses confirmed the fact that most metropoles like BeiJing, ShangHai, and GuangZhou kept the highest train accessibility during the same research period. At the same time, the opening up of a new stretch of high speed railway network has consecutively strengthened connectivity between BeiJing and TianJin. Owing to unprecedented development of railway traffic and its extensive operations, this study believes that Chinese major cities, without interruption, would pursue a series of urban policy alternatives geared towards railway stations-oriented networking and competitively try to extend their network ranges.