MEMS-based particle detection system for measuring airborne ultrafine particles

Kim, Hong-Lae,Han, Jangseop,Lee, Sang-Myun,Kwon, Hong-Beom,Hwang, Jungho,Kim, Yong-Jun Elsevier 2018 Sensors and actuators. A Physical Vol.283 No.-

<P><B>Abstract</B></P> <P>A MEMS-based particle detection system which includes a particle processing chip and electronic circuits was developed for low-cost and ubiquitous monitoring of airborne ultrafine particles. The detection system consists of particle classification, charging, precipitation, and sensing sections. Particles with different sizes enter the ultrafine particle processing chip and are separated according to their sizes in the classification section. Size-classified particles are charged in the charging section. Then, the mean size and particle concentrations are determined in the precipitation and sensing sections. The particle classification, charging, and precipitation sections were integrated on a single chip using MEMS and microfluidic technologies. The particle sensing section was realized using a metal filter connected to a high-precision electrometer. The characteristics of each section were first analyzed, and the proposed particle detection system was then compared with standard commercially available instruments. The calculated particle number concentrations correspond to the results measured by commercially available instruments. The proposed particle detection system can be applied for monitoring of ultrafine particles with size range of 20–300 nm (20–130 nm particle mean diameter) and concentration range of 320–10<SUP>6</SUP> particles/cm<SUP>3</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We proposed MEMS-based detection system for monitoring airborne ultrafine particles. </LI> <LI> Airborne ultrafine particles were classified according to their particle diameter. </LI> <LI> The proposed system can measure the number concentration of ultrafine particles. </LI> <LI> The proposed system was successfully applied in indoor environments. </LI> </UL> </P>

Development of a Holographic Particle Diagnostic System and Its Application to Measurements of Spray Characteristics

Y. J. Choo,B. S. Kang 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.1

Particle diagnostics involving three dimensional distributions are important topics in many engineering fields. The holographic system is a promising optical tool for measuring three dimensional features of particles. In this study, we developed a holographic particle diagnostic system with diffused illumination to measure the sizes and 3-D velocities of moving particles using automatic image processing. First, basic optical systems for pulse laser recording, continuous laser reconstruction, and image acquisition were constructed. One of inherent limitations of particle holography is its long depth of focus in particle images, which causes considerable difficulty in determination of particle positions in the optical axis. To solve this problem, three new auto-focusing parameters (AFPs) corresponding to particle sizes were introduced. The developed system was applied to spray droplets to validate its capabilities. Three dimensional positions of particles viewed from two sides were decided using AFPs and then three dimensional particle velocities were extracted using a particle tracking algorithm. Comparison of measured sizes and three dimensional velocities of particles with those obtained using a laser instrument, PDPA (Phase Doppler Particle Analyzer), showed that the developed holographic system produced consistent results.

PSO-PID를 이용한 시소 시스템의 위치제어기 구현

손용두(Yong Doo Son),방상우(Sang Woo Bang),손준익(Jun Ik Son),임영도(Young Do Lim) 한국정보기술학회 2009 Proceedings of KIIT Conference Vol.2009 No.-

본 논문에서는 PSO-PID를 이용하여 시소 시스템의 균형을 위한 PID 위치 제어기를 설계하고자 한다. 시소시스템은(Seesaw System) 선박 및 항공 역학, 도립진자, 각종 분석, 로봇 시스템 등의 해석에 광범위하게 응용되는 시스템이자 현대 제어 시스템의 이론과 각종 응용문제를 취급할 수 있는 장치이다. 또한 비선형성이 강한 제어 대상이므로 시스템의 이해와 해석, 그리고 파라미터의 정확한 선정이 필수요소이다. 본 논문에서 사용할 시스템 제어 알고리즘으로는 간단하고 안정성이 보장된 PID 제어와 정확하고 빠른 PID 파라미터 동조에 필요한 연산 최적화 알고리즘인 PSO(Particle Swarm Optimization) 통해 외란이나 제어기의 변화에 빠르게 적응할 수 있도록 하여 성능과 안정성을 보장한다. In this paper, Position Controller for balance of Seesaw System design using PID Algorithm. Seesaw System is that it's system use widely to analyze of ship or flight dynamics, Inverted Pendulum and, Robot System, manage system for theory of modern control system and all sorts of analysis. In case of Seesaw System, it's necessity that understand and analysis of system and correct selection of parameter because the system is strong nonlinear control system. It guarantees efficiency and stability to adapt quickly for disturbance or change of controller from PID Algorithm of guarantee safe from simple and long history and PSO(Particle Swarm Optimization) that sort of metaheuristic optimization that need to accuracy and fast PID parameter tuning.

파우더 수송시스템의 공기입자 유동 압력강하 특성

김종순(Jong-Soon Kim),정성원(Sung-Won Chung),권순구(Soon-Gu Kwon),박종민(Jong-Min Park),최원식(Won-Sik Choi),권순홍(Soon-Hong Kwon) 한국산업융합학회 2017 한국산업융합학회 논문집 Vol.20 No.2

The pressure drop characteristics of air particle flow in a powder transport piping system were analyzed in this study. The pressure drop characteristics of air particle flow in the piping system have not well understood due to the complexibility of particle motion mechanism. Particles or powders suspended in the air flow cause the increase of the pressure drop and affect directly transport efficiency. In this study, the pressure drop in a powder transport piping system was analyzed with interactions of air flow and particle motion in straight and curved pipes. The total pressure drop increased with pipe length, mixture ratio, and friction factor of particles because of increased friction loss of air and particles in the piping system. For the coal powders of 74 ㎛size and powder-to-air mass mixture ratio of 0.667, the total pressure drop under the consideration of powders and air flow was calculated as much as 30% higher than that air flow only.

Analysis of Force Acting on the Non-Spherical Particle Near a Wall

이세영,현지연 대한의용생체공학회 2015 Biomedical Engineering Letters (BMEL) Vol.5 No.4

Purpose To investigate the non-spherical particle dynamicsnear a wall in a vasculature, it is required that detailed forcewith respect to the particle angle and separation distance. Theprismatic particles with different cross sections are employedto study the forces on the particle in linear shear flow. Methods The force on the particle at the proximity of thewall in linear shear flow is evaluated. Fluid dynamicssimulation is performed by using Fluent software. Toinvestigate the effect of particle non-sphericity, triangular,rectangular and hexagonal prisms are considered. Results As the particle places close to the wall, the interactionbetween particle and wall increase. Due to the particle nonsphericity,the periodic force fluctuation is observed and thisfeature is important as the particle approaches to the wall. The number of apex of the cross sectional geometry issignificant on the force on the particle by fluid. Conclusions The interaction between particle and the wallinduces force imbalance so that it is predicted that the particlegeometry will influence on the particle dynamics in thevascular flow. The particle cross sectional shape and particlenon-sphericity are important factors in designing particlebaseddrug delivery system.

Power extraction efficiency optimization of horizontal-axis wind turbines through optimizing control parameters of yaw control systems using an intelligent method

Song, Dongran,Fan, Xinyu,Yang, Jian,Liu, Anfeng,Chen, Sifan,Joo, Young Hoon Elsevier 2018 APPLIED ENERGY Vol.224 No.-

<P><B>Abstract</B></P> <P>To optimize the power extraction from the wind, horizontal-axis wind turbines are normally manipulated by the yaw control system to track the wind direction. How is the potential power extraction efficiency of such wind turbines related to the parameter optimization of a yaw control system? We intend to answer this question in this study. First, we develop two control systems, a direct measurement-based conventional logic control (Control system 1), and a soft measurement-based advanced model predictive control (Control system 2). Then, a multi-objective Particle Swarm Optimization-based method is introduced to optimize control parameters and search for the Pareto Front, which represents different potential performance. On this basis, result investigation and analysis are carried out on an electrical yaw system of China Ming Yang 1.5 MW wind turbines based on three wind directions with different variations. Experimental results show that, under a large wind direction variation and with a 14% yaw actuator usage, 0.32% and 0.8% more power extraction efficiency are gained by Control system 1 and 2, respectively, after optimization. The achievable power extraction efficiency for the two yaw control systems goes down when the allowable yaw actuator usage is reduced. For instance, when the yaw actuator usage is 14%, 4.9% and 2%, the efficiency is 97.19%, 96.76% and 96.37% for Control system 1, and is 97.73%, 96.76% and 95.45% for Control system 2, respectively. Therefore, Control system 2 takes precedence over Control system 1 for having higher efficiency when the allowable yaw actuator usage is more than 4.9%. We also find that the potential power extraction efficiency of the two control systems is significantly influenced by the wind direction variation, that is, the optimized efficiency under small wind direction variation is 1.5% higher than that under large wind direction variation. In addition, the parameters of Control system 1 need to be re-optimized according to the wind condition, whereas the ones of Control system 2 may not. Finally, a novel yaw control strategy employing the optimized parameters as the query tables is suggested for the real applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two favorable yaw control systems are developed and optimized. </LI> <LI> Intelligent optimization method is proposed to optimize the potential performance. </LI> <LI> Power extraction efficiency is optimized by 0.32% and 0.8% for two control systems. </LI> <LI> Optimized efficiency under small wind variation is 1.5% more than the large variation one. </LI> <LI> Novel yaw control strategy employing optimized parameters is suggested. </LI> </UL> </P>

일반논문1 : 미군정기 검인정 중등 문법 교과서의 조사 관련 문법 지식의 체계 구조화 연구

오현아 ( Hyeon Ah Oh ) 한국어교육학회(구 한국국어교육연구학회) 2013 국어교육 Vol.0 No.143

This article tries to conduct research with its period of interest limited to the times from the US military government to the foundation of the Korean government in the horizontal dimension of the history of Korean language education under its awareness of the fact that work on Korean language textbooks since the National Liberation has been an important basis for the establishment of the identity and framework of the Korean language subject under the Curriculum led by the government. Moreover, in the sense that it initiates full-scale discussion of the structuring of the current grammar knowledge system in school grammar and contrastive analysis on the side of the structuring of the knowledge of grammar with the approved and certified grammar textbooks in the period of the American military government before the unified grammar and the foundation of the Korean government as its subjects, this article takes particles, alias Josa`s in Korean, as its subjects. Also, it tries to review changes in the methods of the description of particle-related grammatical categories through the comparison of the systems and descriptive methods in the grammar textbooks at that time with those in the grammar textbooks in the 7th Curriculum period. In the practical course of analysis, of the issues of 1) the distinction between particles and endings, 2) the classification of particles, and 3) the extent of the description of particle-related grammatical knowledge, the first in turn is addressed by ramifying it into problems ‘of the category of the particles and of Case,’ ‘of the establishment of Jijeongsa ‘copula’ or Jonjaesa ‘verb of existence,’ ‘of the establishment of conjunctions,’ and ‘of the distinction between adverbial particles and conjunctive particles,’ and the third into problems ‘of the presentation of phonologically conditioned allomorphs,’ ‘of the presentation of morphologically conditioned allomorphs due to changes in honorifics and tenses,’ ‘of the description of the aspects of the combination among particles,’ ‘of the description of grammaticalization-related contents,’ and ‘of the establishment of null morphs.’ The analysis of the structure of the grammatical knowledge system related with particles in the grammar textbooks for the secondary education in the US military government period in which interest in the Korean language and grammar was extremely exalted after the National Liberation and diverse methods of the description of grammar were tried with the approval and certification system under the particular situation of the US military ruling is expected to contribute itself to the exploration of an effective structure of particle-related grammatical knowledge. Specifically, we can hope with this study to confirm the historical changes in the classification of particles, their semantic functions, explanatory methods for particles etc. Also, such exploration of the structure of the grammatical knowledge system related with particles is expected to have something to suggest to education of Korean grammar for foreigners as well as the development of grammar textbooks later and grammar for natives.

문법교육사의 횡적 차원에서 미군정기 검인정 중등 문법 교과서의 품사 설정과 분류 문제 연구(2)

오현아 ( Oh Hyeon-ah ) 한국어교육학회(구 한국국어교육연구학회) 2017 국어교육 Vol.0 No.157

This article tries to conduct research with its period of interest limited to the times from the US military government to the foundation of the Korean government in the horizontal dimension of the history of Korean language education under its awareness of the fact that work on Korean language textbooks since the National Liberation has been an important basis for the establishment of the identity and framework of the Korean language subject under the Curriculum led by the government. Moreover, in the sense that it initiates full-scale discussion of the structuring of the current grammar knowledge system in school grammar and contrastive analysis on the side of the structuring of the knowledge of grammar with the approved and certified grammar textbooks in the period of the American military government before the unified grammar and the foundation of the Korean government as its subjects, this article takes particles, alias Josa`s in Korean, as its subjects. Also, it tries to review changes in the methods of the description of particle-related grammatical categories through the comparison of the systems and descriptive methods in the grammar textbooks at that time with those in the grammar textbooks in the 7th Curriculum period. The process of actual analysis was divided into: 1) the level of part-of -speech classification; and 2) the level of individual part-of-speech description. Part-of-speech classification was again divided into postposition establishment, i-predicative particle establishment, existential predicate establishment, conjunction establishment, and predicative particle establishment, and individual part-of-speech description into verb, adjective, postposition, i-predicative particle, existential predicate, conjunction, and predicative particle problems. The analysis of the structure of the grammatical knowledge system related with particles in the grammar textbooks for the secondary education in the US military government period in which interest in the Korean language and grammar was extremely exalted after the National Liberation and diverse methods of the description of grammar were tried with the approval and certification system under the particular situation of the US military ruling is expected to contribute itself to the exploration of an effective structure of particle-related grammatical knowledge. Specifically, we can hope with this study to confirm the historical changes in the classification of particles, their semantic functions, explanatory methods for particles etc. Also, such exploration of the structure of the grammatical knowledge system related with particles is expected to have something to suggest to education of Korean grammar for foreigners as well as the development of grammar textbooks later and grammar for natives.

PSO를 이용한 인공면역계 기반 자율분산로봇시스템의 군 제어

김준엽(Jun Yeup Kim),고광은(Kwang-Eun Ko),박승민(Seung-Min Park),심귀보(Kwee-Bo Sim) 제어로봇시스템학회 2012 제어·로봇·시스템학회 논문지 Vol.18 No.5

This paper proposes a distributed autonomous control method of swarm robot behavior strategy based on artificial immune system and an optimization strategy for artificial immune system. The behavior strategies of swarm robot in the system are depend on the task distribution in environment and we have to consider the dynamics of the system environment. In this paper, the behavior strategies divided into dispersion and aggregation. For applying to artificial immune system, an individual of swarm is regarded as a B-cell, each task distribution in environment as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows: When the environmental condition changes, the agent selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other agent using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. In order to decide more accurately select the behavior strategy, the optimized parameter learning procedure that is represented by stimulus function of antigen to antibody in artificial immune system is required. In this paper, particle swarm optimization algorithm is applied to this learning procedure. The proposed method shows more adaptive and robustness results than the existing system at the viewpoint that the swarm robots learning and adaptation degree associated with the changing of tasks.

PV 시스템의 최적 배치 문제를 위한 이산 PSO에서의 규칙 기반 하이브리드 이산화

송화창(Hwachang Song),고재환(Jae-Hwan Ko),최병욱(Byoung-Wook Choi) 한국지능시스템학회 2011 한국지능시스템학회논문지 Vol.21 No.6

본 논문은 배전망에서의 PV (photovoltaic) 발전 시스템의 최적 배치 문제를 이산 입자 군집 최적화 (DPSㅇ,discrete particle swarm optimization)를 이용하여 해를 구할 때 DPSO에 포함되어야 하는 이산화 단계를 위한 하이브리드 이산화 기법의 적용에 대하여 논한다. 이를 위해 PSO 반복단계에서 목적 함수 값과 최적화 속도를 입력 파라미터로 하는 규칙 기반 전문가 시스템을 제안하고 이산 변수를 포함하여 표현되는 PV 시스템 배치 문제의 최적해를 구하는 데 적용하였다. 다수준 이산화를 위하여 간단한 라운딩과 sigmoid 함수를 이용한 3단계 및 5단계 이산화 기법을 하이브리드 형태로 적용하였다. 규칙 기반 전문가 시스템을 적용하여 각 PSO 과정에서 적절한 이산화 기법을 선택함으로써 기존의 DPSO보다 좋은 성능의 최적화가 가능하도록 하였다. This paper discusses the application of a hybrid discretiziation method for the discretization procedure that needs to be included in discrete particle swarm optimization (DPSO) for the problem of allocating PV (photovoltaic) systems onto distribution power systems. For this purpose, this paper proposes a rule-based expert system considering the objective function value and its optimizing speed as the input parameters and applied it to the PV allocation problem including discrete decision variables. For multi-level discretization, this paper adopts a hybrid method combined with a simple rounding and sigmoid funtion based 3-step and 5-step quantization methods, and the application of the rule based expert system proposing the adequate discretization method at each PSO iteration so that the DPSO with the hybrid discretization can provide better performance than the previous DPSO.