Optimal Resonance Tests for Concrete Tracks Using Microphones

Bukhari,Sung-Ho Joh,Norinah A.R 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.5

Resonance tests of concrete structures have been successfully employed for structural integrity assessment of various concrete structures. However, the nature of resonance test limited its applications due to the significant time and efforts involved in coupling contact sensors to concrete surface. Recently, some researches have been performed to introduce microphones into impact-echo tests, one of resonance tests. In this paper, additional research has been carried out to make the microphone-based resonance tests optimal for concrete tracks. The research includes optimal measurement configuration for concrete tracks, and filtering scheme of acoustic signals in time-frequency domain for extracting stress wave components only. For validity and verification of the proposed testing scheme, field applications were made at a concrete slab.

Effect of different heat treatments on oxidation-bonded SiC membrane for water filtration

Bukhari, Syed Zaighum Abbas,Ha, Jang-Hoon,Lee, Jongman,Song, In-Hyuck Elsevier 2018 Ceramics international Vol.44 No.12

<P><B>Abstract</B></P> <P>The porous SiC-based membrane has proved its validity in microfiltration membrane fabrication, but application is limited due to its high fabrication cost. In this study, the oxidation-bonding technique was used to fabricate a SiC microfiltration membrane. The oxidation behaviour exhibited during different thermal treatments was related to pore morphology, and ultimately membrane permeance. Corrosion properties of the oxidation-bonded SiC specimens were also studied. We have found that a membrane made by coating an oxidation-bonded SiC layer over a clay-bonded SiC support and sintered at 1000 °C for 3 h could make a defect-free, corrosion resistant microfiltration membrane with pure water membrane permeance above 700 LMH per bar over the 1 h operation time. The membrane has a narrow pore size distribution, with an average pore size of 78 nm.</P>

The Analgesic, Anti-inflammatory and Calcium Antagonist Potential of Tanacetum artemisioides

Bukhari, Ishfaq Ali,Gilani, Anwar-Ul Hassan,Shah, Abdul Jabbar,Hussain, Javid,Khan, Rafeeq Alam 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.3

Several species of the genus Tanacetum are traditionally used in a variety of health conditions including pain, inflammation, respiratory and gastrointestinal disorders. In the current investigation, we evaluated the plant extract of T atemisioides and some of its pure compounds (flavonoids) for analgesic, anti-inflammatory and calcium antagonist effects in various in-vivo and in vitro studies. Using the actetic acid induced writhing test, intraperitoneal (i.p) administration of the plant extract (25-50 mg/kg) and its flavonoid compounds TA-1 and TA-2 (1-5 mg/kg) exhibited significant analgesic activity. The maximum analgesic effect observed with the crude extract of the plant was 71% at 50 mg/kg, while that of compounds TA-1 and TA-2 (5mg/kg i.p)was 75 and 47%, respectively. The plant extract and its pure compounds caused inhibition of formalin induced paw licking in mice predominatly in the second phase of the test. Diclofenac sodium, a standard reference compound, showed a similar effect in these chemical induced pain models. In the carrgeenan induced rat paw edema assay, the plant extract (50-200 mg/kg i.p) demonstrated significant (P<0.01) anti-inflmmatory activity which was comparable to that obtained with diclofenac sodium and indomethacin. In isolated rabbit jejunum preprations the piant extract showed an atropine sensitive dose-dependant (0.10-1.0 mg/mL) spasmogenic activity followed by a spasmolytic effect at the next higher doses (3-5 mg/mL). The crude extract of the plant also inhibited the high K$^+$-induced contractions, indicating a calcium channel blocking (CCB) activity, which was further confirmed when the plant extract caused a right-ward shift in the Ca$^{++}$ concentration response curves in the isolated rabbit jejunum preparations, similar to that seen with verapamil. The flavonoid compounds isolated from the plant were devoid of any activity in the isolated tissue preparations. These results indicate that the plant extract of T. artemisioides possesses analgesic, anti-inflammatory and CCB activities. The flavonoid compounds of the plant may have a role in its observed analgesic and anti-inflammatory activities, while the CCB activity of the plant may be attributed to some other chemical constituents present. Moreover the findings support the traditional reputation of the genus Tanacetum for its therapeutic benefits in pain and inflammatory conditions.

A Three-Phase Line-Interactive UPS System to Eliminate the Inrush Current Phenomenon during Switching-in of an Auxiliary Load while Powering the Main Load

Bukhari, Syed Sabir Hussain,Ayub, Muhammad,Kwon, Byung-il The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.4

Normally, various auxiliary loads are installed along with the main load in industrial applications. Usually, load transformers are used to convey such types of auxiliary loads. The transformers become energized when the loads are turned-on, consequently, high amplitude of inrush current appears at the output of the uninterrupted power supply (UPS) system. To mitigate these high current amplitudes, this manuscript suggests a three-phase line-interactive UPS system to counter the inrush current during the turning-on of the auxiliary load transformer while powering the main load by using a current controlled inverter. Experimental results of a laboratory-sized prototype are provided in the support of the proposed UPS system for validation.

An interval type-2 fuzzy logic based strategy for microgrid protection

Bukhari, Syed Basit Ali,Haider, Raza,Saeed Uz Zaman, Muhammad,Oh, Yun-Sik,Cho, Gyu-Jung,Kim, Chul-Hwan IPC Science and Technology Press 2018 International journal of electrical power energy s Vol.98 No.-

<P><B>Abstract</B></P> <P>The concept of microgrids has been introduced to facilitate the integration of the distributed energy resources (DERs) into distribution networks in a more economical, reliable and environment-friendly manner. One of the critical challenges associated with microgrids is devising an appropriate protection strategy. This is because the fault current level continuously varies owing to the existence of DERs and to the fact that the microgrid can operate in grid-tied and islanded modes. This paper proposes a new protection strategy for microgrids using an interval type-2 fuzzy logic system. The proposed strategy considers various uncertainties associated with faults and employs two different fuzzy systems to detect, classify, and locate the faults in microgrids. The phase angle between superimposed modal voltage and modal current is used as an input to the fuzzy system designed to identify the fault direction. The significant feature of the proposed strategy is that it can protect the microgrid after a single-phase tripping event. To validate the effectiveness of the proposed strategy, we have performed extensive simulations using MATLAB/SIMULINK. The simulation results show that the proposed strategy can detect, classify, and isolate various faults in the microgrid. Moreover, the strategy also provides backup protection in case of failure of the primary protection.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Develop a new microgrid protection strategy based on interval type-2 fuzzy logic system. </LI> <LI> Considers various uncertainties associated with faults in microgrids. </LI> <LI> Identify fault direction using phase angle between superimposed modal voltage and modal current. </LI> <LI> Capable to protect the microgrid after a single-phase tripping event. </LI> </UL> </P>

A Cost-Effective, Single-Phase Line-Interactive UPS System that Eliminates Inrush Current Phenomenon for Transformer-Coupled Loads

Bukhari, Syed Sabir Hussain,Atiq, Shahid,Lipo, Thomas A.,Kwon, Byung-il The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Sudden voltage drops and outages frequently disturb the operation of sensitive loads for domestic, commercial, and industrial use. In some cases, these events may even impair the functioning of relevant equipment. To maintain power under such conditions, a UPS system is usually installed. Once a disturbance happens at the grid side, the line-interactive UPS system takes over the load to prevent an interruption. But, due to magnetic saturation of the transformer, a significant inrush current may occur for the transformer-coupled loads during this transition. The generation of such transient currents may in turn decrease the line voltage and activates over-current protecting devices of the system. In this work, a cost-effective, line-interactive UPS system is proposed that eliminates the inrush current phenomenon associated with transformer-coupled loads. The strategy was implemented by connecting a standard current-regulated voltage source inverter (CRVSI) to the secondary winding of the load transformer. During any transient condition at the grid side, the load current is monitored and regulated to achieve either seamless compensation of the load current or complete transferal of load from grid to the inverter. Experimental results were obtained for a prototype under all possible operating conditions so as to validate the performance of the proposed topology.

Providing multicast services over SDN-evolved LTE network: Architecture, procedures and performance analysis

Bukhari, JanFizza,Park, Jun-Hyuk,Yoon, Wonyong Elsevier 2018 Journal of Computer Communications Vol.127 No.-

<P><B>Abstract</B></P> <P>The recent innovation in cellular technologies like LTE/LTE-Advanced has increased the demand of high bandwidth services e.g. mobile Internet Protocol TV (IPTV), on-demand video streaming etc. However, current cellular multicast service called Evolved Multimedia Broadcast Multicast Service (eMBMS) is not enough in terms of IPTV service provisioning, flexibility, and efficiency. Software-defined networking (SDN) being an emerging networking paradigm offers its services to program such cellular networks, providing a remotely configurable forwarding plane. This paper enlightens the notion of SDN in cellular multicast data transmission within eMBMS networks. It presents an objective sketch of transforming current multicast cellular communication into OpenFlow based SDN-evolved communication. We perform the first fine-grained analysis of common multicast procedures (group join, handover etc.) involved in both the current and SDN-evolved eMBMS network along with the supporting simulation results while providing multimedia services to the users. Considering user plurality of multicast services, we model the user requests as independent events of a Zipf-like distribution and find out the correlation among multimedia content popularity, operational load on the network and delay metrics. This paper provides a comparison of both the networks, summarizes the significant differences between the two, and highlights the effectiveness of our proposed SDN-evolved multicast approach in terms of minimized network operations, reduced delays, reliable and streamlined multicast tree construction.</P>

Viscosity Study to Optimize a Slurry of Alumina Mixed with Hollow Microspheres

Bukhari, Syed Zaighum Abbas,Ha, Jang-Hoon,Lee, Jongman,Song, In-Hyuck The Korean Ceramic Society 2015 한국세라믹학회지 Vol.52 No.6

Porous alumina ceramics are involved in many industrial applications due to the exceptional properties of these products. This study addresses the preparation of porous alumina ceramics using hollow microspheres as a pore-forming agent and slip casting as a green-body-forming technique. A uniform distribution of pores is a basic requirement of a porous material. This study investigates three different slurry systems, i.e., as-prepared alumina slurry, alumina slurry electrostatically dispersed by hydrochloric acid (HCl), and slurry dispersed by the commercial dispersant 'Darvan C-N'. At a low viscosity, the hollow microspheres in the slurry tend to float, which causes a non-uniform pore distribution. To avoid this phenomenon, the viscosity of the slurry was increased to the extent that the movement of hollow microspheres ceased in the slurry. As a result, a uniform pore distribution was achieved.

Incorporation of Fuzzy Theory with Heavyweight Ontology and Its Application on Vague Information Retrieval for Decision Making

Bukhari, Ahmad C.,Kim, Yong-Gi Korean Institute of Intelligent Systems 2011 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.11 No.3

The decision making process is based on accurate and timely available information. To obtain precise information from the internet is becoming more difficult due to the continuous increase in vagueness and uncertainty from online information resources. This also poses a problem for blind people who desire the full use from online resources available to other users for decision making in their daily life. Ontology is considered as one of the emerging technology of knowledge representation and information sharing today. Fuzzy logic is a very popular technique of artificial intelligence which deals with imprecision and uncertainty. The classical ontology can deal ideally with crisp data but cannot give sufficient support to handle the imprecise data or information. In this paper, we incorporate fuzzy logic with heavyweight ontology to solve the imprecise information extraction problem from heterogeneous misty sources. Fuzzy ontology consists of fuzzy rules, fuzzy classes and their properties with axioms. We use Fuzzy OWL plug-in of Protege to model the fuzzy ontology. A prototype is developed which is based on OWL-2 (Web Ontology Language-2), PAL (Protege Axiom Language), and fuzzy logic in order to examine the effectiveness of the proposed system.

Using OpenDaylight SDN Controller with ns-3 Network Simulator

Janfizza Bukhari(부카리 잔피자),Junhyuk Park(박준혁),Wonyong Yoon(윤원용) 한국정보기술학회 2019 Proceedings of KIIT Conference Vol.2019 No.6