Earticle

듀플렉스 스테인리스강은 일반 오스테나이트계 스테인리스강과는 다른 열적, 기계적 성질로 인하여 일반 스테인리스강과는 다른 잔류응력 크기와 분포를 가진다. 따라서 듀플렉스 스테인리스강을 강구조물에 적용시키기 위해서는 용접부의 잔류응력 특성에 대한 연구가 반드시 선행되어야 한다. 본 연구에서는 듀플렉스 스테인리스강 용접시 발생하는 잔류응력을 스트레인 게이지를 이용한 응력 이완법을 이용하여 실험적으로 측정하여 용접부의 잔류응력 특징을 조사하였다.

Duplex stainless steel finds increasing use as an alternative to austenitic stainless steel, particularly where chloride or sulphide stress corrosion cracking is of primary concern, due to the excellent combination of strength and corrosion resistance. During welding, duplex stainless steel does not create the same magnitude or distribution of weld-induced residual stresses as those in welded austenitic stainless steel due to the different physical and mechanical properties between them. In this work, an experimental study on the residual stresses in butt-welded duplex stainless steel is performed utilizing the layering technique to investigate the characteristics of residual stresses in the weldment.

In recent years, there has been a considerable interest in the application of super plastic forming in the aircraft and automotive industries. This requires a detailed design of the technological process in order to exploit its peculiar potentialities better. Nowadays, the finite element method is used to plan the sheet metal forming processes whose simulation requires determination of material constants for super plastic materials. The present work is aimed to show a simple method to characterize super plastic materials duplex stainless steel which was formed by a constant gaspressure to hemispheres with and without back pressure. The forming operation was performed using an in-house designed and built biaxial forming apparatus. The temporal change of dome heights of hemispheres were measured for applying the pressures. The flow stresses and strain rates developed at the top of the dome during the forming step were shown to follow closely the flow stress - strain rate relationship obtained from the strain rate change tests performed at the same temperature.

두 가지 primer 쌍을 동시에 이용한 duplex PCR 기법으로 붉은사슴과 엘크의 유전자 성 판별에 대한 이용가능성을 확인하기 위해 본 연구를 수행하였다. 근본적으로 포유동물의 성 분화는 Y-염색체 상에 암호화되어 있으며 웅성발생에 지배적인 역할을 수행하는 SRY 유전자의 존재 여부에 따라 결정되게 된다. X-, Y- 염색체에 상동인 유전자들 중 하나인 ZFX-ZFY 유전자는 X-, Y- 염색체 상에서 각각 발견된다. 유전자 성 판별에 앞서 붉은사슴의 ZFX-ZFY 유전자의 인트론 9를 포함하는 절편에 대한 염기서열의 특성을 확인하였다. 인트론 9의 길이는 ZFX와 ZFY에서 각각 529, 665-bp로 확인되었다. ZFY 인트론 9에서 전위인자의 일종인 bovine SINE element와 유사한 서열이 관찰되었다. SRY와 ZFX-ZFY 유전자들을 동시에 증폭하는 duplex PCR을 통해 유전자 성 판별을 수행하였고, 암수가 서로 구분되는 증폭 양상을 나타내었다: 암컷에서는 ZFX에서 증폭된 공통의 증폭 산물 하나만이 관찰되었고 수컷은 세 개의 밴드가 관찰되었다(ZFX에 해당하는 공통의 밴드와 ZFY와 SRY에서 증폭된 두 개의 수컷 특이 밴드). 두 가지 유전자에 대한 독립적인 PCR 시험에서 얻은 결과는 duplex PCR에 의해 얻은 결과와 동일한 양상을 나타내었다. 또한 유전자 성 판별의 결과들은 각각의 개체에 대한 표현형적 성판별 자료와 정확히 일치하였다. Y 염색체 특이적인 SRY와 X-, Y- 상동이면서 성적 이형성을 나타내는 ZFX-ZFY 유전자들에 대한 duplex PCR 방법은 붉은사슴과 엘크의 성 판별에 있어 여타 다른 대조시험을 요구하지 않으면서 없이 신속하고 정확한 정보를 제공하는 분석법이 될 것으로 기대된다.

This study was focused on discriminating the molecular sexes of red deer and elk by duplex polymerase chain reaction(PCR) using two primer sets. Sex differentiation of mammals is primarily dependent on the presence or absence of sex determining region Y(SRY) gene encoded on Y chromosome which plays a key role for male development. Zinc finger X-Y(ZFX-ZFY) gene, one of X-Y homology gene group was found on X- and Y- chromosomes, respectively. At first, the nucleotide sequences were characterized for the intron 9 flanking region of ZFX-ZFY genes. The intron 9 of ZFX and ZFY is 529-bp and 665-bp in length, respectively. A transposable element sequence similar to bovine SINE element Bov-tA was detected only in ZFY gene of Cervidae. Sexing analysis was conducted by duplex PCR assay for amplification of SRY and ZFX-ZFY genes. Two differentially amplified patterns were found: one for females has a common band amplified only from ZFX as a template, and another for males had three bands(a common ZFX and two male-specific ZFY and SRY). On the separate tests using each gene, the results was identical to those from duplex PCR assay. Moreover, the results from PCR assays provide also identical information to phenotypic investigation of individuals of red deer, elk as well as their hybridized progenies collected from two isolated farms. These results suggest that it may be a rapid and precise method for determining the sexes by duplex PCR amplification using Y-chromosome specific SRY and X- and Y- homologous ZFX-ZFY genes showing sexual dimorphism in red deer and elk without any other controls.

Background: In this study, a duplex probe-based reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay was used to simultaneously detect Cycas necrotic stunt virus (CNSV) and Lychnis mottle virus (LycMoV) in Paeonia lactiflora (peony) collected from various locations in South Korea. Methods and Results: CNSV and LycMoV infections were verified by using conventional RT- PCR using gene-specific primers. A high-precision quantification duplex probe-based qPCR assay was conducted on plasmid DNAs of target viruses and optimized to select the best-performing primers characterized by their ability to yield high relative fluorescence units and low cycle thresh- old values. Stable and consistent amplification plots and standard curves were achieved with primer and probe concentration of 0.25 µM and 0.2 µM, respectively, and an annealing tempera- ture of 57℃. RT-qPCR was used with the selected primer sets and optimum conditions to detect the total RNA of peony leaves co-infected with CNSV and LycMoV. Successful detection occurred with a slightly weak sensitivity, having a detection limit of 10-3 ng/㎕. Conclusions: The duplex probe-based RT-qPCR assay demonstrated in this study can improve the screening process for CNSV and LycMoV, leading to a reduction in the spread of these two plant viruses.

A novel duplex scheme, region-based division duplex (RDD), is proposed to address the cross-tier interference issue in heterogeneous networks. The proposed RDD leverages the location of the user to select the link direction of a small cell between the forward and reverse duplex modes. Moreover, a coordinated scheduling algorithm is developed where pairing between macro and small cells and the duplex mode of each small cell is jointly decided. Simulation results show that the proposed RDD achieves an approximately 40% gain in network sum capacity compared with conventional TDD-based duplex schemes.

In this letter, non-regenerative Amplify-and-Forward (AF) relay systems based on half and full duplex schemes are investigated and their performance is analyzed and compared in terms of outage probability. Although the AF relay systems have been widely investigated in many previous literatures, most of them adopted a half duplex scheme due to hardware limitation and mathematical tractability. To the best of our knowledge, this letter is the first study to investigate the performance of the full duplex AF relay system considering practical hardware limitations. In full duplex AF relay systems, it is important to secure the isolation between transmit and receive antennas. Our numerical and simulation results show that there exists a threshold point of the isolation gain that the full duplex relay system outperforms the half duplex relay system.

Unmanned aerial vehicle (UAV) relaying network systems have been widely studied to expand network coverage and improve frequency efficiency for wireless communication. This paper proposes a carrier sense multiple access with collision avoidance (CSMA/CA) based group contention (GC) full-duplex (FD) UAV relay system. The proposed FD UAV relay system guarantees the establishment of an FD pair. The UAV acts as a relay node and notifies the next-hop destination to all nodes with the acknowledge (ACK) packet. Only nodes that can establish the FD pair with the next-hop destination compete for channel access. No matter which node wins the channel contention, throughput and delay are improved because it can guarantee the FD pair establishment. Both analytical and simulation results verified that the proposed FD UAV relay system could achieve better throughput and delay than a conventional UAV relay system.

A duplex system enhances reliability by tolerating faults through spatial redundancy. Faults can be detected by duplicating identical tasks in pairs of modules. However, this kind of systems cannot even detect the fault if it occurs coincidently due to either malfunctions of common component such as power supply and clock or due to such environmental disruption as EMI. In the paper, we propose a method to reduce those effects of coincident faults in the duplex controller computer. Specifically, a duplex system tolerates coincident faults by using a sophistication sequencing of scheduling technique with certain timing redundancy. In particular when all tasks should be completed in the sense of real-time, the suggested scheduling method works properly to minimize the probability of faulty tasks due to coincident fault without missing the timing constraints.

This paper proposes a routing scheme for full-duplex-(FD)-based multi-hop CRNs that attempts to maximize the packet-delivery-ratio between any source?destination pair by being aware of the time-varying nature of spectrum-availability of the operating environment. The proposed routing scheme consists of path selection and channel assignment. Two design variants are presented: one for inband- and the other for outband-FD CRNs. Our scheme is performed into three phases: path-discovery (to identify a set of feasible routes), channel-selection (to assign channels along each path) and path-selection (to select the highest effective availability-time path). Compared to a reference scheme, the simulation results indicate that being spectrum-availability-aware can achieve significant performance enhancement.

We consider a decode-and-forward full-duplex relaying system for multiple pairs of users. Our objective is to maximize the minimum achievable rate for all user pairs under the transmit power constraints.We propose an iterative algorithm to solve the nonconvex max?min problem. In particular, the original problem is converted into successive convex programs by using an inner approximation method such that each iteration involves only a simple convex quadratic program. We show that the proposed algorithm improves achievement of the objective iteratively while guaranteeing convergence. Simulation results demonstrate that the proposed algorithm provides higher rates than both half-duplex and full-duplex relaying based on zero-forcing do.

In this paper, we consider an unmanned aerial vehicle (UAV)-assisted downlink cellular network consisting of a single base station (BS), two mobile stations (MSs) with antennas, and UAV relay stations (RSs). We assume that there exists no direct link between the BS and the MSs due to unexpected blockages such as obstacles and disasters. We propose a UAV-assisted cooperative downlink non-orthogonal multiple access (NOMA) with virtual full-duplex (VFD) operation for improving spectral efficiency in such an environment. In the proposed VFD technique, a single UAV-RS is selected among multiple UAV-RS. Through computer simulations, we verify that the proposed cooperative NOMA technique with VFD operation significantly outperforms the conventional cooperative NOMA technique with half-duplex operation in terms of outage probability.

This paper considers a broadband multicell system with key characteristics that base-stations and relays employ beamforming via large antenna arrays, as well as in-band full duplex relay operation. The signal to interference plus noise ratio gain (which is in excess of the maximum required for such a system) could be exploited either for reducing self-interference or the backhaul and access link transmitted powers. The presented results indicate that with a moderate front-to-back-ratio scenario for the antenna array, “small” antenna arrays with 8 elements can lower the requirement of full duplex self-interference cancellation by up to 55 dB, while large antenna arrays of 1024 elements will produce 100 dB reduction. Alternatively, for the same scenario, both the backhaul and access transmitted powers could be reduced by ∼55 dB and ∼25 dB with 1024 elements.

The microstructure and mechanical properties of the heat-affected zone welded using the GTAW process on SDSS material used in offshore structures were analyzed. The chemical composition of the specimen material was analyzed using XRF. The microstructure of the heat-affected zone where the plate was welded was examined by SEM, and the ferrite volume fraction was assessed using the point count method of ASTM E562. A lot of ferrite was formed in the overheated weldment region, and In the weld cap where the cooling rate was fast, ferrite was not converted back to austenite and the microstructure was not uniform. From the ferrite phase fraction, it was shown that it can be applied to the pitting resistance equivalent numbers through changes in mechanical properties according to welding conditions.

차세대 5G 및 6G 네트워크는 고대역폭, 초저지연, 그리고 유연한 트래픽 관리를 요구하며, 이는 기존 하향 중심(DL-dominant) 서비스에서 상향 중심(UL-heavy) 또는 균형 잡힌 트래픽 구조로의 전환을 지원하기 위함이다. 기존 4G 시분할 이중화(TDD)는 고정된 상향/하향(Uplink/Downlink, UL/DL) 구성 방식을 사용한 반면, 5G New Radio(5G NR)는 정의된 절차 내에서 동적 구성 변경이 가능하여 최적의 슬롯 패턴 설계가 가능하다. 본 논문에서는 5G NR 네트워크에서 시분할 이중화 패턴 선택을 최적화하기 위해 딥 Q-러닝(Deep Q-Learning, DQL) 기반 아키텍처를 제안한다. 이 아키텍처는 사용자 단말(UE) 밀도, 간섭 수준, 상향 및 하향 트래픽 부하 등 핵심 네트워크 특성을 모델링하도록 설계하였다. 시분할 방식에 기반한 5G 네트워크에서 동적 트래픽 요구를 충족하면서도 낮은 지연 시간과 높은 처리율을 유지하기 위해서는 UL/DL 슬롯 구성을 최적화하는 것이 중요하다. 또한, 본 논문에서는 실시간 트래픽 패턴에 대응하여 UL/DL 구성을 학습하고 조정할 수 있는 DQL 기반 방법을 제안하였다. 제안된 DQL 에이전트는 5G 시뮬레이션 환경에서 지연 시간 감소와 처리율 향상을 동시에 고려한 보상 함수를 최적화하도록 학습되었다. 성능 평가는 고정된 4:4 UL/DL 구성과 비교하여 진행되었으며, 실험 결과 제안된 DQL 기반 방식은 기존 방식 대비 처리율 측면에서 95% 이상, 지연 시간 측면에서 50% 이상의 향상을 보였다. 이러한 결과는 제안된 DQL 기반 접근법이 미래 시분할 이중화 시스템에서 지능적이고 유연한 슬롯 스케줄링을 실현할 수 있는 높은 가능성을 입증한다.

Emerging 5G and 6G networks demand high bandwidth, ultra-low latency, and adaptable traffic management to facilitate services which are transitioning to balanced uplink traffic from heavily downlink-dependent traffic. In contrast to 4G Time Division Duplex (TDD), which uses static Uplink/Downlink (UL/DL) configurations, 5GNR enables dynamic modification of defined procedures for the best possible pattern design. In order to optimize TDD pattern selection in 5G New Radio (NR) networks, this paper suggests a Deep Q Learning (DQL) architecture. It was created to model important network characteristics, including as user equipment (UE) density, interference, and uplink and downlink traffic loads. Optimizing uplink (UL) and downlink (DL) slot designs is essential for 5G networks based on TDD in order to satisfy dynamic traffic needs while preserving low latency and high throughput. A DQL method that learns to modify UL-DL configurations in response to real-time traffic patterns is presented in this study. The DQL agent is trained in a simulated 5G environment to maximize a reward function that combines latency reduction and throughput gain. The DQL-based approach's performance is evaluated in comparison to a static 4:4 UL-DL configuration baseline. The suggested paradigm dramatically increases network performance and lowers latency, according to experimental data. In particular, the DQL agent outperforms the baseline by more than 95% in throughput and 50% in latency, demonstrating its promise for intelligent and flexible slot scheduling in TDD systems of the future.

본고는 철학과 미학에서 唯物主義와 唯心主義로 二分化되는 체계를 謝赫 氣韻론의 氣와 연관하여 기론의 이중적 체계와 그 실태를 고찰한다. 氣論을 객관적ㆍ주관적 ‘氣’, 또는 물질적ㆍ정신적 ‘氣’, 즉 唯物主義와 唯心主義의 분해적 관념에서 역대 기론을 중심으로 고찰하여 그 심미적 사유체계를 분석한 결과 유물주의적 ‘氣’와 유심주의적 ‘氣’는 양방의 내적 연관성 없이 한 방면으로서는 예술의 심미적 목표에 도달할 수 없다는 결론에 이른다. 그러한 문제의 사유는 결국 인간의 심미적 의식체계가 자연 중심이냐 인간 중심이냐의 문제로서 예술과 미학은 유물주의ㆍ유심주의의 정신적 해방에서 우주만물의 생명리듬을 和諧的으로 표현하는 총체적 관념의 氣論이 되어야 함을 밝히고 있다. 우주자연의 법칙이 인간의 지적활동인 道ㆍ心ㆍ性ㆍ情ㆍ神ㆍ意ㆍ氣ㆍ理ㆍ德 등 예술성의 ‘氣’로 발전하는 미학범주와 만나서 또 다른 형식을 무한으로 창조해낼 수 있는 열쇠는 화해해야만 실제로 만물을 生하는 것이며, 그것이 기운을 내재하는 공정이 되는 것이다. 하나의 작품은 物ㆍ我, 主ㆍ客, 心ㆍ景, 心ㆍ物, 情ㆍ景, 意ㆍ境의 통일을 이룬 和諧만이 예술이 예술 될 수 있게 하고, 예술가가 추구해야할 높은 수준의 境界에 도달할 수 있다. 따라서 예술과 미학상의 ‘氣’는 분해적 관념의 氣論이 아니라, 唯物ㆍ唯心이 상호 결합되는 총체적 관념의 和諧論적 氣論이 되어야 사혁의 氣韻生動論에 부합될 수 있으며, 인간과 자연의 조화를 체득하여 자연과 인간이 합일되는 최고의 경계인 天人合一로 나아갈 수 있다.

This study investigated the duplex system and the actual condition of the theory of energy relating the system which is classified into materialism and spiritualism in philosophy and aesthetics to the energy in Xiehe’s theory of atmosphere. It also categorized the theory of energy into objective energy and subjective energy or material energy and spiritual energy. In the concepts of understanding materialism and spiritualism separately, it analyzed the aesthetic thinking system. As a result, it arrived at a conclusion that either material energy or spiritual energy cannot reach the aesthetic objective of art. In addition, it determined that art and aesthetics concerned about which human’s aesthetic conscious system is based on between nature and human should spiritually deviate from the concern about choosing materialism or spiritualism, and art and aesthetics should be the theory of energy as an overall concept that harmoniously expresses vital rhythm of universe. The harmony, which achieved the union of things and myself, subjective and objective, mind and scenery, mind and things, scenery and emotion, and will and boundary, can make an artwork art itself, and it can make an artist reach the high boundary that an artist should pursue. Therefore, the energy in art and aesthetic should be understood not through the theory of energy that understands the concept of energy separately but through the theory of a harmonious energy as an overall concept. Then, it can be satisfied with Xiehe’s theory that atmosphere is full of vitality, and an artist can reach the highest boundary that heaven and human unite by acquiring the harmony of human and nature.

The wireless mesh network (WMN) is a next-generation technology for data networking that has the advantage in cost and the flexibility in its construction because of not requiring the infra-structure such as the ethernet. This paper focuses on the optimal link scheduling problem under the wireless mesh network to effectuate real-time streaming by using the constraint programming. In particular, Under the limitation of half-duplex transmission in wireless nodes, this paper proposes a solution method to minimize the makespan in scheduling packet transmission from wireless nodes to the gateway in a WMN with no packet transmission conflicts due to the half-duplex transmission. It discusses the conflicts in packet transmission and deduces the condition of feasible schedules, which defines the model for the constraint programming. Finally it comparatively shows and discusses the results using two constraint programming solvers, Gecode and the IBM ILOG CP solver.

본 연구는 소직경 원통형 포장용기에 적용되는 단면 이중지 라벨에서 발생하는 가장 자리 분리 및 들뜸(edge lift) 문제를 개선하기 위해 접착 면적 비율과 구조적 설계 요소가 접착 안정성과 사용성에 미치는 영향을 실험적으로 분석하였다. 백색 폴리에틸렌(PE) 85㎛와 백색 폴리프로필렌(PP) 80㎛ 피인쇄체을 적용한 단면 이중지 라벨 샘플을 제작하였고, 실리콘 무접부와 접착부를 사선 구조로 구성하여 접착 면적 비율을 약 27%에서 55%까지 단계적으로 변화시켰다. 제작된 샘플을 소직경 원통 형 용기에 부착한 후, 상온 및 50℃ 고온 조건에서 외관 중심의 평가를 수행하였다. 실험 결과, 접착 면적 비율이 27%인 PP 80㎛ 샘플에서만 부착 후 24시간 경과 시 미세한 들뜸 현상이 관찰되었으며, 접착 면적 비율이 33% 이상인 모든 조건에서는 분 리 또는 들뜸 현상이 발생하지 않았다. 또한 접착 면적 비율이 33% 이상인 조건에서는 분리 후 재부착이 가능하고 외관 안 정성이 유지되었다. 라벨 분리 방향과 동일한 각도의 사선 구조는 분리 시 박리력 집중 을 완화하여 가장자리 들뜸의 진행을 억제하는 데 기여한 것으로 판단된다. 본 연구는 소직경 포장용기용 단면 이중지 라벨 설계 시 접착 면적 비율과 구조적 설계의 중요성을 실험적으로 제시하였다.

This study experimentally analyzed the effects of the adhesive area ratio and structural design factors on adhesion stability and usability in order to improve edge separation and edge lift issues occurring in duplex labels applied to small-diameter cylindrical containers. Duplex label samples were fabricated using white polyethylene (PE) substrates with a thickness of 85 μm and white polypropylene (PP) substrates with a thickness of 80 μm. The silicone non-adhesive region and adhesive region were configured in a diagonal structure, and the adhesive area ratio was varied stepwise from approximately 27% to 55%. The fabricated samples were applied to small-diameter cylindrical containers, and visual-based evaluations were conducted under ambient conditions and at an elevated temperature of 50 °C. As a result, minor edge lift was observed only in the PP 80 μm sample with an adhesive area ratio of 27% after 24 h of application, whereas no separation or edge lift occurred in all conditions with adhesive area ratios of 33% or higher. In addition, under conditions with adhesive area ratios of 33% or higher, the labels could be reattached after separation while maintaining stable external appearance. The diagonal structure, aligned with the label separation direction, was found to contribute to suppressing the progression of edge lift by alleviating the concentration of peel forces during separation. This study experimentally demonstrates the importance of the adhesive area ratio and structural design in the development of duplex labels for small-diameter cylindrical containers.