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匹配条件: “ Yi-Chen Chen” ,找到相关结果约95632条。
On Maximum-Likelihood Detection for Non-coherent FH/BFSK in Multitone Jamming
Yi-Chen Chen
Journal of Computers , 2006, DOI: 10.4304/jcp.1.5.1-8
Abstract: We derive the optimum maximum-likelihood (ML) non-coherent detector for FH/BFSK systems in the environment of multitone jamming and additive white Gaussian noise with no aid of jamming state indication and the resultant signal-plus- jammer tone, which, however, were required in K. C. Teh’s previous work [1]. Because of the optimum ML detector’s huge complexity, a novel complexity-reduced scheme which is called joint-suboptimum maximum-likelihood (JSML) detector is proposed. Simulation results show the superiority of the proposed optimum ML and JSML detectors over other existing diversity combining approaches. The performance analysis in terms of bit error probability (BEP) for the JSML detector with single diversity in n = 1 and n = 2 band multitone jamming (BMJ) is provided and further validated by simulation results. In moderate and high SNR conditions, though the proposed JSML detector performs slightly worse than the optimum ML detector, it does achieve much complexity reduction.
實徵研究/家庭情境中的網路使用行為:多元面向的情境架構初探/陳怡蓁 │ Web-Using Behavior in Context of the Home Use Environment: Toward a Multidimensional Framework / Yi-Chen Chen
陳怡蓁 Yi-Chen Chen
Journal of Library and Information Science , 2008,
Abstract: 近年來,網際網路逐漸滲透人們的日常生活:在台灣,家中網路使用人口亦大幅增加,顯示我國民眾的家戶日常生活與網際網路之間已產生密切的關連。然 而,在過去的網路使用者行為相關研究中,較少以家庭為主要分析場域去討論家庭情境中的網路使用行為,因而引發本研究之動機。既然家戶是人們主要上網地點, 且家庭又是一個重要的社會互動單位;本文試圖將家庭視為一種資訊使用環境,從情境的概念來探索家庭網路使用環境下的情境面向,並且建立一個多元面向的情境 架構模式。 本研究採用文獻分析法,彙整國內外相關研究,特別是有關家庭網路使用之實證研究:藉由對相關文獻的分析,一方面描繪出一般家庭的網路使用現況,一方面也試圖歸納出家庭環境對於網路使用行為提供了哪些情境面向,進而建構一家庭使用環境下的情境架構。 言 研究結果發現,家庭作為資訊使用環境的情境層級,它既是實體空間環境,也是社會生活環境,提供人類資訊行為一組特定情境的面向:包含:環境本身的特性和社 會條件、環境中的空間配置、環境中的時間分配、環境中的參與成員、環境中的人際互動、以及環境中的資訊活動與需求。而且,這些面向並不是獨立運作的,是在 動態的框架中彼此產生關連。整體而言, As more people gain at-home access to the Internet, information behaviors on the Web has become embedded in everyday life. The objective of this study was to characterize the home as the context of information use environment level and to explore the framework of web-use behaviors in context at home. In this framework, the context of home use environment appears to be a multidimensional construct. In this paper, the author reviewed the literature and analyzed the empirical findings from Internet surveys, web user studies of the home environment, and information behavior studies of the context, etc. Based on the analysis, the author pointed out the multidimensional framework about the context of the home use environment. Findings indicated that the home provided a distinct information use environment beyond physical setting alone in which members used the Web for diverse purposes and interests. This framework is multidimensional, including the properties or conditions of the environment, space of the environment, time allocation of the environment, participants of the environment, social interaction of the environment, and information activities of the environment. A framework is being developed at present; however, future empirical research will be needed to determine the reliability of this finding. 頁次:81-92
E-Business Strategies in the Taiwan Automobile Industry-Case Studies Approach
JrJung Lyu,Yi-Chen Lin
International Journal of Electronic Business Management , 2003,
Abstract: Automobile industry in Taiwan has the characteristics of capital and technology intensive, strong operation management capability, close relationship supply chain and has played a critical role in the international market. Since there are hundreds of the first-tier suppliers and thousands of the second-tier suppliers, this leads automobile industry to be one of the most important industries in Taiwan. Besides setting up big R&D centers, aggressively participating international collaboration, and building up overseas plants to face up the challenge of globalization, many automobile manufacturers have adopted e-business strategy as a key driver to strengthen their competitive advantages. This research aims to analyze the e-business strategy and the implementation models of the automobile industry in Taiwan. Through a review of the global automobile industry e-business practice, possible e-business trends are discussed. Three representative cases, each with different e-business strategy and B2B EC project, are presented where an analysis framework is used to classify their implementation models. The results of this strategic analysis can be used to support the industry practitioners to develop their e-business strategies.
數位出版從業人員專業能力之研究 A Study on the Professional Competencies of the Employees Working in the Digital Publishing Industry
Shin Liao,Yi-Chen Pan
Journal of Educational Media & Library Sciences , 2010,
Abstract: 隨著數位出版逐漸成為下一波出版主流趨勢,傳統出版產業人才的培育也必須配合產業轉型,以加速出版產業之數位化,有鑑於此,本研究以數位出版產業為對象,探討數位出版產業從業人員所需具備之專業能力,以供傳統出版人員轉型時之參考。研究首先採用文獻探討方式,以瞭解數位出版產業之現況,再透過層級結構問卷發送,以FuzzyAHP層級分析法建構完整能力層級、指標。研究結果顯示:(1)數位版產業主要之職務可分為行銷企劃人員、內容製作人員、程式設計工程師三項。(2)數位出版從業人員所應具備之專業能力,共包含4大主要構面,7項能項目及32個能力指標。(3)數位出版產業對專業能力之需求,能力構面上,以「系統開發」能力權重值最高,而能力指標中以「瞭解數位檔案加密方式」權重值最高,同時也最為數位出版從業人員所需要。 This study explores what professional competencies that digital publishing industry employees must possess. The result is for traditional publishing employees’ reference when they have to make changes. In this study, a literature review was conducted to collect information on the current development of digital publishing industry. Through the Analytic Hierarchy Process (FAHP) questionnaires, this study constructs a complete competence hierarchy and indicators. At the end, conclusions were reached as follows :( 1) The main occupations in the digital publishing industry are marketing planners, content writers and programmers. (2) The professional competencies people in digital publishing must possess can be categorized into 4 dimensions, 7 competence categories and 32 competence indicators.(3) Considering the demand for professional competencies in digital publishing industry, System Development Competence Dimension is weighted the most. Among competence indicators, “knowing how to encrypt digital files” is most required by digital publishing employees.
Characterization of the Role of Tumor Necrosis Factor Apoptosis Inducing Ligand (TRAIL) in Spermatogenesis through the Evaluation of Trail Gene-Deficient Mice
Yi-Chen Lin, John H. Richburg
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0093926
Abstract: TRAIL (TNFSF10/Apo2L) is a member of the tumor necrosis factor (TNF) superfamily of proteins and is expressed in human and rodent testis. Although the functional role of TRAIL in spermatogenesis is not known, TRAIL is recognized to induce apoptosis via binding to its cognate receptors; DR4 (TRAIL-R1/TNFRSF10A) and DR5 (TRAIL-R2/TNFRSF10B). Here, we utilize Trail gene-deficient (Trail?/?) mice to evaluate the role of TRAIL in spermatogenesis by measuring testis weight, germ cell apoptosis, and spermatid head count at postnatal day (PND) 28 (pubertal) and PND 56 (adult). Trail?/? mice have significantly reduced testis to body weight ratios as compared to wild-type C57BL/6J at both ages. Also, Trail?/? mice (PND 28) show a dramatic increase in basal germ cell apoptotic index (AI, 16.77) as compared to C57BL/6J (3.5). In the testis of adult C57BL/6J mice, the AI was lower than in PND 28 C57BL/6J mice (2.2). However, in adult Trail?/? mice, the AI was still higher than that of controls (9.0); indicating a relative high incidence of germ cell apoptosis. Expression of cleaved caspase-8 (CC8) and cleaved caspase-9 (CC9) (markers of the extrinsic and intrinsic apoptotic pathway, respectively) revealed a two-fold increase in the activity of both pathways in adult Trail?/? mice compared to C57BL/6J. Spermatid head counts in adult Trail?/? mice were dramatically reduced by 54% compared to C57BL/6J, indicating these animals suffer a marked decline in the production of mature spermatozoa. Taken together, these findings indicate that TRAIL is an important signaling molecule for maintaining germ cell homeostasis and functional spermatogenesis in the testis.
Synthesis, Crystal Structure and Antimicrobial Activity of (E)-ethyl-4-(2-oxoacenaphthylen-1(2H)-ylideneamino) benzoate  [PDF]
Yi-Chen Chan, Abdussalam Salhin Mohamed Ali, Melati Khairuddean, Baharuddin Salleh
Journal of Crystallization Process and Technology (JCPT) , 2013, DOI: 10.4236/jcpt.2013.32011

A Schiff base, (E)-ethyl-4-(2-oxoacenaphthylen-1(2H)-ylideneamino)benzoate, (E4AB) had been synthesized in good yield by the acid-catalyzed condensation reaction of acenaphthenequinone and ethyl-4-aminobenzoate in methanolic solution. The synthesized compound was elucidated by elemental analysis (CHN), FTIR, 1H-NMR, 13C-NMR and single crystal X-ray diffraction. E4AB crystallized in the monoclinic crystal system with space group P21/c, Z = 4, V = 1569.3(2) ?3 and unit cell parameters a = 9.1589(8) , b = 21.2003(17)?, c =8.4502(7) ?, β= 106.972(2)°. The crystal structure of the compound is stabilized by intermolecular C-H···O hydrogen bonds and weak intermolecular π···π interactions. The title compound had been tested for the antimicrobial activity against Bacillus subtilis (B. subtilis), Enterobacter and Fusarium oxysporum f. sp. Cubense (Foc) by disc-diffusion method. E4AB is relatively active against Foc which is a pathogen that cause Wilt disease (also well known as Panama disease) in banana plantation.

Synthesis, Spectral Characterization and Crystal Structure of 2-((3-Aminophenyl)(phenyl)methylene) hydrazinecarboxamide  [PDF]
Yi-Chen Chan, Abdussalam Salhin Mohamed Ali, Melati Khairuddean, Ching-Kheng Quah
Journal of Crystallization Process and Technology (JCPT) , 2013, DOI: 10.4236/jcpt.2013.32010

A benzophenone substituted semicarbazone, 2-((3-aminophenyl)(phenyl)methylene)hydrazinecarboxamide (APHC) had been synthesized in good yield by the condensation of 3-aminobenzophenone and semicarbazide hydrochloride. The title compound was elucidated by elemental analysis (CHN), FTIR, 1H and 13C-NMR, 1H-1H COSY, TGA and single crystal X-ray diffraction. The compound crystallized in the orthorhombic crystal system with space group of Pccn, Z = 32, V = 10375.1 (2) ?3, and lattice constants a = 12.3855 (1) ?, b = 34.5746 (5) ?, c = 24.2283 (3) ? and γ = β = α = 90°. The molecular view shows that APHC contains four molecules of each species in the asymmetric unit, with similar geometries. However, there is no intramolecular hydrogen bond found in the crystal structure of the synthesized compound. X-ray diffraction also reveals that the molecule of the semicarbazone exists as a Z isomer with respect to the C=N.

層面分類結構應用於圖書作品標記之研究 An Evaluation of a Faceted Structure for Book Tagging: An experimental study
Yi-Chen Chen,Muh-Chyun Tang
Journal of Educational Media & Library Sciences , 2011,
Abstract: 社會性標記的發展已成為新一代網路應用的重要趨勢之一,因其允許眾多使用者依照自身需要來為網路資源給予各種標籤或關鍵字,有別於傳統的書目組織方式。然而,現有的許多標記系統所產生的標籤大多是缺乏結構化與組織的結果,因而難以提供具語意結構的、多面向的資訊,較無法有效支援資源的瀏覽或檢索。有鑑於此,本研究提出將層面分類作為改善標記品質的方法,並且以圖書作品為例探討層面分類結構和社會性標記相結合的應用效益。研究將透過實驗法驗證層面分類結構的提供與否、以及作品文類(小說與非小說)這兩項因素對於標記結果之影響,比落漜旍晡怞b有無層面分類結構引導下進行標記所產生的結果,並透過自行設立之標記系統、實驗前問卷、與實驗後問卷分別蒐集相關實證資料,以統計檢定分析測量結果。實驗結果顯示,以層面分類進行標記較能增加標籤平均數量,且會達到較高的同義標籤相似度、標籤使用集中程度、以及較多面向之標籤類型;但也發現層面結構的提供會讓標記者花費較多操作時間,而且雖然多數標記者認同層面結構之助益,但其再利用意願並不高。研究建議提供更具彈性和多樣化的層面分類結構、增加標記系統的易用性,以減少標記操作成本;並增加標記之動機與誘因,以鼓勵使用者多花費一些心力來產出較佳的標籤品質。研究所得之成果除有助於瞭解層面分類結構與圖書標記相結合的可行性,提供後續相關研究參考外;同時也可就標記系統功能設計供相關建議,以協助使用者增進圖書標籤品質。 Recently, some have questioned the effectiveness of user-generated tags on several grounds, one of which being its lack of structure. To explore this issue, our study conducts an experiment to investigate whether user-generated tags can be enhanced with a faceted structure particularly on book tagging. This study aims to understand the effect of different tagging modes on the resulting tag sets, particularly in the context of fiction and non-fiction works. Two different kinds of tagging interfaces (with and without faceted template) and two different genres of works (fiction and non-fiction) are manipulated in this experiment. Participants’ tagging behaviors, including tags used, time spent were logged; and their perceptions with the interface was captured by the questionnaires. According to the results of assessment, it was found that the tag sets of faceted template display more distinct tags, more number of assigned tags on average, higher degree of tag similarity, and higher convergence of tags. While the results suggest that the faceted interface generated tags of better quality, it also incurred more user effort. Although it is hard to make clear conclusions based on one single study, the data suggested the usefulness of a faceted template as it tends to generate tags with higher viewpoint exhaustivity as well as consensus. Nevertheless, the actual retrieval effectiveness of the combination of tagging and faceted structure still has to be examined and assessed in further empirical research.
資料倉儲於圖書館管理應用之研究─以分析館藏圖書探討圖書採購決策 The Study of Applying Data Warehouse to Library Management-Acquisition Policy Marking Based on Collections Analysis
Jiann-Cherng Shieh,Yi-Chen Wei
Journal of Educational Media & Library Sciences , 2003,
Abstract: 近年來由於資訊爆炸與技術迅速發展,圖書館在實務運作上面臨人力資源、參考諮詢。館藏發展的種種困境。由於讀者與圖書館間密切關係的發生,多源自於流通行為,因此圖書館館藏的良窳與否,不但影響圖書館服務品質,更影響讀者對圖書館評價。而圖書採購仍是目前圖書館館藏之主要管道,因此如何訂定採購政策以確保並提昇圖書館的服務品質,被視為圖書館管理上一重要議題,於本文中我們利用資料倉儲技術,彙整圖書館自動化系統之資料庫、圖書館館際合作資料、學校系所教師專長與學生資料、選課資料等資料資源,以多維角度分析探究館藏現況與需求,以期能支援圖書館圖書採購之決策參考,進而增進圖書館服務的讀者滿意度。 Recent years, according to the challenges of inflating information rapidly and emerging technologies, libraries suffer from the issues of library collections, human resources management and the capability of consultations. The collection-related research topics are the most investigated ones. Mainly it is library circulation to cause the intimate relationships between readers and the libraries, so the quality of library collections can directly affect library services and readers evaluations. Meanwhile, book acquisitions are the major channels of collections in today s libraries. Then how to make acquisition policies to promote the quality of library services has become a critical subject in library management researches. In this paper, we apply data warehouse technology to integrate corresponding data sources about library databases, inter-library loans,courses and departments to analyze the collection situations in various views. The results are expected to support decision making in book selection thus to improve readers satisfaction in library services.
Continuous-distribution puddle model for conduction in trilayer graphene
Richard S. Thompson,Yi-Chen Chang,Jia G. Lu
Physics , 2011, DOI: 10.1140/epjb/e2011-20716-6
Abstract: An insulator-to-metal transition is observed in trilayer graphene based on the temperature dependence of the resistance under different applied gate voltages. At small gate voltages the resistance decreases with increasing temperature due to the increase in carrier concentration resulting from thermal excitation of electron-hole pairs. At large gate voltages excitation of electron-hole pairs is suppressed, and the resistance increases with increasing temperature because of the enhanced electron-phonon scattering. We find that the simple model with overlapping conduction and valence bands, each with quadratic dispersion relations, is unsatisfactory. Instead, we conclude that impurities in the substrate that create local puddles of higher electron or hole densities are responsible for the residual conductivity at low temperatures. The best fit is obtained using a continuous distribution of puddles. From the fit the average of the electron and hole effective masses can be determined.

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