• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.437-441
• /
• 2006

Wireless sensor network consists of sensor nodes which are disseminated closely to each other to collect informations for the various requests of a sensor application applied for sensing phenomenons in real world. Each sensor node delivers sensing informations to an end user by conducting cooperative works such as processing and communicating between sensor nodes. In general, the power supply of a sensor node is depends on a battery so that the power consumption of a sensor node decides the entire life time of a sensor network. To resolve the problem, optimal routing algorithm can be used for prolong the entire life time of a sensor network based on the information on the energy level of each sensor node. In this paper, different from the existing Directed Diffusion and SPTN method, we presents a data dissemination protocol based on lower-power consumption that effectively maximizes the whole life time of a sensor network using the informations on the energy level of a sensor node and shortest-path hops. With the proposed method, a data transfer path is established using the informations on the energy levels and hops, and the collected sensing information from neighboring nodes in the event-occurring area is merged with others and delivered to users through the shortest path.

• Journal of Korean Academy of Nursing
• /
• v.39 no.5
• /
• pp.683-692
• /
• 2009

Purpose: The purpose of this study was to identify cancer-related symptom clusters and to validate the conceptual meanings of the revealed symptom clusters in patients with hepatocellular carcinoma. Methods: This study was a cross-sectional survey and methodological study. Patients with hepatocellular carcinoma (N=194) were recruited from a medical center in Seoul. The 20-item Symptom Checklist was used to assess patients' symptom severity. Selected symptoms were factored using principal-axis factoring with varimax rotation. To validate the revealed symptom clusters, the statistical differences were analyzed by status of patients' performance status, Child-Pugh classification, and mood state among symptom clusters. Results: Fatigue was the most prevalent symptom (97.4%), followed by lack of energy and stomach discomfort. Patients' symptom severity ratings fit a four-factor solution that explained 61.04% of the variance. These four factors were named pain-appetite cluster, fatigue cluster, itching-constipation cluster, and gastrointestinal cluster. The revealed symptom clusters were significantly different for patient performance status (ECOG-PSR), Child-Pugh class, anxiety, and depression. Conclusion: Knowing these symptom clusters may help nurses to understand reasonable mechanisms for the aggregation of symptoms. Efficient symptom management of disease-related and treatment-related symptoms is critical in promoting physical and emotional status in patients with hepatocellular carcinoma.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.2
• /
• pp.380-388
• /
• 2002

The inhibitory effects of the traditional herbal medicine Hwao-tang on the progression of the atherosclerotic lesions were studied using the spontaneous familial hypercholesterolemia (FH) model, Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. Hwao-tang is activate blood circulation, vital energy and regulate menstruation, etc. Nowadays, Hwao-tang is mainly used for the treatment of inflammation, hyperlipemia and arteriosclerosis. However, pharmacological mechanisms of Hwao-tang on lipid metabolism and atherosclerosis formation are poorly understood. We have investigated the pharmacological effects of Hwao-tang on hypercholesterolemia and atherosclerosis using a spontaneous experimental model. In conclusion, the protection of extracts of HOT and its herbs on the ischemic infarction induced artificially might be related to their inhibitory effects on DIC, platelet coagulation and thrombic action. These suggest that Hwao-tang has inhibitory effects on the development of atheromatous plaque formation in spontaneous FH model rabbits. It is possible that the anti oxidative effects of Hwao-tang on LDL led to the beneficial effects observed in this study.

• Journal of Nutrition and Health
• /
• v.28 no.9
• /
• pp.862-871
• /
• 1995

This study was designed to investigate the effectiveness of ginseng intakes in modifying serum lipid profiles and plasma clotting factors. The participants in this study were 47 normal healthy volunteers(men 24, women 23) with an age range of 35-49 years and a mean age of 41 years residing in Taejon. Based on the diet intakes, subjects were classed into one of three groups : control, vegetarian, and ginseng consumed over 3-4 years. There was no significant difference in their physical characteristics. Dietary calorie intakes were not significantly different in subjects. The ratio of energy intake in the control and ginseng consumed group was 63-64% : 20-21% : 15-16%(Cho : Fat : Pro), but 70-73% : 13-14% :14-15%(Cho : Fat : Pro) in the vegetarians. The intakes of animal food in the vegetarian was significantly lower than the control and ginseng consumed group in men. The ratio of P/S(1.27) was the highest in the vegetarians. Venous blood samples were taken for serum lipid profiling, plasma clotting assay and platelet function. The concentration of serum triglyceride in the men ginseng group is significantly lower than those of the men control group. Serum lipid profiles values of the men ginseng group, such as total cholesterol and phospholipid were lower those of the men control group, but higher those of the men vegetarian group. the serum lipid profile in the women were not significant, but total cholesterol, triglyceride and LDL cholesterol levels in the ginseng groups were low. The concentration of HDL cholesterol was not significantly different. Platelet cell count and platelet aggregation were low in the ginseng groups. APTT(Activated Partial thromboplastin time) was significantly elongated in ginseng groups in the normal range. In seems that the major beneficial effects of ginseng intakes in especially men were on the blood concentrations of triglyceride, total cholesterol and elongation of plasma clotting time.

• Journal of KIISE:Computing Practices and Letters
• /
• v.15 no.3
• /
• pp.201-205
• /
• 2009

This paper addresses issues to efficiently collect and aggregate data of sources within a local and adjacent region in geographic routing for wireless sensor networks. We first introduce the concept of a local sink which collects and aggregates data form source nodes in the region and delivers the aggregated data to a global sink. We also design a model to determine an optimal location of the local sink and propose a mechanism to collect data through the local sink. Simulation results show that the proposed mechanism with the local sink is more efficient in terms of the energy and the data delivery ratio than the existing mechanism without the local sink in a geographic routing.

• BMB Reports
• /
• v.43 no.3
• /
• pp.176-181
• /
• 2010

The primary sigma factor ($\sigma^{A}$) of Staphylococcus aureus, a potential drug target, was little investigated at the structural level. Using an N-terminal histidine-tagged $\sigma^{A}$ (His-$\sigma^{A}$), here we have demonstrated that it exits as a monomer in solution, possesses multiple domains, harbors primarily $\alpha$-helix and efficiently binds to a S. aureus promoter DNA in the presence of core RNA polymerase. While both N- and C-terminal ends of His-$\sigma^{A}$ are flexible in nature, two Trp residues in its DNA binding region are buried. Upon increasing the incubation temperature from 25$^{\circ}$ to 40$^{\circ}C$, $\sim$60% of the input His-$\sigma^{A}$ was cleaved by thermolysin. Aggregation of His-$\sigma^{A}$ was also initiated rapidly at 45$^{\circ}C$. From the equilibrium unfolding experiment, the Gibbs free energy of stabilization of His-$\sigma^{A}$ was estimated to be +0.70 kcal $mol^{-1}$. The data together suggest that primary sigma factor of S. aureus is an unstable protein. Core RNA polymerase however stabilized $\sigma^{A}$ appreciably.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.3
• /
• pp.276-280
• /
• 2016

This study investigated luring distributions by water layer of common squid which were targeted by angling fishing vessels equipped with LED and metal-halide lamps using a scientific echosounder with a 120 kHz frequency in order to develop energy-effective underwater fish aggregation devices. In the analysis, angles of a transducer were changed from $0^{\circ}$ to $45^{\circ}$ and were rotated every $10^{\circ}$ horizontally. It was shown that common squid were densely distributed from the surface to 40 m and they were also distributed in directions of $10^{\circ}{\sim}+30^{\circ}$, $-30^{\circ}{\sim}-60^{\circ}$, and $-120^{\circ}{\sim}-130^{\circ}$with the head of vessel as the center. Comparative results of angles of transducer on acoustical densities of common squid distributing in 21~40 m water depth showed an average $101.8m^2/nm^2$ in vertical direction of $0^{\circ}$, $12.3m^2/nm^2$ in angle of $30^{\circ}$, and $42.4m^2/nm^2$ in angle of $45^{\circ}$, respectively. It implied that more considerations on acoustic scattering strength by incidence angle direction of the transducer and swimming oriental angle direction of common squid would be required.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.10
• /
• pp.3052-3058
• /
• 2014

In this article, we have designed and synthesized a novel donor-${\pi}$-acceptor (D-${\pi}$-A) type porphyrin-based sensitizer (denoted UI-5), in which a carboxyl anchoring group and a 9,9-dimethyl fluorene were introduced at the meso-positions of porphyrin ring via phenylethynyl and ethynyl bridging units, respectively. Long alkoxy chains in ortho-positions of the phenyls were supposed to reduce the degree of dye aggregation, which tends to affect electron injection yield in a photovoltaic cell. The cyclic voltammetry was employed to determine the band gap of UI-5 to be 1.41 eV based on the HOMO and LUMO energy levels, which were estimated by the onset oxidation and reduction potentials. The incident monochromatic photon-to-current conversion efficiency of the UI-5 DSSC assembled with double-layer (20 nm-sized $TiO_2$/400 nm-sized $TiO_2$) film electrodes appeared lower upon overall ranges of the excitation wavelengths, but exhibited a higher value over the NIR ranges (${\lambda}$ = 650-700 nm) compared to the common reference sensitizer N719. The UI-5-sensitized cell yielded a relatively poor device performance with an overall conversion efficiency of 0.74% with a short circuit photocurrent density of $3.05mA/cm^2$, an open circuit voltage of 0.54 mV and a fill factor of 0.44 under the standard global air mass (AM 1.5) solar conditions. However, our report about the synthesis and the photovoltaic characteristics of a porphyrin-based sensitizer in a D-${\pi}$-A structure demonstrated a significant complex relationship between the sensitizer structure and the cell performance.

• Korean Journal of Materials Research
• /
• v.17 no.9
• /
• pp.453-457
• /
• 2007

Interest in use of ink-jet printing for pattern-on-demand fabrication of metal interconnects without complicated and wasteful etching process has been on rapid increase. However, ink-jet printing is a wet process and needs an additional thermal treatment such as an annealing process. Since a metal ink is a suspension containing metal nanoparticles and organic capping molecules to prevent aggregation of them, the microstructure of an ink-jet printed metal interconnect 'as dried' can be characterized as a stack of loosely packed nanoparticles. Therefore, during being treated thermally, an inkjet-printed interconnect is likely to evolve a characteristic microstructure, different from that of the conventionally vacuum-deposited metal films. Microstructure characteristics can significantly affect the corresponding electrical and mechanical properties. The characteristics of change in microstructure and electrical resistivity of inkjet-printed silver (Ag) films when annealed isothermally at a temperature between 170 and $240^{\circ}C$ were analyzed. The change in electrical resistivity was described using the first-order exponential decay kinetics. The corresponding activation energy of 0.44 eV was explained in terms of a thermally-activated mechanism, i.e., migration of point defects such as vacancy-oxygen pairs, rather than microstructure evolution such as grain growth or change in porosity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.571-573
• /
• 2018

Wireless sensor networks have unbalanced energy consumption due to the convergence structure in which data is concentrated to sink nodes. To solve this problem, in the previous research, the relay node was placed between the source node and the sink node to merge the data before being concentrated to the sink node. However, selecting a relay node that does not consider the link quality causes packet loss according to the link quality of the reconfigured routing path. Therefore, in this paper, we propose a link cost calculation method for data reliability in routing path reconfiguration for relay node selection. We propose a link cost estimation formula considering the number of hops and RSSI as the routing metric value and select the RSSI threshold value through the packet transmission experiment between the sensor modules.