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Energy & Environmental Materials 2024年第2期7卷 83-92页

作者： Hak Hyeon lee Dong Su Kim Swagotom Sarker Ji Hoon Choi Ho Seong lee hyung Koun Cho Department of Advanced Materials Science&Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-doSeoul 16419Korea Department of Advanced Materials Science&Engineering Kyungpook National University80Daehak-roBuk-guDaegu 41566Korea

Rh has been widely studied as a catalyst for the promising hydrazine oxidation reaction that can replace oxygen evolution reactions for boosting hydrogen production from hydrazine-containing *** Rh being expensive,only a few studies have examined its electrocatalytic mass ***,surface-limited cation exchange and electrochemical activation processes are designed to remarkably enhance the mass activity of *** atoms were readily replaced at the Ni sites on the surface of NiOOH electrodes by cation exchange,and the resulting RhOOH compounds were activated by the electrochemical reduction *** cation exchange-derived Rh catalysts exhibited particle sizes not exceeding 2 nm without agglomeration,indicating a decrease in the number of inactive inner Rh ***,an improved mass activity of 30 A mg_(Rh)^(-1)was achieved at 0.4 V versus reversible hydrogen ***,the two-electrode system employing the same CE-derived Rh electrodes achieved overall hydrazine splitting over 36 h at a stable low *** proposed surface-limited CE process is an effective method for reducing inactive atoms of expensive noble metal catalysts.

关键词： cation exchange synthesis electrochemical metallization hydrazine oxidation reaction mass activity rhodium catalyst

Inter-observer Reliability of Indicators and Decision of Pattern Identification Using Diagnostic Flowchart with Traditional Korean Medicine

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Chinese Journal of Integrative Medicine 2017年第5期23卷 338-344页

作者： ju Ah lee Jeeyoun jung Mi Mi Ko Myeong Soo lee Korean Medicine Fundamental Research Division Korea Institute of Oriental Medicine Daejeon 305-811 Republic of Korea Clinical Research Division Korea Institute of Oriental Medicine Daejeon 305-811 Republic of Korea

Objective： To evaluate the consistency of patterns and pattern identification（PI）, and the improvement in the diagnosis of blood stasis after the standard operating procedures（SOPs） were enhanced by using a diagnostic flowchart. Methods： A total of 358 subjects who were admitted by the Jaseng Hospital of Korean Medicine between june 2013 and December 2014 were included in the study. Each patient was independently diagnosed by two experts from the same department. In 2014, the SOPs included the use of a diagnostic flowchart for each indicator. Inter-observer consistency was assessed by simple percent agreement and by the kappa and AC1 statistics. Results： The improvements in inter-observer agreement for the indicators（for al patients） and PI were greater in 2014 than in 2013. In 2013, the j-value measure of agreement between the two experts ranged from ＂poor＂（κ=–0.051） to ＂good＂（κ=0.968）. The AC1 measure of agreement between the experts was generally high for the indicators and ranged from –0.010 to 0.978. In most cases, agreement was considerably lower when it was assessed by the j-values compared with the AC1 values. In 2014, the j-value measure of agreement on the indicators（for the subjects） general y ranged from poor to good, with the values ranging from –0.007 to 0.994. Moreover, the AC1 measure of agreement between the experts was general y high for al of the indicators and ranged from ＂moderate＂（AC1=0.408） to ＂excel ent＂（AC1=0.996）. Conclusions： In four examinations, there was moderate agreement between the clinicians on the PI indicators of blood stasis. To improve clinician consistency（e.g., in the diagnostic criteria used）, it is necessary to analyse the reasons for inconsistency and to improve clinician training.（Trial registration No. KCT0000916）

关键词： blood stasis inter-observer reliability pattern identification traditional Chinese medicine traditional Korean medicine

Application of signal processing techniques to the detection of tip vortex cavitation noise in marine propeller

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Journal of Hydrodynamics 2013年第3期25卷 440-449页

作者： lee Jeung-Hoon HAN Jae-Moon PARK hyung-Gil SEO Jong-Soo Samsung Ship Model Basin (SSMB) Marine Research Institute Samsung Heavy Industries Science TownDaejeon 305-380 Korea

The tip vortex cavitation and its relevant noise has been the subject of extensive researches up to now. In most cases of experimental approaches, the accurate and objective decision of cavitation inception is primary, which is the main topic of this paper. Although the conventional power spectrum is normally adopted as a signal processing tool for the analysis of cavitation noise, a faithful exploration cannot be made especially for the cavitation inception. Alternatively, the periodic occurrence of bursting noise induced from tip vortex cavitation gives a diagnostic proof that the repeating frequency of the bursting contents can be exploited as an indication of the inception. This study, hence, employed the Short-Time Fourier Transform （STFT） analysis and the Detection of Envelope Modulation On Noise （DEMON） specmma analysis, both which are appropriate for finding such a repeating frequency. Through the acoustical measurement in a water tunnel, the two signal processing techniques show a satisfactory result in detecting the inception of tip vortex cavitation.

关键词： tip vortex cavitation inception Short-Time Fourier Transform (STFT) Detection of Envelope Modulation On Noise(DEMON)

Chemical modification of ordered/disordered carbon nanostructures for metal hosts and electrocatalysts of lithium-air batteries

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InfoMat 2022年第1期4卷 105-129页

作者： Jeongyeon lee Tae hyung lee Ho Won Jang Ho Seok Park School of Chemical Engineering Convergence Research Center for Energy and Environmental SciencesDepartment of Health Sciences and TechnologySamsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan University(SKKU)SuwonRepublic of Korea Institute of Textiles Clothing The Hong Kong Polytechnic UniversityHung HomHong Kong SARChina Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoulRepublic of Korea

Although lithium-air batteries(LABs)are considered the promising alternative of existing lithium–ion batteries owing to their high energy density of 11680 W h kg^(-1),their practical applications are limited by the technical issues,such as unstable solid electrolyte interface and dendrite formation from metal anode and insufficient bifunctional activities and durability from cathode *** order to resolve these bottlenecks,carbon nanostructures have been investigated owing to their high surface area,excellent electrical conductivity,electrochemical stability,and various modification ***,we comprehensively review a recent progress on the design of carbon nanostructures for their applications into metal hosts,protection layers,and bifunctional electrocatalysts of *** correlation between the crystalline,electronic,porous,and chemical structures and the electrochemical properties of carbon nanomaterials are discussed depending on their classification and *** chemical modifications,such as morphological control,hierarchical architecturing,heteroatom incorporation,and the formation of composites,for the improved electrochemical performances of anode and cathode will be also ***,we deal with the perspectives for the ongoing obstruction and future guidance.

关键词： bifunctional catalysts carbon nanostructures lithium-air batteries metal anodes surface modification

All-fiber acousto-optic modulator based on a cladding-etched optical fiber for active mode-locking

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Photonics Research 2017年第5期5卷 391-395页

作者： JIHWAN KIM JOONHOI KOO ju HAN lee School of Electrical and Computer Engineering University of Seoul

An all-fiber acousto-optic modulator(AOM), which features a compact structure and a low-driving voltage, is experimentally demonstrated for the active mode-locking of a fiber laser. The proposed AOM is based on the short length of the cladding-etched fiber, the ends of which are fixed on a slide glass. On top of the cladding-etched fiber, a piezoelectric transducer was overlaid. A chemical wet-etching technique, which is based on a mixed solution of NH_4F and (NH_4)2SO_4, is used to reduce the fiber diameter down to ～25 μm, and the length of the etched section is only 0.5 cm. The fabricated device exhibited a modulation depth of 73.10% at an acoustic frequency of 918.9 kHz and a peak-to-peak electrical voltage of 10 V, while a laser beam was coupled at 1560 *** using the prepared AOM within an erbium-doped-fiber ring cavity, the mode-locked pulses with a temporalwidth of 2.66 ps were readily obtained at a repetition rate of 1.838 MHz.

关键词： All-fiber acousto-optic modulator based on a cladding-etched optical fiber for active mode-locking

Stone extraction balloon-guided repeat self-expanding metal stent placement

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World Journal of Gastroenterology 2010年第24期16卷 3087-3090页

作者： hyung Hun Kim Jeong Seop Moon Soo hyung Ryu jung Hwan lee You Sun Kim Division of Gastroenterology Department of Internal MedicineSeoul Paik Hospital Inje University College of Medicine

Self-expanding metal stent (SEMS) placement offers safe and effective palliation in patients with upper gastrointestinal obstruction due to a malignancy. Well described complications of SEMS placement include tumor growth, obstruction, and stent migration. SEMS occlusions are treated by SEMS redeployment, argon plasma coagulation application, balloon dilation, and surgical bypass. At our center, we usually place the second SEMS into the first SEMS if there is complete occlusion by the tumor. We discovered an unusual complication during SEMS redeployment. The guide-wire passed through the mesh of the first SEMS and caused the second SEMS to become entangled with the first SEMS. This led to the distortion and malfunction of the second SEMS, which worsened the gastric outlet obstruction. For lowering the risk of entanglement, we studied stone extraction balloon-guided repeat SEMS placement. This is the first report of a SEMS entangled by the mesh of the first SEMS and stone extraction balloon-guided repeat SEMS placement for lowering the risk of this complication.

关键词： Gastric outlet obstruction Self-expanding metal stent

Recognition of Association Between Blood Stasis Syndrome and Traumatic Injury among Doctors of Korean Medicine:A Cross-Sectional Observation Study

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Chinese Journal of Integrative Medicine 2018年第4期24卷 254-259页

作者： Jeeyoun jung Mi Mi Ko ju Ah lee Myeong Soo lee Korean Medicine Fundamental Research Division Korea Institute of Oriental Medicine Clinical Research Division Korea Institute of Oriental Medicine

Objective： To investigate the diagnostic indicators and herbal treatments for blood stasis syndrome（BSS） patients with traumatic injuries and to identify the association between BSS and traumatic injury in Korea. Methods： Two-hundred and four patients with traumatic injury were recruited from the Gangnam and Daejeon branches of Jaseng Hospital of Oriental Medicine between june 2014 and December 2014. Two independent doctors of Korean medicine（DKMs） determined the diagnosis of BSS or non-BSS based on the subjects＇ signs and symptoms. The scores assigned to BSS symptoms and DKMs＇ reasons for diagnosing BSS in patients with traumatic injury were investigated. Both medication and herbal prescription records from a 3-month period were collected for all patients diagnosed with BSS by both DKMs. Results： A total of 169 of 204（82.8%） patients received consistent diagnosis related to BSS by two DKMs. Among them, 54.4%（92 cases） were diagnosed with BSS, and 45.6%（77 cases） were not diagnosed with BSS. DKMs most frequently cited symptoms of recent traumatic injury as justifications for BSS diagnoses, and also selected pain-related indicators such as abdominal pain, sharp pain and nocturnal pain as important reasons in diagnosing BSS. In addition, an inconsistency in the pattern identification theory with respect to traumatic injury was observed. Although only 92 cases（54.4%） of patients were diagnosed with BSS, 77.6% of them were prescribed decoctions for BSS. Conclusions： DKMs considered traumatic injury could cause BSS, and utilized decoction for BSS in patients with traumatic injury without confirming a diagnosis of BSS because they assumed the main symptoms or pathologies of traumatic injury to be closely related to BSS.

关键词： blood stasis syndrome Korean medicine traumatic injury herbal medicine diagnosis pattern identification

Methane Conversion Using Dielectric Barrier Discharge: Comparison with Thermal Process and Catalyst Effects

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Journal of Natural Gas Chemistry 2006年第2期15卷 87-92页

作者： Antonius Indarto Jae-Wook Choi Hwaung lee hyung Keun Song Korea Institute of Science and Technology Clean Technology Research CenterP.O. Box 131CheongryangSeoul 130-650Korea

The direct conversion of methane using a dielectric barrier discharge has been experimentally studied. Experiments with different values of flow rates and discharge voltages have been performed to investigate the effects on the conversion and reaction products both qualitatively and quantitatively. Experimental results indicate that the maximum conversion of methane has been 80% at an input flow rate of 5 ml/min and a discharge voltage of 4 kV. Experimental results also show that the optimum condition has occurred at a high discharge voltage and higher input flow rate. In terms of product distribution, a higher flow rate or shorter residence time can increase the selectivity for higher hydrocarbons. No hydrocarbon product was detected using the thermal method, except hydrogen and carbon. Increasing selectivity for ethane was found when Pt and Ru catalysts presented in the plasma reaction. Hydrogenation of acetylene in the catalyst surface could have been the reason for this phenomenon as the selectivity for acetylene in the products was decreasing.

关键词： plasma dielectric barrier discharge thermal process methane conversion catalyst

Improvements of model-test method for cavitation-induced pressure fluctuation in marine propeller

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Journal of Hydrodynamics 2013年第4期25卷 599-605页

作者： lee Jeung-Hoon HAN Jae-Moon PARK hyung-Gil SEO Jong-Soo Samsung Ship Model Basin (SSMB) Marine Research Institute Samsung Heavy Industries Science Town

Although the prediction of propeller cavitation-induced pressure fluctuation strongly depends on the model-scalemeasure- ment in a cavitation tunnel, there is still a lack of correlation with full-scale data. This paper deals with the enhancement of such a correlation deficiency by improving the conventional model-test technique, two majors of which are in the following. One is to take into account the boundary layer effect of wooden fairing plate at the ceiling of water cavitation tunnel. The other is to avoid the reso- nance frequency range of model-ship via adjusting the revolution speed of model propeller. Through a case study, for which both model and full-scale test data are available, the improved method in this study shows its validness, and furthermore a close correla- tion with full scale measurement.

关键词： cavitation boundary layer resonance

Solar Power Plant Network Packet-Based Anomaly Detection System for Cybersecurity

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Computers, Materials & Continua 2023年第10期77卷 757-779页

作者： ju Hyeon lee Jiho Shin jung Taek Seo Department of Information Security Gachon UniversitySeongnam13120Korea Police Science Institute Korean National Police UniversityAsan31539Korea Department of Computer Engineering Gachon UniversitySeongnam13120Korea

As energy-related problems continue to emerge,the need for stable energy supplies and issues regarding both environmental and safety require urgent *** energy is becoming increasingly important,with solar power accounting for the most significant proportion of *** the scale and importance of solar energy have increased,cyber threats against solar power plants have also ***,we need an anomaly detection system that effectively detects cyber threats to solar power ***,as mentioned earlier,the existing solar power plant anomaly detection system monitors only operating information such as power generation,making it difficult to detect *** address this issue,in this paper,we propose a network packet-based anomaly detection system for the Programmable Logic Controller(PLC)of the inverter,an essential system of photovoltaic plants,to detect cyber *** and vulnerabilities in solar power plants were analyzed to identify cyber threats in solar power *** analysis shows that Denial of Service(DoS)and Manin-the-Middle(MitM)attacks are primarily carried out on inverters,aiming to disrupt solar plant *** develop an anomaly detection system,we performed preprocessing,such as correlation analysis and normalization for PLC network packets data and trained various machine learning-based classification models on such *** Random Forest model showed the best performance with an accuracy of 97.36%.The proposed system can detect anomalies based on network packets,identify potential cyber threats that cannot be identified by the anomaly detection system currently in use in solar power plants,and enhance the security of solar plants.

关键词： Renewable energy solar power plant cyber threat cybersecurity anomaly detection machine learning network packet