• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.195-200
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• 1993

The neutral, reduced, and oxidized 2,2-trans isomers of $Rh_2(ap)_4$ (ap=2-anilinopyridinate) were investigated with respect to dioxygen binding in $CH_2Cl_2$ containing 0.1 M tetrabutyl-ammonium perchlorate. $Rh_2(ap)_4$ binds dioxygen in nonaqueous media and forms a $Rh^{II}Rh^{III}$ superoxide complex, $Rh_2(ap)_4(O_2)$. This neutral species was isolated and is characterized by UV-visible and IR spectroscopy, mass spectrometry and cyclic voltammetry. It can be reduced by one electron at $E_{1/2}$ = -0.45 V vs. SCE in $CH_2Cl_2$ and gives ${[Rh_2(ap)_4(O_2)]}^-$ as demonstrated by the ESR spectrum of a frozen solution taken after controlled potential reduction. The superoxide ion in ${[Rh_2(ap)_4(O_2)]}^-$ is axially bound to one of the two rhodium ions, both of which are in a +2 oxidation state. $Rh_2(ap)_4(O_2)$ can also be stepwise oxidized in two one-electron transfer steps at $E_{1/2}$ = 0.21 V and 0.85 V vs. SCE in $CH_2Cl_2$ and gives ${[Rh_2(ap)_4(O_2)]}^+$ followed by ${[Rh_2(ap)_4(O_2)]}^{2+}$. ESR spectra demonstrate that the singly oxidized complex is best described as ${[Rh^{II}Rh^{III}(ap)_4(O_2)]}^+$ where the odd electron is delocalized on both of the two rhodium ions and the axial ligand is molecular oxygen.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.221-232
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• 2016

Models to estimate solar radiation have been used because solar radiation is measured at a smaller number of weather stations than other variables including temperature and rainfall. For example, solar radiation has been estimated using the Angstrom-Prescott (AP) model that depends on two coefficients obtained empirically at a specific site ($AP_{Choi}$) or for a climate zone ($AP_{Frere}$). The objective of this study was to identify the coefficients of the AP model for reliable estimation of solar radiation under a wide range of spatial and temporal conditions. A global optimization was performed for a range of AP coefficients to identify the values of $AP_{max}$ that resulted in the greatest degree of agreement at each of 20 sites for a given month during 30 years. The degree of agreement was assessed using the value of Concordance Correlation Coefficient (CCC). When $AP_{Frere}$ was used to estimate solar radiation, the values of CCC were relatively high for conditions under which crop growth simulation would be performed, e.g., at rural sites during summer. The statistics for $AP_{Frere}$ were greater than those for $AP_{Choi}$ although $AP_{Frere}$ had the smaller statistics than $AP_{max}$ did. The variation of CCC values was small over a wide range of AP coefficients when those statistics were summarized by site. $AP_{Frere}$ was included in each range of AP coefficients that resulted in reasonable accuracy of solar radiation estimates by site, year, and month. These results suggested that $AP_{Frere}$ would be useful to provide estimates of solar radiation as an input to crop models in Korea. Further studies would be merited to examine feasibility of using $AP_{Frere}$ to obtain gridded estimates of solar radiation at a high spatial resolution under a complex terrain in Korea.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.11-20
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• 2014

For Web-based applications in IoT environment, IETF CoRE WG has standardizing the CoAP. One of limitations of CoAP is that CoAP standard does not consider the mobility management of the CoAP sensor node. In this paper, we propose the mobility management protocol of CoAP sensor node by considering the characteristics of the constrained network. The proposed mobility management protocol supports for Web client to be transmitted the sensing data from CoAP node reliably while the CoAP sensor moves into different wireless networks. To do this, we designed the architecture with the separate IP address management of CoAP sensor node and presented the mobility management protocol, which includes the holding and binding mode, in order to provide the reliable transmission. Finally, the numerical analysis and simulation with NS2 tool have been done for the performance evaluation in terms of the handover latency and packet loss with comparing the proposed mobility management protocol with other the existing mobility management protocols. The performance result shows that the proposed mobility management can provide the transmission of sensing data without the packet loss comparing with the existing mobility management protocol reliably.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.818-825
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• 2013

We isolated and functionally characterized the ${\alpha}$- and ${\beta}$-subunits (ApCpnA and ApCpnB) of a chaperonin from Aeropyrum pernix K1. The constructed vectors pET3d-ApCpnA and pET21a-ApCpnB were transformed into E. coli Rosetta (DE3), BL21 (DE3), or CodonPlus (DE3) cells. The expression of ApCpnA (60.7 kDa) and ApCpnB (61.2 kDa) was confirmed by SDS-PAGE analysis. Recombinant ApCpnA and ApCpnB were purified by heat-shock treatment and anion-exchange chromatography. ApCpnA and ApCpnB were able to hydrolyze not only ATP, but also CTP, GTP, and UTP, albeit with different efficacies. Purified ApCpnA and ApCpnB showed the highest ATPase, CTPase, UTPase, and GTPase activities at $80^{\circ}C$. Furthermore, the addition of ApCpnA and ApCpnB effectively protected citrate synthase (CS) and alcohol dehydrogenase (ADH) from thermal aggregation and inactivation at $43^{\circ}C$ and $50^{\circ}C$, respectively. In particular, the addition of ATP or CTP to ApCpnA and ApCpnB resulted in the most effective prevention of thermal aggregation and inactivation of CS and ADH. The ATPase activity of the two chaperonin subunits was dependent on the salt concentration. Among the ions we examined, potassium ions were the most effective at enhancing the ATP hydrolysis activity of ApCpnA and ApCpnB.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.2
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• pp.177-188
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• 2006

In this paper, we define and study the vector-valued ap-Henstock-Stieltjes integral, we prove the Cauchy extension theorem and the dominated convergence theorems for the ap-Henstock-Stieltjes integral.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.9
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• pp.1-11
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• 2002

The optimal AP placement for wireless LAN is important factor for improving service quality and reducing cost. Decision of AP placement is depend on radio signal strength, environment factor and logical area property, which is user's frequently posed place. This paper proposes optimal multiple AP placement method based on radio prediction tool. The proposed method can get flexibility in multiple AP placement using user defined parameter and the optimization design uses Hopfield network algorithm. And path-loss model is used for one of radion prediction model. The result of simulation shows that it is efficiently reduces the process to find optimal AP placement. And the proposed optimization design of multiple AP placement can improve service quality for wireless LAN.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.147-153
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• 2016

Recently, IETF (Internet Engineering Task) working group has adopted CoAP (Constrained Application Protocol) as a standard IoT proctocol. CoAP is a specialized web transfer protocol for use with constrained nodes and constrained environment such as small memory and low power networks. In this paper, we design and implement a registration service with CoAP protocol based on RD(Resource Directory) to connect IoT nodes in mobile Internet environments. The resource directory between the mobile terminal and IoT nodes provides to discover the IoT nodes and get the context data. The mobile terminal has as the CoAP client and embedded IoT nodes includes as the CoAP server so that it can conveniently manage the constrained IoT nodes to get the context data and control devices in a mobile environments.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.150-160
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• 2014

Greenhouse gas (GHG) and Air Pollution (AP) emission inventories have been constructed and estimated independently up-to-date in Seoul. It causes difficulty in GHG and AP integrated management due to a difference in emission inventories. In this study, we constructed GHG and AP integrated emission inventories for direct and indirect sources in Seoul during the year 2010 in Energy activities for estimating GHG and AP emissions were derived from IPCC guideline, guidelines for local government greenhouse inventories, air pollutants calculation manual, and Indirect Emission Factors (IEF) reported by Korea Power Exchange. The annual GHG emission was estimated as 50,530,566 $tonCO_{2eq}$, of which 54.8% resulted from direct sources and the remaining 45.2% from indirect sources. Among direct sources, transportation sector emitted the largest GHG, accounting for 47.3% of the total emission from direct sources. As with indirect sources, purchased electricity sector only emitted 98.6% of the total emission from indirect sources. The annual AP emission was estimated as 283,701 tonAP, of which 85.9% was contributed by the combined AP emissions of transportation and fugitive sectors. Estimation of individual air pollutant showed that the largest source were transportation sector for CO, $NO_x$, TSP, $PM_{10}$ and NH3, non-energy sector for $SO_x$, and fugitive sector for VOCs. This study found some limitations in estimating GHG and AP integrated emissions, such as nonconforming emission inventories between GHG and AP, and no indirect AP emission factor of purchased electricity, and so on. Those should be further studied and improved for more effective GHG and AP integrated management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.411-413
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• 2010

The wireless AP positioning system is under active progress regarding research and commercialization due to its merit of being able to overcome the representing demerits of existing GPS positioning, which are signal distortion and poor signal reception. This system's feature is to collect AP information distributed throughout the real world, store it on database, and execute positioning by comparing with searched AP information. The positioning process uses collected data, whereas comparison of database data uses the fingerprinting method. The fingerprinting method is a probabilistic modeling method that acquires as much of the data collected from one location upon database composition, to store the value's average value and use it in positioning. Yet, using the average value may contain the probability of errors. Such errors are fatal weaknesses for services based on the background of accurate positioning. This paper deals with the characteristics and problems of the previously used wireless AP positioning system, and proposes measures of using AP information for outdoor positioning in order to solve the aforementioned problems.

• The Korea Journal of Herbology
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• v.28 no.3
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• pp.95-106
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• 2013

Objectives : The researcher investigated the anti-obesity effect of Alismatis Orientale Rhizoma(AP) water extract in mice fed a high fat diet and focused on the analysis of local area adipose tissue. Methods : Male ICR mice were divided into three groups, which were fed either a normal AIN diet, a 45% high fat diet (CT group), or a high fat diet and orally administration with a concentrations of 100 mg/kg (AP100 group) and 300 mg/kg body weight (AP300 group) for eight weeks. Results : As compared with CT group, AP100 group showed significant reductions in absolute weight of liver. As compared with CT group, AP100 group and AP300 group showed significant reductions in weight gain and relative weight of total fat. AST, triglyceride, total-cholesterol levels from the AP 100 group and 300 group were significantly lower than those of the CT, and ALT, LDL-cholesterol levels from the AP 100 group was significantly lower than those of the CT. But serum HDL-cholesterol levels from the AP 100 group and 300 group were significantly higher than those of the CT. And serum adiponectin levels from the AP 100 group was significantly higher than those of the CT. In result of real time PCR, all mRNA expression(PEPCK, G6Pase, PGC-$1{\alpha}$ and $ERR{\gamma}$) of two experimental groups were significantly decreased compared to those of CT group. The treatment with AP on local abdominal area made a fat cell size lessen on the fat tissue in the abdominal cavity and subcutaneous area. Conclusions : These results suggest that AP has an anti-obesity effect and the effect is mediated by inhibition of fat gain.