• 한국물환경학회지
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• 제28권1호
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• pp.109-114
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• 2012

In this study, both sedimentation and thickening experiments were conducted for residuals produced from an advanced water treatment plant for more accurate and practical design of residual treatment train. In order to design a backwashed residual sedimentation basin (SRSB) in the filter backwash water recycle system, two kinds of backwash waters, one from sand filter (SFBW) and the other from GAC adsorption bed (GACBW), were separately collected and their surface loading rate measured. In addition, in order to design a gravity thickener, batch thickening tests were conducted for concentrated residuals taken from sedimentation basin and their limiting solid flux ($SF_{L}$) measured. From the experimental results and consideration of the seasonal characteristics of the residual, surface loading rate of $70m^{3}/m^{2}{\cdot}d$ was proposed as a design parameter for SRSB and solid loading rate of 20 kg $TS/m^{2}{\cdot}d$ was proposed as a design parameter for gravity thickeners. Finally, the material mass-balance was made for the design of each unit process in the residual treatment train.

• 설비공학논문집
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• 제3권4호
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• pp.215-221
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• 1991

Laminar film condensation of a saturated vapor in forced flow over a flat plate is analyzed by using integral method. Laminar condensate film is so thin that the inertia and thermal convection terms in liquid flow can be neglected. Approximate solutions for water are presented and well agreed with the similarity solutions over the wide range of physical parameter, Cp1(Ts-Tw)/Pr.hfg. For the strong condensation case, it is found that magnitude of the interfacial shear stress at the liquid-vapor interphase boundary is approximately equal to the momentum transferred by condensation, i.e., ${\tau}_i{\simeq}\dot{m}(U_O-U_i)$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.5035-5048
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• 2016

Nano scale networks are futuristic networks deemed as enablers for the Internet of Nano Things, Body area nano networks, target tracking, anomaly/ abnormality detection at molecular level and neuronal therapy / drug delivery applications. Molecular communication is considered the most compatible communication technology for nano devices. However, connectivity in such networks is very low due to inter-symbol interference (ISI). Few research papers have addressed the issue of ISI mitigation in molecular communication. However, many of these methods are not adaptive to dynamic environmental conditions. This paper presents an enhancement over original Memory-1 ISI cancellation scheme using maximum likelihood estimation of a channel parameter (λ) to make it adaptable to variable channel conditions. Results of the Monte Carlo simulation show that, the connectivity (P_conn) improves by 28% for given simulation parameters and environmental conditions by using enhanced Memory-1 cancellation method. Moreover, this ISI mitigation method allows reduction in symbol time (Ts) up to 50 seconds i.e. an improvement of 75% is achieved.

• Journal of Community Nutrition
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• 제6권2호
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• pp.86-90
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• 2004

This study was designed to assess the iron nutritional status and anemia of middle school girls in Ulsan City, who were evaluated with a questionnaire, measurement of hematological indices. The average height and weight of respondents were 154.81$\pm$6.28cm and 48.51$\pm$8.80kg, respectively. Mean daily energy intake was 1815.72$\pm$328.04kcal and iron intake was 15.13$\pm$4.50mg. The average hemoglobin concentration of subjects was 11.98$\pm$0.78g/dl, and the average hematocrit level was 36.62$\pm$2.21%. Transferrin saturationTS (%) was 25.58$\pm$9.82%, and the ferritin level was 40.45$\pm$23.03ng/ml. Iron deficiency anemia among the subjects was estimated as 54.2% by using hemoglobin(<12g/이), 33.9% by hematocrit (<36%). The clinical symptoms relating anemia were measured with 4 Likert scale (1 : never, 4 : often), 'tired out easily (2.34$\pm$0.92)' was the highest, followed by 'feel dizzy always (2.26$\pm$0.85)', 'decreasing ability to concentrate (2.23$\pm$0.77)', 'get a cold easily (2.19$\pm$0.82)', 'have a headache (2.10$\pm$0.79)', 'poor memory (2.09$\pm$0.83)', 'no appetite (1.99$\pm$0.85)', As for the correlation between iron parameter and clinical symptoms related to anemia, the hematocrit rate was negatively correlated with 'get a cold easily', 'pale face', 'feeling blue', 'difficult digestion' (p<0.05). The level of iron was negatively correlated with 'tired out easily', 'get a cold easily' (p<0.05) and TS (%) were negatively correlated with 'tired out easily (p<0.05)', 'get a cold easily (p<0.01). Our study resulted that the prevalence of a iron deficiency of a middle school girl is very high, therefore the guidelines for iron supplementation and nutritional education to improve their iron status should be provided.

• 한국지능시스템학회논문지
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• 제22권3호
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• pp.267-272
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• 2012

본 논문에서는 6 방향 자유도를 지닌 능동 자기베어링 시스템의 강인 디지털 퍼지 제어에 대한 내용을 다루고자 한다. 6방향 자유도에 대한 기본 모델은 회전자 구조와 원뿔형의 능동 자기베어링 시스템의 자기력 간의 상관관계에 의해 결정된다. 구성된 모델은 비선형 동적방정식으로 구성되기 때문에, 제어 목적을 달성하기 위한 제어 입력 신호의 설계가 어려우며, 외부 환경의 영향에 따른 시스템 파라미터 변화율에도 많이 민감한 편이다. 이를 보완하기 위하여, 획득한 동적방정식을 기반으로 TS 퍼지 모델에 기반 한 디지털 제어 목적에 적합한 구조로의 변환이 이루어진다. 여기서 말하는 제어 목적이란, 회전자의 회전을 외부의 물리적 접촉 없이 자기장의 힘만으로 동작하도록 베어링의 위치를 최대한 센터에 위치케 하는 것을 말한다. 본 논문에서는 6자유도를 지닌 능동 자기베어링 시스템의 비선형성에 대한 해석 방안으로 퍼지 모델링을 통해 시스템을 재해석하게 되며, 외부 파라미터 변화에 따른 대응을 위하여 강인 제어기 설계를 목적으로 한다. 제안된 강인 제어 알고리즘은 시뮬레이션 과정을 통해 검증된다.

• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.897-901
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• 2011

This paper presents a TS (Takagi-Sugeno) type FLC (Fuzzy Logic Controller) with only 3 rules. The choice of parameters of FLC is very difficult job on design FLC controller. Therefore, the choice of appropriate linguistic variable is an important part of the design of fuzzy controller. However, since fuzzy controller is nonlinear, it is difficult to analyze mathematically the affection of the linguistic variable. So this choice is depend on the expert's experience and trial and error method. In the design of the system, we use a variety of response characteristics like stability, rising time, overshoot, settling time, steady-state error. In particular, it is important for a stable system design to predict the steady-state error because the system's steady-state response of the system is related to the overall quality. In this paper, we propose the method to choose the consequence linear equation's parameter of T-S type FLC in the view of steady-state error. The parameters of consequence linear equations of FLC are tuned according to the system error that is the input of FLC. The full equation of T-S type FLC is presented and using this equation, the relation between output and parameters can represented. As well as the FLC parameters of consequence linear equations affect the stability of the system, it also affects the steady-state error. In this study, The system according to the parameter of consequence linear equations of FLC predict the steady-state error and the method to remove the system's steady-state error is proposed using the prediction error value. The simulation is carried out to determine the usefulness of the proposed method.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.32-40
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• 2020

While the utilization of wood as a raw material in related industries has been increasing with the population increasing, the availability of wood from natural forests has continued to decline. An alternative to this situation is the manufacture of particleboard from non-wood lignocellulose materials through the modification of sandwich particleboard (SPb) using bamboo strands as reinforcement. In this study, strandsof belangke bamboo (Gigantochloa pruriens W) and tali bamboo (Gigantochloa apus) were utilized. The non-wood particles included sugar palm fibers, cornstalk, and sugarcane bagasse. The board was made in a three-layer composition of the face, back, and core in a ratio of 1: 2: 1. The binder used was 8% isocyanate resin. The sheet was pressed at a temperature of 160℃ for 5 min under a pressure of 3.0 N/㎟. Testing included physical and mechanical properties based on the JIS A 5908 (2003) standard, while acoustic testing was based on ISO 11654 (1997) standards. The results showed that using bamboo strands as reinforcement has an effect on the mechanical and physical properties of SPb. Almost all the types of boards met the JIS A 5908 (2003) standards, with the exception of thickness swelling (TS) and internal bond (IB) parameters. Based on the thickness swelling parameter, the C-type board exhibited the best properties. Overall, the B-type board thatused a belangke bamboo strand for the surface and sugarcane bagasse as the core underwent the best treatment. Based on the acoustical parameter, boards using a tali bamboo strand for the surface and sugar palm fiber as the core (E-type board) exhibited good sound absorption properties.

• Wind and Structures
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• 제18권3호
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• pp.281-294
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• 2014

There are several parameters affecting the response of industrial reinforced concrete (RC) chimneys, i.e., the severity of wind and earthquake loads acting to the structure, structural properties such as height and cross section of the chimney, the slenderness property of the structure etc. One of the most important parameter that should be considered while understanding the wind response of industrial RC chimneys is slenderness property. Although there is no certain definition for slenderness effect on these structures, some standards like ASCE-7 define slenderness from different aspects of the structural properties. In the first part of this study, general information about the definition of slenderness in the well-known standards and ten selected industrial RC chimneys are given. In the second part of the study, brief information about wind load standards that are used for calculating wind loads namely ACI 307/98, CICIND 2001, DIN 1056, TS 498 and Eurocode 1 is given. In the third part of the study, calculated wind loads for selected chimneys are represented. In the fourth part of this study, the internal forces obtained from load combinations that are applied to chimneys and some graphs presenting the effect of slenderness on chimneys are given. In the last part of the study, a conclusion and discussion part is taking place.

• 한국생활과학회지
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• 제18권3호
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• pp.749-756
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• 2009

Keeping abreast with the latest consumer's trends, industries are focusing on sensibility aspects of products to meet consumer's needs. The car(?) seat cover fabrics are more closely related to human senses than anything else. This study attempted to investigate which seat cover fabric can give good feeling to consumers and to analyze their characteristics. Twelve kinds of jacquard fabric used for seat cover were selected. The Kawabata Evaluation System was used to measure the mechanical properties of 12 jacquard fabrics, and tactile sensibility(TS), and preference(P) determined by subjective evaluation of 160 participants were also utilized. The stepwise regression analysis was made to select the most significant mechanical properties, and some models for predicting tactile sensibility and preference was developed. The results are briefly summarized as follows: the most important parameter to choose seat cover fabric is a "hygienic property" and the other parameters are 'materials with color fastness', 'compressive property', 'color', 'antibacterial property', 'easy-care property'. The LogSMD, LogB, LC, EM were selected as significant mechanical properties affecting tactile sensibility. Also, the LC, LogB, LogSMD, LogWC, LogMMD were selected as significant mechanical properties affecting preference.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권8호
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• pp.423-431
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• 2000

This paper presents a systematic approach to the input-output data-based fuzzy modeling for the complex and uncertain nonlinear systems, in which the conventional mathematical models may fail to give the satisfying results. To do this, we propose a new method that can yield a successful fuzzy model using a mGA hybrid schemes with a fine-tuning method. We also propose a new coding method fo chromosome for applying the mGA to the structure and parameter identifications of fuzzy model simultaneously. During mGA search, multi-purpose fitness function with a penalty process is proposed and adapted to guarantee the accurate and valid fuzzy modes. This coding scheme can effectively represent the zero-order Takagi-Sugeno fuzzy model. The proposed mGA hybrid schemes can coarsely optimize the structure and the parameters of the fuzzy inference system, and then fine tune the identified fuzzy model by using the gradient descent method. In order to demonstrate the superiority and efficiency of the proposed scheme, we finally show its applications to two nonlinear systems.