Chance-constrained Scheduling of Variable Generation and Energy Storage in a Multi-Timescale Framework

Wen-Shan Tan,Md Pauzi Abdullah,Mohamed Shaaban 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.5

This paper presents a hybrid stochastic deterministic multi-timescale scheduling (SDMS) approach for generation scheduling of a power grid. SDMS considers flexible resource options including conventional generation flexibility in a chance-constrained day-ahead scheduling optimization (DASO). The prime objective of the DASO is the minimization of the daily production cost in power systems with high penetration scenarios of variable generation. Furthermore, energy storage is scheduled in an hourly-ahead deterministic real-time scheduling optimization (RTSO). DASO simulation results are used as the base starting-point values in the hour-ahead online rolling RTSO with a 15-minute time interval. RTSO considers energy storage as another source of grid flexibility, to balance out the deviation between predicted and actual net load demand values. Numerical simulations, on the IEEE RTS test system with high wind penetration levels, indicate the effectiveness of the proposed SDMS framework for managing the grid flexibility to meet the net load demand, in both day-ahead and real-time timescales. Results also highlight the adequacy of the framework to adjust the scheduling, in real-time, to cope with large prediction errors of wind forecasting.

Fault Diagnosis Model Based on Multi-level Information Fusion for CNC Machine Tools

Wen Yan,Tan Ji-wen,Zhan Hong,Sun Xian-bin 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8

The difficulty of CNC machine tools fault diagnosis is bigger than other general equipments because of the complex structure and the coupling among subsystems. The fault diagnosis model based on multi-level information fusion and hybrid intelligence is studied to improve reliability of fault diagnosis. Information from built-in sensors is used to monitor the status of CNC machine tools. The diagnosis principles of internal parameters-motor current, torque, temperature and following error are analyzed. Internal information and external sensors are two main sources which provide data to diagnosis. In order to detect effective fault signal, features of time domain, frequency domain and time-frequency domain are extracted. All these features constitute the feature set. The features are selected by the method of Kernel Principal Component Analysis (KCPA). Then the sensitive feature set is obtained. The method of multiple classifier fusion based on fuzzy comprehensive evaluation is researched. The determination method of weight based on information entropy is proposed. This diagnosis model has been tested feed system mechanical fault diagnosis of CNC machine tools and the results show which is effective and versatile.

Zero-Correlation Linear Cryptanalysis of Reduced Round ARIA with Partial-sum and FFT

( Wen-tan Yi ),( Shao-zhen Chen ),( Kuan-yang Wei ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.1

Block cipher ARIA was first proposed by some South Korean experts in 2003, and later, it was established as a Korean Standard block cipher algorithm by Korean Agency for Technology and Standards. In this paper, we focus on the security evaluation of ARIA block cipher against the recent zero-correlation linear cryptanalysis. In addition, Partial-sum technique and FFT (Fast Fourier Transform) technique are used to speed up the cryptanalysis, respectively. We first introduce some 4-round linear approximations of ARIA with zero-correlation, and then present some key-recovery attacks on 6/7-round ARIA-128/256 with the Partial-sum technique and FFT technique. The key-recovery attack with Partial-sum technique on 6-round ARIA-128 needs 2^123.6 known plaintexts (KPs), 2¹²¹encryptions and 2^90.3 bytes memory, and the attack with FFT technique requires 2^124.1KPs, 2^121.5 encryptions and 2^90.3 bytes memory. Moreover, applying Partial-sum technique, we can attack 7-round ARIA-256 with 2^124.6KPs, 2^203.5 encryptions and 2¹⁵² bytes memory and 7-round ARIA-256 employing FFT technique, requires 2^124.7KPs, 2^209.5 encryptions and 2¹⁵² bytes memory . Our results are the first zero-correlation linear cryptanalysis results on ARIA.

Multidimensional Differential-Linear Cryptanalysis of ARIA Block Cipher

Wen-Tan Yi,Jiongjiong Ren,Shao-Zhen Chen 한국전자통신연구원 2017 ETRI Journal Vol.39 No.1

ARIA is a 128-bit block cipher that has been selected as a Korean encryption standard. Similar to AES, it is robust against differential cryptanalysis and linear cryptanalysis. In this study, we analyze the security of ARIA against differential-linear cryptanalysis. We present five rounds of differential-linear distinguishers for ARIA, which can distinguish five rounds of ARIA from random permutations using only 284.8 chosen plaintexts. Moreover, we develop differential-linear attacks based on six rounds of ARIA-128 and seven rounds of ARIA-256. This is the first multidimensional differential-linear cryptanalysis of ARIA and it has lower data complexity than all previous results. This is a preliminary study and further research may obtain better results in the future.

Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistula via Radial Artery and Median Cubital Vein

Wen Nian Tan,Arvin Rajadurai,Dhayal Balakrishnan 대한신경중재치료의학회 2021 Neurointervention Vol.16 No.2

Cavernous sinus dural arteriovenous fistula (CS-DAVF) is an arteriovenous shunt where there is fistulous blood flow from the dural arteries from the internal or external carotid artery into the cavernous sinus. The current mainstay of therapy is endovascular treatment. We present a case of restrictive type of CS-DAVF in a 75-year-old male who presented with right eye symptoms. He was treated with embolisation using trans-radial artery access for angiographic runs and a median cubital vein access navigating into the cavernous sinus for coil deployment. This technique completely avoids the conventional technique of a femoral approach and confines all access to the arm. Therefore, there are less risks and complications associated with an arm access, improves patients’ comfort and mobility post procedure. Transradial artery and cubital vein access allows for a safe and convenient alternative technique using the arm as compared with conventional transfemoral approach for treatment of CS-DAVF.

Poster Session : Model Organisms and Disease ; Deletion mutagenesis of hepatitis B surface antigen with BAL31 exonuclease

( Wen Siang Tan ),( Beng Ti Tey ) 한국생화학분자생물학회 (구 한국생화학회) 2007 생화학분자생물학회 춘계학술발표논문집 Vol.2007 No.-

Recyclable and biocompatible microgel-based supporting system for positive 3D freeform printing of silicone rubber

Tan Wen See,Shi Qian,Chen Shengyang,Bin Juhari Muhammad Aidil,Song Juha 대한의용생체공학회 2020 Biomedical Engineering Letters (BMEL) Vol.10 No.4

Additive manufacturing (AM) of biomaterials has evolved from a rapid prototyping tool into a viable approach for the manufacturing of patient-specific implants over the past decade. It can tailor to the unique physiological and anatomical criteria of the patient’s organs or bones through precise controlling of the structure during the 3D printing. Silicone elastomers, which is a major group of materials in many biomedical implants, have low viscosities and can be printed with a special AM platform, known as freeform 3D printing systems. The freeform 3D printing systems are composed of a supporting bath and a printing material. Current supporting matrices that are either commercially purchased or synthesized were usually disposed of after retrieval of the printed part. In this work, we proposed a new and improved supporting matrix comprises of synthesized calcium alginate microgels produced via encapsulation which can be recycled, reused, and recovered for multiple prints, hence minimizing wastage and cost of materials. The dehydration tolerance of the calcium alginate microgels was improved through physical means by the addition of glycerol and chemical means by developing new calcium alginate microgels encapsulated with glycerol. The recyclability of the heated calcium alginate microgels was also enhanced by a rehydration step with sodium chloride solution and a recovery step with calcium chloride solution via the ion exchange process. We envisaged that our reusable and recyclable biocompatible calcium alginate microgels can save material costs, time, and can be applied in various freeform 3D printing systems.

Comparative Evaluation of Three Purification Methods for the Nucleocapsid Protein of Newcastle Disease Virus from Escherichia coli Homogenates

Tan Yan Peng,Ling Tau Chuan,Yusoff Khatijah,Tan Wen Siang,Tey Beng Ti The Microbiological Society of Korea 2005 The journal of microbiology Vol.43 No.3

In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with $Ni^{2+}$ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was $1.26\%$ and $5.56\%$, respectively. It was demonstrated that EBA achieved the highest final protein yield of $9.6\%$ with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.

Chance-constrained Scheduling of Variable Generation and Energy Storage in a Multi-Timescale Framework

Tan, Wen-Shan,Abdullah, Md Pauzi,Shaaban, Mohamed The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.5

This paper presents a hybrid stochastic deterministic multi-timescale scheduling (SDMS) approach for generation scheduling of a power grid. SDMS considers flexible resource options including conventional generation flexibility in a chance-constrained day-ahead scheduling optimization (DASO). The prime objective of the DASO is the minimization of the daily production cost in power systems with high penetration scenarios of variable generation. Furthermore, energy storage is scheduled in an hourly-ahead deterministic real-time scheduling optimization (RTSO). DASO simulation results are used as the base starting-point values in the hour-ahead online rolling RTSO with a 15-minute time interval. RTSO considers energy storage as another source of grid flexibility, to balance out the deviation between predicted and actual net load demand values. Numerical simulations, on the IEEE RTS test system with high wind penetration levels, indicate the effectiveness of the proposed SDMS framework for managing the grid flexibility to meet the net load demand, in both day-ahead and real-time timescales. Results also highlight the adequacy of the framework to adjust the scheduling, in real-time, to cope with large prediction errors of wind forecasting.

Methyl jasmonate induced responses in four plant species and its effect on Spodoptera litura Fab. performance

Ching-Wen Tan,Shaw-Yhi Hwang,Ju-Che Lo,Jitendra Yadav,Kaliova Tavou Ravuiwasa 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.3

Defensive proteins, such as polyphenol oxidase (PPO) and trypsin inhibitor (TI), are induced by herbivore wounding and exogenous methyl jasmonate application in various plant species. This study was conducted to measure induction of PPO and TI in radish, sweet pepper, tomato, and water spinach plants following herbivore wounding (I), methyl jasmonate application (M), and a combination of the two treatments (M+I). The effect of induced responses was also examined against third instar Spodoptera litura Fab. PPO activity was induced in radish by treatment I only; in sweet pepper, by treatments I and M; in tomato, by treatments I, M,and M+I; and in water spinach, by treatments M and M+I. The activity of TI was enhanced 1.2–1.4-fold in radish, sweet pepper, and tomato by M and M+I treatments, whereas in water spinach, it was enhanced 1.2-fold by all 3 treatments. The relative growth rate (RGR) of S. litura was reduced by 53% on radish plants following M treatment only. It was reduced by 37% and 42% on sweet paper plants following M and M+I treatment, respectively. RGR was significantly reduced on test tomato plants following I, M, and M+I treatments. The RGR of S. litura was unaffected on water spinach plants following any treatment. Collectively,the results of this study indicated that induction of plant defensive proteins in response to S. litura feeding or exogenous methyl jasmonate application varied among plant species, which further affected the induced plant resistance to the caterpillars.