Browsing by Issue Date, starting with "2008-07-28"

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Effects of water and methanol on the molecular organization of 1-butyl-3-methylimidazolium tetrafluoroborate as functions of pressure and concentration
(2008-07-28)
Chang, Hai-Chou
;
Jiang, Jyh-Chiang
;
Liou, You-Chang
;
Hung, Chao-Hsin
;
Lai, Ting-Yun
The structural organization in mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)])/water or methanol was studied by infrared spectroscopy. No drastic change in the concentration dependence of the alkyl C-H band frequency was observed at high concentration of the ionic liquid. This behavior indicates a clustering of the ionic liquid in alkyl regions. Nevertheless, the presence of methanol significantly perturbs the ionic liquid-ionic liquid associations in the imidazolium region. On the basis of the responses to change in pressure and concentration, two different types of O-H species, i.e., free O-H and bonded O-H, were observed in the O-H stretching region. For [bmim][BF(4)]/water mixtures, the compression leads to loss of the free O-H band intensity. It is likely that free O-H is switched to bonded O-H as high pressures are applied. For [bmim][BF(4)]/methanol mixtures, the free O-H is still stable under high pressures. (C) 2008 American Institute of Physics.
Specific DNA extraction through fluid channels with immobilization of layered double hydroxides on polycarbonate surface
(2008-07-28)
Chan, Chia-Hao
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Chen, Jem-Kun
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Chang, Feng-Chih
;
應用化學系
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Department of Applied Chemistry
The purpose of this study was to immobilize inorganic layered double hydroxides (LDHs) on the polycarbonate (PC) substrate as the media to extract the specific DNA molecules through fluidic system and to enhance the extraction efficiency of specific DNA molecules from extreme low concentration in sample solution. LDH immobilized through solvent swelling and plasma treatment on the polymer surface captured the specific DNA molecules lysed from Escherichia coli (E. call) cells as the target DNA molecules with 2 x 10(-4) g/l of concentration in sample solution mixed biomacromolecules lysed from human blood. The encapsulated DNA molecules released through dissolve of LDHs by slight acid (pH 4-5) solution then amplified by polymerase chain reaction (PCR) process through the primers for E coli cells. The DNA molecules amplified by PCR process were characterized by gel electrophoresis to recognize the existence of E. coli cells. The results show that immobilized LDHs could be regarded as the specific DNA detector in the sample solution mixed biomacromolecules for rapid disease diagnosis through fluidic system to approach the lab-on-a-chip (LOC). (c) 2008 Elsevier B.V. All rights reserved.
Characterization of the low temperature activated N(+)/P junction formed by implant into silicide method
(2008-07-30)
Chang, Kow-Ming
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Lin, Jian-Hong
;
Yang, Chih-Hsiang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Shallow junction formation and low thermal budget control are important for advanced device manufacturing. Implant into silicide (IIS) method is a candidate to achieve both requirements. In this work we show that the high activation ability of the implant into nickel silicide method at low activated temperature is strongly related to the solid phase epitaxial regrowth (SPER) process. The SIMS, capacitance-voltage (C-V), four points probe (FPP), and current-voltage (I-V) measurements are combined to demonstrate that the SPER process of the IIS method is starting from the silicide/silicon (M/S) interface. The best N(+)/P interface is formed when SPER is complete. After SPER process finished, additional thermal budget may cause junction performance degradation at the temperature higher than 550 degrees C. (C) 2008 Elsevier B. V. All rights reserved.
Identifying groundwater pumping source information using simulated annealing
(2008-07-30)
Lin, Yu-Chung
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Yeh, Hund-Der
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環境工程研究所
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Institute of Environmental Engineering
This study develops an approach referred to as SA-MF using simulated annealing (SA) and a three-dimensional groundwater flow model (MODFLOW-2000) to determine the pumping source information, namely the pumping source location, the pumping rate and the pumping period. Eight scenarios, each with various cases for aquifers with homogeneous or heterogeneous conductivities, are used to test the applicability and accuracy of SA-MF in determining the pumping source information. The results show that at least five measured heads should be used to analyse the pumping source identification problem and at least three observation wells are required to effectively determine the pumping source information. The SA-MF gives good estimated results in both synthetic and real problems even if the measured heads contain measurement errors. Copyright (C) 2008 John Wiley & Sons, Ltd.
The effects of plasma treatment on the thermal stability of HfO(2) thin films
(2008-07-30)
Chang, Kow-Ming
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Chen, Bwo-Ning
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Huang, Shih-Ming
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The thermal stability of pure HfO(2) thin films is not high enough to withstand thermal processes, such as S/D activation or post-metal annealing, in modern industrial CMOS production. In addition, plasma nitridation technology has been employed for increasing the dielectric constant of silicon dioxide and preventing boron penetration. In this experiment, atomic layer deposition (ALD) technology was used to deposit HfO(2) thin films and inductively coupled plasma (ICP) technology was used to perform plasma nitridation process. The C-V and J-V characteristics of the nitrided samples were observed to estimate the effect of the nitridation process. According to this study, plasma nitridation process would be an effective method to improve the thermal stability of HfO(2) thin films. (C) 2008 Elsevier B. V. All rights reserved.
An analytical method of stage-fall-discharge rating
(2008-07-30)
Wu, Reuy-Bean
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Yang, Jinn-Chuang
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土木工程學系
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Department of Civil Engineering
This paper presents an analytical method for establishing a stage-fall-discharge rating using hydraulic performance graphs (HPG). The rating curves derived from the HPG are used as the basis to establish the functional relation of stage, fall and discharge through regression analysis following the USGS procedure. In doing so, the conventional trial-and-error process can be avoided and the associated uncertainties involved may be reduced. For illustration, the proposed analytical method is applied to establish stage-fall-discharge relations for the Keelung River in northern Taiwan to examine its accuracy and applicability in an actual river. Based on the data extracted from the HPG for the Keelung River, one can establish a stage-fall-discharge relation that is more accurate than the one obtained by the conventionally used relation. Furthermore, the discharges obtained from the proposed rating method are verified through backwater analysis for measured high water level events. The results indicate that the analytical stage-fall-discharge rating method is capable of circumventing the shortcomings of those based on single-station data and, consequently, enhancing the reliability of flood estimation and forecasting. Copyright (C) 2008 John Wiley & Sons, Ltd.
Characterization of the low temperature dopant activation behavior at NiSi/silicon interface formed by implant into silicide method
(2008-07-30)
Chang, Kow-Ming
;
Lin, Jian-Hong
;
Sun, Cheng-Yen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Process temperature and thermal budget control are very important for high-k dielectric device manufacturing. This work focuses on the characteristics of low temperature activated nickel silicide/silicon (M/S) interface formed by implant into silicide (IIS) method. By combining SIMS, C-V, I-V, and AFM measurements in this work, it provides a clear picture that the high dopant activation ratio can be achieved at low temperature (below 600 degrees C) by IIS method. From SIMS and C-V measurements, high dopant activation behavior is exhibited, and from I-V measurement, the ohmic contact behavior at the M/ S junction is showed. AFM inspection displays that under 2nd RTA 700 degrees C 30 s no agglomeration occurs. These results suggest that IIS method has the potential to integrate with high-k dielectric due to its low process temperature. It gives an alternate for future device integration. (C) 2008 Elsevier B. V. All rights reserved.
Design and implementation of electronic toll collection system based on vehicle positioning system techniques
(2008-07-30)
Lee, Wei-Hsun
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Tseng, Shian-Shyong
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Wang, Ching-Hung
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資訊工程學系
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Department of Computer Science
Currently, most electronic toll collection (ETC) systems around the world are implemented by DSRC (dedicated short range communication) technology. However, area wide integrated MLFF (multilane free flow) road charging system is now currently on its development to replace DSRC-based ETC systems. VPS (vehicle positioning system) based ETC system is a category of location based service which tolls vehilces by determining if they move into the charging zone. It is an evolutional technology for area wide integrated road charging solution, which achieves the goal of electronic payment or electronic toll collection by a totally different scheme comparing to traditional DSRC-based technology. In this paper, the design and implementation of VPS-based ETC system is detailedly discussed, and a debit transaction VPS system field test had been practiced in the freeway of Taiwan. (C) 2008 Elsevier B.V. All rights reserved.
Carrier gas effects on the SiGe quantum dots formation
(2008-07-30)
Lee, C. -H.
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Yu, C. -Y.
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Lin, C. M.
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Liu, C. W.
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Lin, H.
SiGe quantum dots (QDs) grown by ultra-high vacuum chemical vapor deposition using H(2) and He carrier gases are investigated and compared. SiGe QDs using He carrier gas have smaller dot size with a better uniformity in terms of dot height and dot base as compared to the H(2) carrier gas. There is a higher Ge composition and less compressive strain in the SiGe QDs grown in He than in H(2) as measured by Raman spectroscopy. The Ge content is higher for He growth than H(2) growth due to hydrogen induced Si segregation and the lower interdiffusivity caused by the more strain relaxation in the He-grown SiGe dots. The photoluminescence also confirms more compressive strain for H(2) growth than He growth. Hydrogen passivation and Ge-H cluster formation play an important role in the QDs growth. (C) 2008 Elsevier B. V. All rights reserved.
Design of low-voltage CMOS low-noise amplifier with image-rejection function
(2008-07-31)
Wei, L. -S.
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Wu, H. -I.
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Jou, C. F.
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電信工程研究所
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Institute of Communications Engineering
A new design is presented that combines a low-noise amplifier (LNA) with an on-chip. lter instead of external. lter to eliminate image signal based on TSMC 0.18 mu m CMOS technology. The fully integrated 5.9 GHz LNA exhibits 15.2 dB gain, 3.2 dB noise figure, better than -15 dB input and output return loss, and -27 dB image rejection. The circuit operates at a supply voltage of 1 V and consumes only 6.1 mW power.
Pre-charge sample-and-hold circuit
(2008-07-31)
Wu, Jieh-Tsorng
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Lee, Zwei-Mei
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Wang, Cheng-Yeh
A precharge sample-and-hold circuit is formed by coupling a buffer with an input port and making use of a switch to conduct the circuit between the buffer and a total load capacitor for precharging according the state of a sample-and-hold circuit. When the sample-and-hold circuit is in the sample mode, it precharges the total load capacitor. When the sample-and-hold circuit is in the hold mode, the influence to the sampled signal is further reduced due to the precharging. The requirements of swing rate, output voltage swing, gain-bandwidth product for the opamps can therefore be reduced, hence being applicable to the realization of the design of advanced fabrication technologies of low supply voltages.
SELF-CALIBRATING HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER
(2008-07-31)
SU, CHAU-CHIN
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LU, HUNG-WEN
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CHI, SHUN-MIN
A precisely self-calibrating high-speed analog to digital converter is disclosed, wherein the aspect ratios of tri-state inverters are adjusted to fine-tune threshold voltage as comparators. And the multiplexers composed of tri-state inverters amplify the signal from the output of comparators. Their switches of tri-state inverters may be properly controlled to select the optimal channels and reduce unnecessary power consumption. The calibration circuitry utilizes under-sampling to calculate the duty cycles of comparators, selecting the optimal comparators and channels. By the way, the invention may avoid process variation.
用於通訊系統的資料交換裝置及方法
(2008-08-01)
李鎮宜
;
陸志豪
;
林建青
;
張錫嘉
;
許雅三
一種用於通訊系統之資料交換裝置及方法,其主要係由一轉換電路接收一具有實際編碼尺寸的來源資料,以轉換為一具有容許編碼尺寸的轉換資料,藉由在轉換資料中設置判別位元來標示是否為來源資料。之後由一位移電路對轉換資料進行一位移量的位移以產生一位移資料,並由位移資料的最低位元及最高位元開始擷取實際編碼尺寸分別作為一第一資料及一第二資料,或者在第一資料的擷取方式上,改為由最高位元減去實際編碼尺寸的位元作為第一資料的起始位元,以從最低位元的方向擷取實際編碼尺寸。最後使用一比較及選擇電路比較第一資料及第二資料中相對應的判別位元,以輸出一輸出資料,其中輸出資料係來源資料位移了上述的位移量後的資料。
Synthesis and characterization of nanoporous SiO2/pHEMA biocomposites
(2008-08-01)
Liu, Yen-Yu
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Liu, Tse-Ying
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Chen, San-Yuan
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Liu, Dean-Mo
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材料科學與工程學系
Porous SiO2/pHEMA biocomposites were synthesized in situ by incorporating silica nanoparticles with a hydroxyethyl methacrylate (HEMA) monomer, following a UV-induced photopolymerization. The nanostructure of the composites was characterized and the resulting physical properties were examined. The release kinetics of the model molecule-vitamin B12-and the hemocompatibility of the porous SiO2/pHEMA composites were investigated. Heterogeneous reaction kinetics is proposed to be the formation mechanism of the nanoporosity in the pHEMA matrix as a result of incorporating silica nanoparticles following photopolymerization. Experimental results also demonstrated that the incorporation of the silica nanoparticles into the pHEMA matrix not only enhanced the mechanical property but also maintained a good hemocompatibility of the resulting biocomposites. In addition, it was observed that the drug release profile of the composites (in the form of a membrane) can be precisely regulated from a two-stage pattern to one-stage pattern by varying the concentration of both the SiO2 nanoparticles and HEMA monomer during synthesis. The permeability of the model drug was enhanced by two orders of magnitude from 4.22 x10(-7) cm(2)/h to 3.92 x 10(-5) cm(2)/h by controlling the micro-to-nanostructure of the composites. The platelet adhesion experiment demonstrated low aggregation of the platelets on the surface of the biocomposite membranes, indicating a promising antithrombotic property.
Robust design for multiple dynamic quality characteristics using data envelopment analysis
(2008-08-01)
Tong, Lee-Ing
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Wang, Chun-Ho
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Tsai, Chih-Wei
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工業工程與管理學系
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Department of Industrial Engineering and Management
The Taguchi method is extensively adopted in various industries to continuously improve product design in response to customer requirements. The dynamic system of the Taguchi method is frequently implemented to design products with flexible applications. However, Taguchi v dynamic system can be employed only for individual quality characteristic, and the relationship between the quality characteristic and the signal factor is assumed to be linear. Because of these restrictions, Taguchi's dynamic system is ineffective for multiple quality characteristics or when the quality characteristic has a nonlinear relationship with the signal factor. This study describes a novel procedure for optimizing a dynamic system based on data envelopment analysis. The proposed procedure overcomes the limitations of Taguchi's dynamic system. Two cases are analyzed to demonstrate the effectiveness of the proposed procedure. The results show that the proposed procedure can enhance multiple dynamic quality characteristics. Copyright (C) 2008 John Wiley & Sons, Ltd.
介面系統、方法及裝置
(2008-08-01)
陳登吉
;
彭士榮
;
蔣加洛
本發明係揭露一種介面系統、方法及裝置,適用於一電子裝置,其包含一載入模組、一指令資料庫、一巨集模組、一物件模組、一指令輸入模組及一處理模組。載入模組用以載入一辨識裝置及一應用軟體;指令資料庫,包含複數個動作指令,任一動作指令皆對應應用軟體之一操作動作;巨集模組用以設定複數個巨集指令,以執行應用軟體之一組操作動作,其中任一巨集指令皆對應一組動作指令;物件模組用以將應用軟體之相對位置設定為操作動作控制之操作物件;指令輸入模組連結辨識裝置,用以輸入辨識裝置辨識一動作訊號所產生之一輸入指令;處理模組根據輸入指令,從指令資料庫中取得相對應之動作指令,並於載入之應用軟體中執行動作指令相對應之操作動作。
High light output intensity of titanium dioxide textured light-emitting diodes
(2008-08-01)
Huang, K. C.
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Lan, W. H.
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Huang, K. F.
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Lin, J. C.
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Cheng, Y. C.
Higher light output intensity and wider polar radiation pattern of InGaN/GaN multiple quantum well (MQW) light-emitting diodes (LEDs) with a different nanoscale titanium dioxide (TiO2) textured densities film have been observed. The light output power values and external quantum efficiency of the conventional LEDs at an injection current of 20 mA are 6.34 mW and 11.7%, respectively. The light output power values and external quantum efficiency of the nanoscaled TiO2 textured LEDs at an injection current of 20 mA are 7.55 mW and 14%, respectively. The light output intensity and power values of the nanoscaled TiO2 textured LEDs is approximately 65% and 20% higher than that of the conventional LEDs, respectively. (C) 2008 Elsevier Ltd. All rights reserved.
Document recommendation for knowledge sharing in personal folder environments
(2008-08-01)
Liu, Duen-Ren
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Lai, Chin-Hui
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Huang, Chiu-Wen
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
Sharing sustainable and valuable knowledge among knowledge workers is a fundamental aspect of knowledge management. In organizations, knowledge workers usually have personal folders in which they organize and store needed codified knowledge (textual documents) in categories. In such personal folder environments, providing knowledge workers with needed knowledge from other workers' folders is important because it increases the workers' productivity and the possibility of reusing and sharing knowledge. Conventional recommendation methods can be used to recommend relevant documents to workers; however, those methods recommend knowledge items without considering whether the items are assigned to the appropriate category in the target user's personal folders. In this paper, we propose novel document recommendation methods, including content-based filtering and categorization, collaborative filtering and categorization, and hybrid methods, which integrate text categorization techniques, to recommend documents to target worker's personalized categories. Our experiment results Show that the hybrid methods Outperform the pure content-based and the collaborative filtering and categorization methods. The proposed methods not only proactively notify knowledge workers about relevant documents held by their peers, but also facilitate push-mode knowledge sharing. (C) 2007 Elsevier Inc. All rights reserved.
Tight-binding theory for coupling asymmetric photonic crystal waveguides
(2008-08-01)
Huang, Chih-Hsien
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Hsieh, LVen-Feng
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Cheng, Szu-Cheng
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光電工程學系
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Department of Photonics
The physical properties of asymmetric photonic-crystal directional couplers are studied under the tight-binding model, which assumes that the field distribution of photon ic-cryst al waveguides is localized around periodic defects. The couplings of nearby defects between two asymmetric waveguides cause two dispersion relations to split further whereas the couplings of nearby defects within an individual waveguide cause the sinusoidal modulations of the dispersion curves. The field-envelope distributions of the coupler are expressed by using the eigenmodes of the tightbinding equations and are consistent with the comparing results from finite-difference time-domain simulations.
Lasing Behavior, Gain Property, and Strong Coupling Effects in GaN-Based Vertical-Cavity Surface-Emitting Lasers
(2008-08-01)
Lu, Tien-Chang
;
Chu, Jung-Tang
;
Chen, Shih-Wei
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Cheng, Bo-Siao
;
Kuo, Hao-Chung
The optical properties of a GaN-based vertical-cavity surface-emitting laser (VCSEL) with two dielectric distributed Bragg reflectors were investigated under optically pumped operation. The laser emits blue-violet light at a wavelength of 414 nm at room temperature with a high spontaneous emission coupling factor (beta-factor) of 2 x 10(-2) and a linewidth of 0.25 nm. The optical gain was determined by the Hakki-Paoli method by measuring the photoluminescence spectra below threshold conditions. At room temperature, an optical gain of 2900 cm(-1) was obtained under threshold condition. The linewidth enhancement factor (alpha-factor) is estimated front the ratio of the wavelength and gain derivation with respect to the carrier density, and the alpha-factor at room temperature is estimated to be 2.8. Strong exciton-photon coupling in the microcavity was observed at room temperature. A 9 meV Rabi splitting with 60% peak-to-valley contrast was determined from the photoluminescence measurements. Emission spectra showing the evolution of anticrossing behavior were also observed.