https://repository.rmutp.ac.th:443/handle/123456789/85 2013-06-01T21:15:19Z https://repository.rmutp.ac.th:443/handle/123456789/917 Novel Water Level Sensing for the Canals in Bangkok พันธุนะ, ณัฐพงศ์; เดชเดชะ, ศุภชัย; ราวิชัย, เฉลิมฤทธิ์ Department of drainage and sewerage (DDS) has realised in the flooding in Bangkok. Despite these issues, the flood control centre has been established for water level monitoring as well as solving its issue in case of the water level in canal over-leveled using supervisory control and data acquisition (SCADA) technology in order to control the pumping station located throughout Bangkok. This regulation system is mainly categorised into two systems: Field Server and Canal Regulation. Consequently, this article presents on Novel Water Level Sensing for the Canals in Bangkok with the advantage and disadvantage analysis in the informative-acquiring pattern from instruments together with the limitations of operation for improving measurement more precise, reliable and most efficient. วารสารวิชาการและวิจัย มทร.พระนคร, 6 (1) : 169-179 2012-03-29T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/782 An Alerting Wireless Sensor System for Long Period of Immobilized Elderly in a Residential Room Nilas, Nilamit This paper presents a low cost wireless sensor network system which is developed to be an alerting system for relatives or caregivers when the elder is immobile for a long period. The alerting signal is sent via the Internet link and a mobile phone. Remote transducers capture input signal from the mobility subject. If the target subject has immobilized behavior for long period, which is analyzed abnormal condition, the system will send the alerting messages to a selected mobile phone or Internet link. After detection of motionless elder from the set–point periods, the system immediately distributes messages via SMS on the mobile network and a server to warn a relative or a caregiver with the image option to send. The sensor modules have ease-ofinstallation with coverage area nearly 3 square meters, 80 % of detection level suitable for a small room and a bathroom รายงานการวิจัย--มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร, 2554 2011-05-18T02:12:02Z https://repository.rmutp.ac.th:443/handle/123456789/340 Analysis and control of Shunt-Compensator for mitigating Unbalanced Voltages Srisongkram, W.; Phanthuna, N.; Boonchiam, P.; Subsingha, W.; Mithulananthan, N. This paper presents the analysis and the control of shunt-compensator for improving unbalanced voltages of power distribution systems in Thailand. The shunt-compensator is connected to the low voltage level in power distribution system. The analysis detail and the design of shunt-compensator obtain by using the voltage vector control (mathematical model with the stationary reference frame and synchronous reference frames). The unbalanced voltages are identified by using positive and negative sequence detection that can be shown in the synchronous reference frame. This method also presents the decoupling control including feed-forward control to compensate both positive and negative sequence component of grid voltage. The power circuit of the shunt-compensator and the distribution network are modeled by Provincial Electricity Authority (PEA) of Thailand that is the same as worldwide standard of power distribution system. By using computer program, the simulation results showed the benefit and the performance of proposed methodology which obviously ensure the performance of shunt-compensator for mitigating the unbalanced voltages. This paper presents the analysis and the control of shunt-compensator for improving unbalanced voltages of power distribution systems in Thailand. 2008-08-05T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/339 การวิเคราะห์ระบบแถวคอย, กรณีศึกษาการรับสมัครนักศึกษามหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร วิทยาเขตพระนครเหนือ พลสุวัตถิ์, ดำรงฤทธิ์ The objectives of the study were to find the arrival rate of applicants who applied to study at Rajamangala university of Technology Pra Nakhon, North Bangkok Campus, the service rate of admission officers, and to analyze queuing system in order to improve the admission system. The sample was 1,722 technical students who applied to study in 10 divisions in 2007 and 2008. The application data was collected every 10 minutes in each one-hour period from 09.00 am. to 16.00 pm. for 6 days. The study found that the distribution of the number of applicants was Poisson distribution. The highest arrival rate, 1.29 students/min, was at the second period and the lowest arrival rate, 0.06 students/min, was at the sixth period. The distribution of service time at each station was exponential distribution. The highest service rate, 0.67 min/student or 1.49 students/min, was at the second station, entering data into a computer. Queuing analysis in this study was series network. The analysis found that the highest expected number of applicants in the system, 150 students/hour, was at the first station in the second period, and in the sixth period there was almost none. The highest expected number of applicants in the queuing system, 107.40 students/hour, was at the first station in the second period. The highest expected waiting time in the system, 1.92 min/student and in the queuing system, 1.37 min/student were at the first station. The probabilities of none of applicants in the system at the first, the second and the third station in the sixth period were high, 0.97,0.95, and 0.98 respectively. The proper value of the expected number of applicants in the system set in this study was not more than 60 students/hour and not less than 30 students/hour. The proper value of the waiting time in the system was not more than 1 min/student and not less than 0.5 min/students for stations with more than one servers. The analysis found that at the first station one more server should be added in the second, the third and the forth period, and one less server should be reduced in the sixth period. The objectives of the study were to find the arrival rate of applicants who applied to study at Rajamangala university of Technology Pra Nakhon, North Bangkok Campus, the service rate of admission officers, and to analyze queuing system in order to improve the admission system. The sample was 1,722 technical students who applied to study in 10 divisions in 2007 and 2008. The application data was collected every 10 minutes in each one-hour period from 09.00 am. to 16.00 pm. for 6 days. 2008-01-01T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/338 การวิเคราะห์ความอยู่รอด : การศึกษาการออกกลางคันของนักศึกษา ปวส. สายช่างอุตสาหกรรม มหาวิทยาลัยเทคโนโลยีราชมงคลพระนคร วิทยาเขตพระนครเหนือ แสงมา, วัชรินทร์; ทองขาว, พิษณุ; ศิริมา, พรพิศ The objectives of the study were to find the survival probabilities, the hazard rates of dropping out of the technical diploma level students at Rajamangala University of Technology Phra Nakhon, North Bangkok Campus, and the factors influencing on the hazard rates of students dropout. The sample was the students enrolling in the university in 2005. The study found that for the first semester, the survival probabilities of students in all divisions were high, ranging from 0.9210 to 1.00. For the second semester, the survival probabilities of students in all divisions ranged from 0.7820 to 0.8815 except Industrial Technology which had a maximum value of 0.9295 and Metal Technology which had a minimum value of 0.6271. For the third and the fourth semester, there were 6 divisions which had survival probabilities ranging from 0.7142 to 0.7971. They were Tool and Die Making, Computer Technology, Electrical Technology, Electronics, Automatic Machine, and Production design. There were 4 divisions which had survival probabilities ranging from 0.8275 to 0.8732. They were Mechanical Tool Technology, Business Computer, Mechanical Power, and Industrial Technology. The division of Metal Technology had the minimum value of 0.5932. For the first semester, the hazard rates of dropping of students in all divisions were low, ranging from 0.00 to 0.0822. For the second semester, the hazard rates of dropping of students in all divisions ranged from 0.1260 to 0.2458 except Industrial Technology which had a minimum value of 0.0730 and Metal Technology which had a maximum value of 0.5221. For the third and the fourth semester, the hazard rates of dropping of students in all divisions ranged from 0.1355 to 0.2962 except Metal Technology which had the maximum value of 0.5932 and Tool and Die Making which had the value of 0.3364. The factors influencing on hazard rates of students dropout were place of previous school, region of previous school, and grade point average of previous school. The hazard rate of dropping of students graduating from schools in the central region (not including Bangkok Metropolitan Area) was 43.8% (0.562 times) less than the hazard rate of dropping of students graduating from schools in Bangkok Metropolitan Area. The hazard rate of dropping of students having grade point average of 3.10-3.50 and 3.51-4.00 from previous school was 43.1% (0.569 times) and 63.7% (0.377 times) less than the hazard rate of dropping of students having grade point average of 2.00-2.50 respectively. The objectives of the study were to find the survival probabilities, the hazard rates of dropping out of the technical diploma level students at Rajamangala University of Technology Phra Nakhon, North Bangkok Campus, and the factors influencing on the hazard rates of students dropout. The sample was the students enrolling in the university in 2005. 2008-01-01T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/337 Using Condensate Water to Reduce Heat for Finned-Tube Condenser of Air Conditioning System Puangcharoenchai, Somjin Now a day the mostly air condition are use vapor compression refrigeration system in which R-22 refrigerant is used as a working substance. From the results of study, it found that the quantity of water vapor or moisture in the air is condensed with in the fan coil unit while through out the evaporator. The fluid after condense is called condensed water. By this process, the quantity of condensed water is increases when the air condition is used in the long time. To increase the utility, the condensed water is recovered for the heart reduction in the finned-tube condenser. The experiment is consist of two conditions by using the air and condensed water to heart reduction. But in case of condensed water, the pressure operation is controlled at 280 and 260 Psig respectively. The results of experiment shown the refrigeration effect, coefficient of performance (C.O.P) and energy efficiency ratio (EER) is 39,675 Btu/hr, 3.01 and 10.3 Btu/hr.Watt respectively with the air is used. At the pressure operation 280 Psig, refrigeration effect, (C.O.P) and (EER) is 44,212 Btu/hr, 3.38 and 11.5 Btu/hr.Watt respectively and 49,856 Btu/hr, 3.99 and 13.6 Btu/hr.Watt at pressure operation 260 Psig. Furthermore, the capacity of condenser is increases to 11.43% and 25.6% and also the refrigerant efficient is increases to 12.43% and 32.43% at the pressure operation 280 and 260 Psig. Thus, the parameter of the energy efficiency ratio depends on the capacity of condenser, working substance temperature (pressure operation) and air surrounding temperature. The mostly air condition are use vapor compression refrigeration system in which R-22 refrigerant is used as a working substance. 2007-01-01T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/336 The factors of resource and educational investment affecting to the number of the post graduate students of Rajamangala University of Technology Phra Nakorn Wirotcheewan, Prasert The objective of this research is to study the factors of resource and investment affecting to the number of post graduate students of Rajamangala University of Technology Phra Nakorn. The samples of this research are to survey the group of lecturers from 9 faculties by answering the questionnaires. The objective of this research is to study the factors of resource and investment affecting to the number of post graduate students of Rajamangala University of Technology Phra Nakorn. 2008-01-01T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/335 The Analysis of high-Voltage Electric Field Stress in Lp and Ls coils of Tesla Transformer for studying the efficiency design Thongkeaw, Somkieat; Nedphograw, Supawud; Plangklang, Boonyang; Apiratikul, Promsak This article presents The Analysis for high-Voltage Electric Stress in Lp and Ls coils of Tesla Transformer for studying the efficiency design. The tesla transformer is designed at 350kV rating Voltage and 120 kHz resonant frequency. The effect of high voltage when we designed the coil has impact to Electric Stress between primary and secondary coil because the tesla transformer uses air core. The insulator of coil also has problem on the reason as flashover on the 2 coils. The best dimension among coil has to present in this paper by using optimal mathematical solution. The simulation results show performance of the solution and ensure the methodology with positive way. This article presents The Analysis for high-Voltage Electric Stress in Lp and Ls coils of Tesla Transformer for studying the efficiency design. The tesla transformer is designed at 350kV rating Voltage and 120 kHz resonant frequency. 2008-01-01T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/334 Study of Ozone Generator with Electric Fields Distribution on Water Surface Charlangsut, Aroon; Boonthienthong, Manat; Thongkeaw, Somkieat; Boonchiam, Paisan This paper proposes a study of an Ozone generator. The generator under the study is designed using the electrode with uniform field. The electrode is constructed in the plane shape with positive potential. The transformer oil is used as insulating materials to prevent discharges around the electrode discharges in the air void depends on the size, the types of dielectrics and level of applied voltage. Between the electrode and the air void, there is acyclic dielectric. The stainless electrode with water is used as a ground potential. The breakdown depends on the electric field intensity. It is found that there is sufficient amount of ozone due to the ionization, Development and design ozone generator this research electric field intensity on the water type and this can be used as a principle to construct a new type of ozone generator. This paper proposes a study of an Ozone generator. The generator under the study is designed using the electrode with uniform field. 2008-08-27T00:00:00Z https://repository.rmutp.ac.th:443/handle/123456789/333 Power Efficient Ant Colony System Wireless Sensor Networks Using Adaptive Node Function วัยวุฒิ, วณพันธ์; รุจิพัฒนพงศ์, ศิริชัย Today wireless sensor networks are developed and comprised of a small fully autonomous processing, communication and sensing devices. It has been restricted power supply, low computing power. WSNs work in vast area, unreachable or crucial area, send and receive raw data from each sensor node. It has the ability to cooperatively collect data and retransmit in order to process or alert. This paper, used ns-2 simulation, propose a power efficient wireless sensor network ant colony system that can adapt it’s function to reduce average energy consumption per node and work in area for a longer time. This paper, used ns-2 simulation, propose a power efficient wireless sensor network ant colony system that can adapt it’s function to reduce average energy consumption per node and work in area for a longer time. 2008-11-23T00:00:00Z