• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.365-369
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• 2016

The 350[km/h] catenary system was successfully opened in Honam high speed line. This 350[km/h] catenary system is firstly constructed in South Korea. Therefore the current collection performance of this system should be tested and evaluated by the authority. This paper describes the testings by running of HEMU-430X train and the evaluation criteria and result analysis to determine whether the performance of the catenary is good or not as a verification of catenary-pantograph interface. In detail, the contact force by pantograph, arcs by loss of contact and uplift amount of the catenary support were measured and discussed as a category of the current collection performance.

• Journal of the Optical Society of Korea
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• v.12 no.4
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• pp.303-308
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• 2008

Directly modulated fiber-optic links generally suffer higher link loss and larger signal distortion than externally modulated links. These result from the electron-photon conversion loss and laser modulation dynamics. As a method to overcome the drawbacks, we have experimentally demonstrated the RF performance of directly modulated, ultra-strong injection-locked gain-lever distributed Bragg reflector (DBR) lasers. The free-running DBR lasers exhibit an improved amplitude modulation efficiency of 12.4 dB under gain-lever modulation at the expense of linearity. By combining gain-lever modulation with ultra-strong optical injection locking, we can gain the benefits of both improved modulation efficiency from the gain-lever effect, plus improved linearity from injection locking. Using an injection ratio of R=11 dB, a 23.4-dB improvement in amplitude response and an 18-dB improvement in spurious-free dynamic range have been achieved.

• Journal of Animal Environmental Science
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• v.8 no.2
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• pp.119-124
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• 2002

To evaluate composting process of piggery slurry, we made $1m^3$ bench scale composting reactor, and investigated the input and output of mass, moisture evaporation, volatile solid degradation, and running cost. For 15 days experimentation the results was as followed, The quantity of sawdust used was 0.47ton(18,000won) per 1ton slurry. The amount of moisture evaporated was 16.8kg/kg VS degradated. Total evaporation and VS degradation were 24.8%, 5.7% respectably. To analysis the running cost of that, we included only two factors, sawdust cost and compost income. The compost price to sell was 63won/kg(50% of market price) it made 8,694won income to 756 won loss, but 25won/kg, it was $13,650{\sim}23,100won$ loss per 1 ton slurry in the current pig farmer's condition. This cost was $8.5{\sim}14.4%$ of pig production cost and damage strongly to pig farmers to treat it.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.10-12
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• 2009

Electromagnetic Interference(EMI) in electric railway operation has become increasingly important. The components within very high power electronic, and the circuits for treating low-level signals, comprise complex system that must coexist and be highly reliable. To study it, It were included how much the HEMU-400X generates EMI and it has an effect on the power conversion units which resulted from Power Line Disturbance (PLD) phenomenon by contact loss during its running. In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

• Smart Structures and Systems
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• v.14 no.4
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• pp.617-641
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• 2014

The energy constraint is still a common issue for the practical application of wireless sensors, since they are usually powered by batteries which limit their lifetime. In this paper, a practical compound energy efficiency strategy is proposed and realized in the implementation of a real time wireless sensor platform. The platform is intended for wireless structural monitoring applications and consists of three parts, wireless sensing unit, base station and data acquisition and configuration software running in a computer within the Matlab environment. The high energy efficiency of the wireless sensor platform is achieved by a proposed adaptive radio transmission power control algorithm, and some straightforward methods, including adopting low power ICs and high efficient power management circuits, low duty cycle radio polling and switching off radio between two adjacent data packets' transmission. The adaptive transmission power control algorithm is based on the statistical average of the path loss estimations using a moving average filter. The algorithm is implemented in the wireless node and relies on the received signal strength feedback piggybacked in the ACK packet from the base station node to estimate the path loss. Therefore, it does not need any control packet overheads. Several experiments are carried out to investigate the link quality of radio channels, validate and evaluate the proposed adaptive transmission power control algorithm, including static and dynamic experiments.

• The Journal of Internal Korean Medicine
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• v.45 no.1
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• pp.11-30
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• 2024

Objectives: This study evaluated the effects of Ssanghwa-tang (SHT) on lung injury and muscle loss in a COPD mouse model. Methods: C57BL/6 mice were challenged with cigarette smoke extract and lipopolysaccharide, and then treated with two concentrations of SHT (250 and 500 mg/kg). After sacrifice, the bronchoalveolar lavage fluid (BALF) or lung tissue was analyzed by cytospin, ELISA, real-time PCR, flow cytometry analysis, and H&E and Masson's trichrome staining. The grip strength of COPD mice was measured using a grip strength meter. The running time of COPD mice was measured by a treadmill test. Muscle tissue of the quadriceps was stained with H&E and Masson's trichrome staining. Results: SHT significantly inhibited the increase in neutrophil numbers in BALF and significantly decreased immune cell activity in BALF and lung tissue. It also significantly inhibited the increase in TNF-α, IL-17, and MIP2 in BALF. Real-time PCR analysis revealed that the mRNA expression of TNF-α, IL-17, MIP2, and TRPV1 in lung tissue showed a significant decrease compared with the control group. Lung tissue damage was significantly reduced in the histological analysis. The grip strength and running time of the COPD mice showed a significant decrease compared with the control group. In histological staining, SHT was found to reduce the damage to muscle tissue. Conclusions: This study indicates that SHT can be used as a therapeutic agent for COPD patients by inhibiting lung injury and muscle loss.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.1
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• pp.5-10
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• 1997

Because of environmental pollution and reserve limitations of fossil fuels, several alternative energies have been developing. One of them, the hydrogen is researched as a highly probable solution. In this study pure hydrogen gas and oxygen gas are burned in combustor to reduce the emission, and a gas turbine is used. Cooling water around the combustor recovers the cooling heat loss to useful work by being expanded from liquid to vapor, being injected into the combustor and making pressure rise with working fluid to get more turbine power. Because pure hydrogen and oxygen are used, there is no carbonic emission such as CO, $CO_2$, HC nor $NO_x$, and $SO_x$. The power is obtained by turbine system, which makes lower noise and vibration than any reciprocating engine. Running of a turbine is searched under various conditions of hydrogen flow rate and water injection rate. Maximum speed of the turbine is obtained when the combustion reaches steady state. It is enable to determine the optimum rate between hydrogen flow and water injection which makes turbine run maximum speed.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.8
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• pp.730-740
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• 2000

The software rejuvenation method for highly available multiplex systems uses a pro-active fault-tolerant approach to handle system failures. The software rejuvenation prevents failures from occurring, while the previous methods recover from failures after happening. Especially, since the software aging proceeds fast in the software used for the multimedia mobile computing due to the loss of communications or data, the preventive method from failures using software rejuvenation can be used for the multimedia mobile computing. In this paper, according to the operational parameters such as rejuvenation period, rejuvenation time, failure rate and repair rate of the servers, number of running servers, duration of running time, and type of running modes, we calculate steady-state probabilities, downtime, availability, and cost of the multiplex systems using software rejuvenation method. We validate the closed-form solutions of the mathematical model by experiments based on various operational parameters and find that the software rejuvenation method can be adopted as preventive fault-tolerant technique. The failure rate and unstable rate of the servers are essential factors for the decision making of the rejuvenation policies.

• Molecules and Cells
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• v.42 no.4
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• pp.301-312
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• 2019

Post-transcriptional regulation underlies the circadian control of gene expression and animal behaviors. However, the role of mRNA surveillance via the nonsense-mediated mRNA decay (NMD) pathway in circadian rhythms remains elusive. Here, we report that Drosophila NMD pathway acts in a subset of circadian pacemaker neurons to maintain robust 24 h rhythms of free-running locomotor activity. RNA interference-mediated depletion of key NMD factors in timeless-expressing clock cells decreased the amplitude of circadian locomotor behaviors. Transgenic manipulation of the NMD pathway in clock neurons expressing a neuropeptide PIGMENT-DISPERSING FACTOR (PDF) was sufficient to dampen or lengthen free-running locomotor rhythms. Confocal imaging of a transgenic NMD reporter revealed that arrhythmic Clock mutants exhibited stronger NMD activity in PDF-expressing neurons than wild-type. We further found that hypomorphic mutations in Suppressor with morphogenetic effect on genitalia 5 (Smg5) or Smg6 impaired circadian behaviors. These NMD mutants normally developed PDF-expressing clock neurons and displayed daily oscillations in the transcript levels of core clock genes. By contrast, the loss of Smg5 or Smg6 function affected the relative transcript levels of cAMP response element-binding protein B (CrebB) in an isoform-specific manner. Moreover, the overexpression of a transcriptional repressor form of CrebB rescued free-running locomotor rhythms in Smg5-depleted flies. These data demonstrate that CrebB is a rate-limiting substrate of the genetic NMD pathway important for the behavioral output of circadian clocks in Drosophila.

• Journal of Periodontal and Implant Science
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• v.41 no.6
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• pp.279-284
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• 2011

Purpose: To describe the profile of chronic and aggressive periodontitis among Senegalese (West Africans) attending the Institute of Dentistry of Dakar. Methods: A retrospective study was conducted with an inclusion period running from 2001 to 2008. The sample included 413 chronic periodontitis and 151 aggressive periodontitis cases, among them 299 males and 265 females selected from 2,274 records. A Student's independent t-test or Pearson chi-squared test was used for data analysis. Results: The proportion of females with aggressive periodontitis was significantly higher than those with chronic periodontitis (64.9% vs. 40.4%, P<0.001). The aggressive periodontitis patients had an average age of $28.1{\pm}8.9$ years, and had lost less than 3 teeth. Less than a third of them reported using a toothbrush. Attachment loss was as high as 8 mm and severe lesions had spread to an average of 12 teeth with maximum alveolar bone loss up to 80%. The chronic periodontitis patients had an average age of $44.9{\pm}14.0$ and had lost on average less than 3 teeth. Nearly 75% used a toothbrush. Attachment loss was significantly higher and lesions were more extensive in the aggressive periodontitis. Chronic periodontitis is associated with risk factors such as smoking or diabetes mellitus in 12.8% versus 0.7% in aggressive periodontitis (P<0.001). Differences between the two groups for most clinical and radiographic parameters were statistically significant. Conclusions: The profile of aggressive periodontist is characterized by more severe lesions than chronic periodontitis, whereas tooth loss experience is similar in both forms.