One of the key challenges for the IoT (Internet of Things) evolution is the network connectivity provision to a large number of resource-limited low-cost IoT devices. To meet this challenge, various efforts have been made in today's wireless network technologies, such as LTE eMTC, 5G NB-IoT, IEEE 802.11ah, BLE, etc. Meanwhile, most of these technologies consider multi-hop wireless relaying to extend the wireless coverage and to enhance the network transmission capacity. Despite the benefits, however, the usage of multi-hop relaying has been limited in the real world, because of the performance degradation caused by the self-interference between adjacent wireless links. In this paper, we tackle the problem of alleviating the performance degradation in the multi-hop wireless network for IoT devices. In particular, we target low cost IoT devices that are equipped with inexpensive wireless links such as WiFi, IEEE 802.15.4, and Bluetooth. Our approach is to avoid self-interference by controlling the transmission timing at each hop. More specifically, our design goal is to minimize the data delivery delay for fast IoT sensing by preventing packet collisions (i.e., collision-free transmission). Since the retransmission at the IoT devices is eliminated, buffering at the intermediate nodes is not necessary so that no extra storage is consumed at the IoT devices to store the data being relayed. We present an algorithm to produce the packet transmission schedule at each hop. We prove that our algorithm is optimal in terms of data delivery delay (i.e., minimal delay is guaranteed) while collision between transmissions is completely avoided.

A discrete problem can be relaxed by taking the continuous relaxation of an integer programming formulation An equivalent relaxation is obtained by projecting this relax ation onto the original continuous variables The projection is simple for piecewise linear functions xed charge problems and some disjunctive constraints This allows one to solve much smaller relaxations without sacri cing the quality of bounds In particular the projected relaxations for some classical network design and warehouse location problems are minimum cost network ow problems a fact that can dramatically accelerate their solution A relaxation for a problem with discrete elements is often obtained by adding integer variables to the model The integrality constraints not only capture the discrete element but can be dropped in order to obtain a continuous relaxation of the model An equivalent relaxation can be obtained however by projecting the traditional continuous relaxation onto the original continuous variables Projection can generate a large number of inequality constraints but in some important special cases it does not In such cases one can obtain a relaxation that is of the same quality as the conventional one but much more succinct due to the absence of integer variables Occasionally the projected relaxation has special structure that the convention relaxation lacks and can be more easily solved for that reason as well Once integer variables are removed from the relaxation they can be eliminated entirely Logical expressions can be used to express the discrete elements of a problem perhaps more naturally as noted in Branching on logical possibilities or propositional variables can re place branching on integer variables This may even allow branching to terminate sooner than in an integer programming context as argued in In any case the use of projected relax ations almost certainly accelerates the solution of the problem because it provides the same bounds as traditional integer programming and does so more rapidly because the relaxations are smaller This paper examines three projected relaxations First Beaumont s use of elementary inequalities to relax logical disjunctions is brie y reviewed and strengthened due to the usefulness of disjunctions for expressing the discrete aspect of a problem Next a simple convex hull relaxation of piecewise linear functions is presented Finally it is noted that xed charge problems also have a compact projected relaxation In particular the projected relaxation of xed charge network ow problems including warehouse location problems has the structure of a minimum cost network ow problem whereas the conventional relaxation does not This permits a far more rapid solution of the relaxation than is otherwise possible Because solving the relaxation consumes nearly all the solution time in branch and bound algorithms projected relaxations can dramatically accelerate the solution of these problems The relaxations presented here are simple Nonetheless they and their advantages are normally overlooked Elementary Inequalities Beaumont showed that a single elementary inequality relaxes a disjunction of linear inequal ities

Generally, the lifetime of a wireless sensor network (WSN) is defined as the duration until any sensor node dies due to battery exhaustion. If the traffic load is not properly balanced, the batteries of some sensor nodes may be depleted quickly, and the lifetime of the WSN will be shortened. While many energy-efficient routing schemes have been proposed for WSNs, they focus on maximizing the WSN lifetime. In this paper, we propose a scheme that satisfies a given ‘target’ lifetime. Because energy consumption depends on traffic volume, the target lifetime cannot be guaranteed through energy-efficient routing alone. We take an approach that jointly optimizes the sensing rate (i.e., controlling the sensor-traffic generation or duty cycle) and route selection. Satisfying the target lifetime while maximizing the sensing rate is a NP-hard problem. Our scheme is based on a simple Linear Programming (LP) model and clever heuristics are applied to compute a near-optimal result from the LP solution. We prove that the proposed scheme guarantees a 1/2-approximation to the optimal solution in the worst case. The simulation results indicate that the proposed scheme achieves near-optimality in various network configurations.

It is unavoidable to provide products that meet customers' needs and wants so that firms may survive under the competition in this globalized market. This paper focuses on how to provide levels for attributes that compse product so that firms may give the best products to customers. In particular, its main issue is how to determine common attributes and the others with their appropriate levels to maximize firms' profits, and how to construct a decision support system to ease decision makers' decisons about optimal common attribute selection using the Semantic Web and SWCL technologies. Parameter data in problems and the relationships in the data are expressed in an ontology data model and a set of constraints by using the Semantic Web and SWCL technologies. They generate a quantitative decision making model through the automatic process in the proposed system, which is fed into the solver using the Logic-based Benders Decomposition method to obtain an optimal solution. The system finally provides the generated solution to the decision makers. This presentation suggests the opportunity of the integration of the proposed system with the broader structured data network and other decision making tools because of the easy data shareness, the standardized data structure and the ease of machine processing in the Semantic Web technology.

A novel X-type polyester (5) containing 4-(2,2-dicyanovinyl)-6-nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone, was prepared and characterized. Polyester 5 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. Polyester 5 shows thermal stability up to 300 degrees C from thermogravimetric analysis with a glass transition temperature obtained from differential scanning calorimetry of near 108 degrees C. The second harmonic generation (SHG) coefficient (d(33)) of poled polymer films at the 1064 nm fundamental wavelength is 2.99 pmV(-1). The dipole alignment exhibits thermal stability even at 7 degrees C above the glass transition temperature, and no significant SHG decay is observed below 115 degrees C due to the partial main-chain character of the polymer structure, which is acceptable for NLO device applications. (c) 2013 Society of Chemical Industry

Novel X-type polyurethane 4 containing 4-(4-nitrophenylazo)-6-nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which are parts of the polymer main chains, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It shows thermal stabilities up to 270 degrees C from thermogravimetric analysis with glass transition temperature obtained from differential scanning calorimetry of about 134 degrees C. The second harmonic generation (SHG) coefficient (d(33)) of poled polymer film at 1064 nm fundamental wavelength is 5.37 x 10(-9) esu. Polymer 4 exhibits a thermal stability up to T-g, and no significant SHG decay is observed below 135 degrees C, which is acceptable for NLO device applications. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 760-766

A new Y-type polyester (3) containing nitrophenylazocatecholic groups as NLO chromophores, which are parts of the polymer backbone was prepared. Polyester 3 is soluble in common organic solvents such as acetone and dimethylsulfoxide. It shows a thermal stability up to 280 degrees C from thermogravimetric analysis with glass-transition temperature (T-g ) obtained from differential scanning calorimetry near 86 degrees C. The second harmonic generation (SHG) coefficient (d(33) ) of poled polymer film at the 1064nm fundamental wavelength is around 4.42 x 10(-9) esu. The dipole alignment exhibits a thermal stability even at 4 degrees C higher than T-g , and no SHG decay was observed below 90 degrees C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Novel X-type polyester containing 4-(2,2-dicyanovinyl)-6-nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone, was prepared and characterized. Polyester is soluble in common organic solvents such as N,N-dimethylformamide and acetone. Polyester shows a thermal stability up to 300 degrees C from thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry of near 108 degrees C. The second harmonic generation (SHG) coefficient (d(33)) of poled polyester film at the 1064nm fundamental wavelength is 7.13 x 10(-9) esu. The dipole alignment exhibits a thermal stability even at 7 degrees C higher than glass-transition temperature (T-g), and no significant SHG decay is observed below 115 degrees C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

Early-onset Pericardial Effusion after Autologous Hematopoietic Stem Cell Transplantation in a Child with Neuroblastoma Jong Hyung Yoon, M.D., Hak Jin Kim, M.D., Su Jin Kim, M.D., Yong Soo Yun, M.D., Jong In Chun, R.N., Hyeon Jin Park, M.D. and Byung-Kiu Park, M.D. Center for Pediatric Oncology, Center for Clinical Specialty, Cardiology Clinic, National Cancer Center, Department of Pediatrics, Myongji Hospital, Goyang, Korea

Novel X-type polyurethane 5 containing 4-(2',2'-dicyanovinyl)-6-nitroresorcinoxy groups as nonlinear optical (NLO) chromophores, which constitute parts of the polymer backbone, was prepared and characterized. Polyurethane 5 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It shows thermal stability up to 280 degrees C from thermogravimetric analysis with a glass transition temperature (Tg) obtained from differential scanning calorimetry thermogram of around 120 degrees C. The second harmonic generation (SHG) coefficient (d33) of poled polymer film at 1064-nm fundamental wavelength is around 6.12 x 10-9 esu. The dipole alignment exhibits a thermal stability even at 5 degrees C higher than Tg, and there was no SHG decay below 125 degrees C due to the partial main chain character of the polymer structure, which is acceptable for NLO device applications. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Intrusion Detection Systems (lDSs), nowadays, critically becomes an important security component in the novel commercial computing models to detect malicious behaviors timely and protect either network infrastructure or individual hosts from the serious damage of attacks. For Cloud Computing, various application scenarios and complexity at a higher level make the traditional IDS approaches difficult to find out the actual threats from the novel multi-step attacks, which stem from the new vulnerabilities of Cloud environments. Therefore, information about novel attack scenarios is an urgent requirement to operate IDSs built in Cloud Computing more efficiently and accurately. This paper focuses on developing a data mining-based approach to construct new attack scenarios from the sequences of low-level alerts gathered from multiple traditional IDSs. In addition, an Attack Signature Exchange (ASE) model between Interconnect Clouds in a Collaborative Cloud Computing environment which is considered as a prior knowledge exchange is also presented. Key-words: Intrusion Detection System, Cloud Computing, Attack scenario, Attack Signature, Collaborative Cloud

Utility computing services constitute business opportunities in the customer-to-customer (C2C) marketplace. Providers deal with the risks and uncertainties faced by users while transacting with unfamiliar counterparts. Ensuring trustworthy transactions among unfamiliar users is an important condition of utility-computing service. Many peer-to-peer (P2P) sites utilize reputation systems; however, such systems are subject to lack of reviewer objectivity and robustness against attacks as well as unfair ratings. In this study, we propose the manual adjustment of reputation ratings by means of transaction monitoring and establish that the resulting enhanced objectivity and robustness in utility-computing service transactions will strengthen the trust management system. We also propose the optimal level of monitoring and penalizing activities based on the level of privacy concerns among users and the appropriate complementary service.