Double Code Research Articles

Double codes: Community radio in Bolivia

In this article, we report results of interviews conducted with 20 informants at 8 community radio stations across the major regions of Bolivia. We explore the activism and community practices that have energized Bolivian community radio stations over a sustained period. We are in particular interested in the bottom-up networking by these community stations to interlink with each other. These networks actualize the goals of horizontal and participatory communication called for by Latin American theorists. We seek to learn from these endeavors and also contribute to their continued flourishing by analyzing potential threats to them.

Asymptotically Good Additive Cyclic Codes Exist

Long quasi-cyclic codes of any fixed index $>1$ have been shown to be asymptotically good, depending on Artin primitive root conjecture in (A. Alahmadi, C. G\"uneri, H. Shoaib, P. Sol\'e, 2017). We use this recent result to construct good long additive cyclic codes on any extension of fixed degree of the base field. Similarly self-dual double circulant codes, and self-dual four circulant codes, have been shown to be good, also depending on Artin primitive root conjecture in (A. Alahmadi, F. \"Ozdemir, P. Sol\'e, 2017) and ( M. Shi, H. Zhu, P. Sol\'e, 2017) respectively. Building on these recent results, we can show that long cyclic codes are good over $\F_q,$ for many classes of $q$'s. This is a partial solution to a fifty year old open problem.

Joint Optimization of Protograph LDPC Code Pair for Joint Source and Channel Coding

Double protograph low-density parity-check code has been shown to be a good solution for joint source-channel coding. Moreover, the source code and channel code (as one code pair) can be jointly optimized to achieve a good bit error rate (BER) performance. In this paper, first, an optimal design criterion of this code pair based on an extended curve-fitting algorithm is proposed. Second, a joint optimization procedure which searches for both the optimal decoding threshold and the optimal code pair is presented. In addition, for short-to-moderate-length codewords, the finite-length effect cannot be ignored and the procedure has to be modified with a new notion named length-N decoding threshold . The protograph extrinsic information transfer analysis and the BER simulation have shown that our optimized code pairs acquire lower decoding thresholds than conventional code pairs. Moreover, the optimized code pairs with short-to-moderate-length codewords can mitigate the finite-length effect and obtain low length-N decoding thresholds .

JEWISH MODERN LAW AND LEGALISM IN A GLOBAL AGE: THE CASE OF RABBI JOSEPH KARO

During the late sixteenth and early seventeenth centuries, Rabbi Joseph Karo composed two major Jewish codes of law: the Beit Yosef, and its abridged version, Sulchan ‘Aruch. Though several centuries of legal discussion and scholarship have passed since their publication, these double codes of law were never superseded. This codification project defined the axial place of law in Jewish tradition. I argue that it responded to changes in legal processes and the enforcement of law that simultaneously transformed early modern Europe and the Ottoman world. Transcontinentally connected changes in political institutions—the formation of a centralized Islamic empire in the Ottoman case, and the formation of centralized states in Europe—dramatically redefined the role of law and legal codification in the forging of state power and community identities. The resultant belief among Sephardi rabbis, including Karo, that changes in Jewish legal tradition were now needed, prompted a redefinition of Jewish legal culture, whereby law (a gradually centralized conception of it) began to be seen as the foundation of Jewish religious heritage and ethnic identity. Despite the absence of state backing, early modern transformations in Jewish law were thus part of comparable changes taking place in the European and Islamic legal worlds.

Design of Variable Weight code for multimedia service in SAC–OCDMA systems

Variable weight (VW) codes for spectral amplitude coding–optical code division multiple access system are useful in multimedia applications. VW code algorithm is proposed which is based on enhanced and modified double weight codes. The proposed algorithm can be used for any combination of weights >2. The cross-correlation among all users is at most 1. This code construction algorithm ensures higher power at receiver for higher-weight users. Lower-weight users receive less power compared with higher-weight users. The difference in received power translates as varying performance, and are useful for multimedia applications. The performance of VW code is analysed using balanced detection (BD) exclusive-OR operation and direct detection with exclusive-OR operation. VW code gives comparable or better performance than previously reported code. It is observed that supportable number of users for higher weight, at bit error rate (BER) of 10−9 (data) are 28, 33 and 35 for random diagonal (RD) code, Khazani-Syed (KS) code and VW code, respectively, using BD. Supportable number of users for lower weight, at BER of 10−4 (voice) are 23, 31 and 37 for RD code, KS code and VW code, respectively, using BD.

DOUBLE code simulations of emissivities of fast neutrals for different plasma observation view-lines of neutral particle analyzers on the COMPASS tokamak

Neutral particle analyzers (NPA) measure line-integrated energy spectra of fast neutral atoms escaping the tokamak plasma, which are a product of charge-exchange (CX) collisions of plasma ions with background neutrals. They can observe variations in the ion temperature Ti of non-thermal fast ions created by additional plasma heating. However, the plasma column which a fast atom has to pass through must be sufficiently short in comparison with the fast atom’s mean-free-path. Tokamak COMPASS is currently equipped with one NPA installed at a tangential mid-plane port. This orientation is optimal for observing non-thermal fast ions. However, in this configuration the signal at energies useful for Ti derivation is lost in noise due to the too long fast atoms’ trajectories. Thus, a second NPA is planned to be connected for the purpose of measuring Ti. We analyzed different possible view-lines (perpendicular mid-plane, tangential mid-plane, and top view) for the second NPA using the DOUBLE Monte-Carlo code and compared the results with the performance of the present NPA with tangential orientation. The DOUBLE code provides fast-atoms’ emissivity functions along the NPA view-line. The position of the median of these emissivity functions is related to the location from where the measured signal originates. Further, we compared the difference between the real central Ti used as a DOUBLE code input and the TiCX derived from the exponential decay of simulated energy spectra. The advantages and disadvantages of each NPA location are discussed.

Recent advances in directed evolution

Screening is the bottleneck of directed evolution. In order to address this problem, a series of novel semi-rational designed strategies have been developed based on combinatorial active-site saturation test and iterative saturation mutagenesis, including single code saturation mutagenesis, double code saturation mutagenesis and triple code saturation mutagenesis. By creation of "small and smart" high qualified mutant libraries and combinatorial mutagenesis of specific sites, these new strategies have been successfully applied in multiparameter optimization, e.g. stereo/regioselectivity and activity. This review summarized recent advances in directed evolution and its applications in biocatalysis field.

Performance analysis and optimisation for edge connection of JSCC system based on double protograph LDPC codes

For a joint source-channel coding system based on double protograph low-density parity-check codes, the exchange of extrinsic information through edge connection between the source code and channel code is essential for good performance. In this study, the relationship between the performance and edge connection in the tanner graph is analysed and it has never been seen in the literature to the authors' knowledge. Both the joint protograph extrinsic information transfer and simulation results indicate that the edge connection should be optimised in practical applications since it plays an important role in the bit error rate performance and an optimisation scheme for the edge connection is put forward to enhance performance.

Double layer 3D codes: fluorescent supramolecular polymeric gels allowing direct recognition of the chloride anion using a smart phone.

Reported here is a two-layer gel construct that permits the on-site detection of the chloride anion by means of a hand-held UV-vis lamp and a smart phone "app". To prepare this system, eight fluorescent polymeric gels G1-G8 were synthesized. Gels G1-G4 containing C4P/imidazolium-F- anion recognition motifs were used to construct a fluorescent pattern (Code A) that may be read out by a smart phone as a 3D color code (Info A). Gels G5-G8, which are based on C4P/imidazolium-Br- anion interactions, were used to construct an array (Code B) that may be read as Info B. Code B was then adhered to the surface of Code A to produce an adhered double layer code system stabilized by interfacial C4P/imidazolium-Br- anion interactions. Readout of the top layer (Code B) could be achieved without interference from Code A. Treatment with a Cl- anion source was found to delaminate the top layer and leave intact the more robust bottom layer, allowing the bottom layer (Code A) to be read out. The disparate information content associated with Codes A and B thus permits the on-site recognition of Cl-. The present sensing strategy does not rely on elaborate instrumentation and could provide a new application for elaborated soft materials.

Evaluating Direct Compare for Double Error-Correction Codes

Direct compare of information coded with error-correction codes has been proposed to efficiently protect data comparisons against soft errors. So far, it has been evaluated only for single error correction–double error detection codes. As technology scales, multiple bit errors are more frequent and, thus, more advanced protection is needed. This letter evaluates direct compare when using double error-correction codes. The results show that it can significantly reduce the circuit overheads and that the savings are larger than when used for single error correction.

On self-dual double circulant codes

Self-dual double circulant codes of odd dimension are shown to be dihedral in even characteristic and consta-dihedral in odd characteristic. Exact counting formulae are derived for them, generalizing some old results of MacWilliams on the enumeration of circulant orthogonal matrices. These formulae, in turn, are instrumental in deriving a Varshamov–Gilbert bound on the relative minimum distance of this family of codes.

D-MSSTC를 이용한 MIMO-ARQ에 관한 연구

본 논문에서는 <TEX>$4{\times}N_r$</TEX> MIMO 시스템에서 높은 스펙트럼 효율을 갖기 위해 D-MSSTC를 이용한 MIMO-ARQ 기법을 제안하였다. 제안된 기법의 오류 성능 향상을 위해, 매 전송 시 마다 MSSTC의 각 계층에 전력과 위상을 할당하였다. 추가로, 할당된 전력은 D-MSSTC의 최소 코딩 이득 거리가 최대화가 되도록 그리고 할당된 위상은 계층간의 간섭이 효율적으로 최소화 되도록 최적화를 수행하였다. 모의 실험 결과, 제안된 D-MSSTC 기반의 MIMO-ARQ 기법이 다른 기법들에 비해 우수한 성능을 얻음을 확인하였다. We proposed a multi-input multi-output automatic repeat request (MIMO-ARQ) scheme using double multi-strata space-time code (D-MSSTC) for high spectral efficiency in <TEX>$4{\times}N_r$</TEX> MIMO systems. To improve error performance of the proposed scheme, we allocate power and phase to each layer of MSSTC over every transmission. Additionally, we suboptimally optimize power allocation to maximize the minimum coding gain distance of D-MSSTC and phase allocation to efficiently minimize inter-layer interference in MSSTC. In simulation results, it is observed that the proposed MIMO-ARQ scheme based on D-MSSTC shows better block error rate (BLER) performance than conventional schemes.

D-MSSTC-SM 기법에 관한 연구

본 논문에서는 MIMO 시스템의 스펙트럼 효율 향상을 위해 두 개의 다중 시공간 블록 부호 기반의 공간변조 기법을 제안하였다. 제안된 기법의 성능 향상을 위하여, 각 MSSTC 내부의 계층에 전력과 위상을 할당하고, 공간변조 코드북에 회전각을 할당하였다. 추가로, D-MSSTC-SM 기법의 최소 코딩 이득 거리를 최대화 할 수 있도록 전력과 위상 그리고 회전각을 최적화하였다. 모의 실험 결과, 제안된 D-MSSTC-SM 기법이 높은 스펙트럼 효율을 가지면서 더 좋은 오류 성능을 얻음을 확인하였다. We proposed a spatial modulation (SM) scheme to improve spectral efficiency of multi-input multi output (MIMO) systems by using double multi-strata space-time codes (D-MSSTC). For improving the performance of proposed scheme, we allocate transmit power and phase to layers in each MSSTC, and assign rotation angle to SM codebooks. Additionally, we jointly optimize power, phase and rotation angle to maximize the minimum coding gain distance of D-MSSTC-SM. It is observed that the proposed scheme shows better error performance with high spectral efficiency than conventional schemes in simulation results.

Heterogeneous Multi-ASIP and NoC-Based Architecture for Adaptive Parallel TBICM-ID-SSD

A novel multi-ASIP and network-on-chip (NoC) based flexible architecture for parallel iterative demapping with turbo decoding using signal space diversity (TBICM-ID-SSD) is presented in this brief. The proposed heterogeneous multi-ASIP architecture uses multiple instances of two types of application-specific instruction-set processor (ASIP): one dedicated for turbo decoding and the second for demodulation, besides butterfly-topology-based NoCs. This architecture presents novel and outstanding levels of flexibility and scalability in the design of advanced iterative receivers. It supports modulation schemes from BPSK to 256-QAM for any mapping style and supports 8 state single and double binary turbo codes used in 3GPP-LTE, DVB-RCS, and WiMAX. FPGA prototyping results are presented, and the extra hardware cost required to enable turbo demodulation is evaluated.

On self-dual double negacirculant codes

Double negacirculant (DN) codes are the analogues in odd characteristic of double circulant codes. Self-dual DN codes are shown to have a transitive automorphism group. Exact counting formulae are derived for DN codes. The special class of length a power of two is studied by means of Dickson polynomials, and is shown to contain families of codes with relative distances satisfying a modified Varshamov–Gilbert bound. This gives an alternative, and effective proof of the result of Chepyzhov, that there are families of quasi-twisted codes above Varshamov–Gilbert.

Performance of ternary double circulant, double twistulant, and self-dual codes

We study the performance of ternary isodual codes which are not self-dual and ternary self-dual codes, as measured by the decoding error probability with bounded distance decoding. We compare the performance of ternary double circulant and double twistulant codes which are not self-dual with ternary extremal self-dual codes. We also investigate the performance of ternary self-dual codes having large minimum weights.

Prevalence of Personality Disorders and Clinical Syndromes Using the Millon Clinical Multiaxial Inventory III (MCMI-III) in an Iranian Clinical Sample

Personality objective inventories are commonly used for diagnosis of personality disorders. Personality assessment is effective in diagnosis, prognosis and treatment of psychiatric outpatients and in patients. Comorbid personality disorders and clinical syndromes may be more worth condition of the patients. The present study aimed to examine the diagnosis of personality disorders and clinical syndromes using the Farsi version of Millon Clinical Multiaxial Inventory III (3rd ed.; MCMI-III) in Iranian psychiatric outpatients. This was a descriptive cross-sectional study. The subjects of the project were 737 psychiatric outpatients. They were referred to the psychiatric and psychological clinics at the School of Behavioral Sciences and Mental Health-Tehran Institute of Psychiatry affiliated to Iran University of Medical Sciences, Tehran, Iran. The subjects were selected using convenience sampling during years of 2010-2015 and evaluated by the MCMI-III computerized Farsi version. Data were analyzed by descriptive methods and t test using SPSS/WIN 16.0 program. Results showed that the most frequent of personality disorders were Depressive (2B), Compulsive (7), and Histrionic (4); with double code types of Depressive- Dependent (2B3); and Histrionic- Depressive (42B) combinations. The most frequent of moderate clinical syndrome were Anxiety (A), and Dysthymia (D) and the severe syndromes was Thought Disorder (SS); with double codes of clinical syndromes of Anxiety- Post-Traumatic Stress Disorder (AR). There were significant differences between women and men patients in mean scores of some MCMI-III scales. Women had higher scores in Validity Scales of Disclosure (X) and Debasement (Z) than men. Depressive, Passive-Aggressive (Negativistic) (8A), Self-Defeating (8B) and Borderline (C) personality disorders were the most common in women than men. By contrast, Compulsive (7) personality disorder was the most common in men compare to women. Anxiety, Somatoform (H), Bipolar: Manic (N), Dysthymia (D), and Post-Traumatic Stress Disorder (R), Thought Disorder (SS), and Major Depression Disorder (CC) were the most common in women than men. The prevalence of diagnosis personality patterns and clinical syndromes in Iranian psychiatric outpatients is high and this should be taken into account in their assessment and treatment planning. Using of available sample and lack of random sample; possibility of comorbidity of other mental disorders with main diagnosis are limitations of the study. Utilization of item response theory (IRT); Structural Clinical Interviews for DSM Axis I and Axis II (SCID-I and SCID-II) along with MCMI-III; and MCMI-IV in an Iranian clinical sample are recommended.

Prevalence of Personality Disorders and Clinical Syndromes Using the Millon Clinical Multiaxial Inventory III (MCMI-III) in an Iranian Clinical Sample

Personality objective inventories are commonly used for diagnosis of personality disorders. Personality assessment is effective in diagnosis, prognosis and treatment of psychiatric outpatients and in patients. Comorbid personality disorders and clinical syndromes may be more worth condition of the patients. The present study aimed to examine the diagnosis of personality disorders and clinical syndromes using the Farsi version of Millon Clinical Multiaxial Inventory III (3rd ed.; MCMI-III) in Iranian psychiatric outpatients. This was a descriptive cross-sectional study. The subjects of the project were 737 psychiatric outpatients. They were referred to the psychiatric and psychological clinics at the School of Behavioral Sciences and Mental Health-Tehran Institute of Psychiatry affiliated to Iran University of Medical Sciences, Tehran, Iran. The subjects were selected using convenience sampling during years of 2010-2015 and evaluated by the MCMI-III computerized Farsi version. Data were analyzed by descriptive methods and t test using SPSS/WIN 16.0 program. Results showed that the most frequent of personality disorders were Depressive (2B), Compulsive (7), and Histrionic (4); with double code types of Depressive- Dependent (2B3); and Histrionic- Depressive (42B) combinations. The most frequent of moderate clinical syndrome were Anxiety (A), and Dysthymia (D) and the severe syndromes was Thought Disorder (SS); with double codes of clinical syndromes of Anxiety- Post-Traumatic Stress Disorder (AR). There were significant differences between women and men patients in mean scores of some MCMI-III scales. Women had higher scores in Validity Scales of Disclosure (X) and Debasement (Z) than men. Depressive, Passive-Aggressive (Negativistic) (8A), Self-Defeating (8B) and Borderline (C) personality disorders were the most common in women than men. By contrast, Compulsive (7) personality disorder was the most common in men compare to women. Anxiety, Somatoform (H), Bipolar: Manic (N), Dysthymia (D), and Post-Traumatic Stress Disorder (R), Thought Disorder (SS), and Major Depression Disorder (CC) were the most common in women than men. The prevalence of diagnosis personality patterns and clinical syndromes in Iranian psychiatric outpatients is high and this should be taken into account in their assessment and treatment planning. Using of available sample and lack of random sample; possibility of comorbidity of other mental disorders with main diagnosis are limitations of the study. Utilization of item response theory (IRT); Structural Clinical Interviews for DSM Axis I and Axis II (SCID-I and SCID-II) along with MCMI-III; and MCMI-IV in an Iranian clinical sample are recommended.

基于双快速反应码双随机相位加密系统的多重水印方法

基于双快速反应码双随机相位加密系统的多重水印方法

A class of skew-constacyclic codes over &amp;Zopf;&lt;SUB align="right"&gt;4 + u&amp;Zopf;&lt;SUB align="right"&gt;4

In this paper, we study a class of skew-constacyclic codes over R = Z4 + uZ4, which is a non-chain extension of Z4. Some structural properties of R[x, θ] are discussed, where θ is an automorphism of R. We determine a necessary condition and a sufficient condition for these codes to be free, when they are principally generated. A Gray map over R is defined and some good codes are obtained using it. For even n, a relation between the generator polynomial of a code and that of its dual is obtained. Some examples are given to illustrate the results. Further, we have generalised these codes to double skew-constacyclic codes over R. Some good codes with improved minimum Lee distance over Z4 have been found via this class, and the same have been added to the database of Z4 codes.