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2032. A two-stage stochastic optimization model for a gas sale retailer
- Creator:
- Maggioni, Francesca, Vespucci, Maria Teresa, Allevi, Elisabetta , Bertocchi, Marida, and Innorta, Mario
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- gas sale company, mean reverting process, and stochastic programming
- Language:
- English
- Description:
- The paper deals with a new stochastic optimization model, named OMoGaS-SV (Optimization Modelling for Gas Seller-Stochastic Version), to assist companies dealing with gas retail commercialization. Stochasticity is due to the dependence of consumptions on temperature uncertainty. Due to nonlinearities present in the objective function, the model can be classified as an NLP mixed integer model, with the profit function depending on the number of contracts with the final consumers, the typology of such consumers and the cost supported to meet the final demand. Constraints related to a maximum daily gas consumption, to yearly maximum and minimum consumption in order to avoid penalties and to consumption profiles are included. The results obtained by the stochastic version give clear indication of the amount of losses that may appear in the gas seller's budget and are compared with the results obtained by the deterministic version (see Allevi et al. \cite{ABIV}).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2033. A two-stage VoIP spam identification framework
- Creator:
- Ebrahim , Gamal A. and Younis, Akmal A:
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- VoIP, SPAM, SIP, SPIT, reputation lists, and fuzzy-logic controller
- Language:
- English
- Description:
- Identifying a VoIP call as SPAM based on call characteristics is an important issue that has never been studied before. Most of the studies of VoIP SPAM impose the whole burden on the callee to judge SPAM calls. In other words, the accuracy of the identification process is totally based on the callee identifying the call as SPAM, which is questionable and not reliable. In this paper, a two-stage VoIP SPAM identification framework is introduced. The first stage is a pre-call identification process, which uses a set of parameters about the call that can be collected before allowing the call to go through. The second stage is a post-call identification process that uses other parameters that can be collected during/after the call. The first stage provides a pre-call evaluation score of the call, while the second stage further tunes this score. In the proposed framework, the decision of identifying VoIP SPAM calls is based on several uncertain parameters that represent meta-data of VoIP calls. These parameters include call duration, amount of exchanged information in each direction, and calling pattern. In this study, the potential set of parameters that can be used to identify VoIP SPAM are investigated. A set of rules is used in addition to any prior evaluation of the caller to provide the pre-call score. Then, a fuzzy-logic controller is developed to identify VoIP SPAM in the second stage. An augmented ongoing tuning strategy is adopted where callee feedback, if any, is taken into account to further tune the identification process. Simulation studies are carried out to demonstrate the effectiveness of the two-stage approach in identifying VoIP SPAM based on the proposed framework.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2034. A two-zone model for longitudinal dispersion in channels with idealized pools nd riffles
- Creator:
- Valentine, Eric M., Zulfiqar, Ali, and Swailes, David C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dispersion, open-channel flow, dead zones, pools and riffles, numerical model, disperze, proudění v otevřených korytech, mrtvé zóny, tůně a prahy, and numerický model
- Language:
- Slovak
- Description:
- A one-dimensional two-zone mathematical model, comprising a pair of advection-dispersion equations coupled by a mass exchange term, is proposed to study longitudinal dispersion in channels with sequences of pools and riffles. An implicit finite-difference numerical scheme is employed, and its effectiveness is assessed with reference to known analytical solutions. Moreover, sets of longitudinal dispersion experiments were performed on various simple geometries of sequences of pools and riffles developed in a laboratory flume. The results were compared with corresponding numerical solutions to calibrate the two-zone model. and Pro studium podélné disperze v korytech s opakující se soustavou tůní a prahů byl navržen jednorozměrný dvouzónový matematický model. Model zahrnuje dvojici rovnic pro advektivní disperzi doplněných výrazem pro přenos hmoty. Byl použit implicitní model konečných diferencí a jeho vhodnost ověřena porovnáním se známým analytickým řešením. Navíc, v laboratorním žlabu byla provedena série měření podélné disperze pro různé jednoduché geometrie koryta se střídajícími se tůněmi a prahy. Pro kalibraci dvouzónového modelu byly výsledky měření porovnány s odpovídajícími matematickými řešeními.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2035. A ty se nermuť, že už nejsme děti, že já jsem muž a že ty jsi žena
- Creator:
- Honzák, Radkin
- Format:
- braille, electronic resource, remote, and elektronický zdroj
- Type:
- model:article, article, Text, statistics, recenze, and TEXT
- Subject:
- identifikace (psychologie), rozvoj osobnosti, pohlavní identita, kompetitivní chování, rodinné vztahy, and lidé
- Language:
- Czech
- Description:
- Honzák, R.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2036. A unified approach to several inequalities involving functions and derivatives
- Creator:
- Duoandikoetxea, Javier
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- inequalities, averages of functions, and quadrature
- Language:
- English
- Description:
- There are many inequalities measuring the deviation of the average of a function over an interval from a linear combination of values of the function and some of its derivatives. A general setting is given from which the desired inequalities are obtained using Hölder’s inequality. Moreover, sharpness of the constants is usually easy to prove by studying the equality cases of Hölder’s inequality. Comparison of averages, extension to weighted integrals and $n$-dimensional results are also given.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2037. A unique anatomical variation of the vascular supply of the ovary, uterine tube, and uterus from the greater omentum - an anatomical case study
- Creator:
- Kachlík, David, Naňka, Ondřej, Blanková, Alžběta, Turyna, Radovan, Csöbönyeiová, Mária, and Varga, Ivan
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- anatomical vascular variations, internal female genital organs, greater omentum, omental arcade of barkow, uterine artery, and ovarian artery
- Language:
- English
- Description:
- It is well known that the blood supply of the greater omentum and female internal genital organs are not physiologically connected. There is also no mention of such anatomical variation in anatomical, radiological, or surgical textbooks. Here we present a very rare case report of atypical double arterial anastomosis (the first and second variant artery) between the right limb of the omental arcade of Barkow, uterus, and right ovary, which was found during a routine student anatomical dissection course. It is very challenging to find a proper explanation for the presence of the described anatomical variation; however, we hypothesized that it is based on their common embryonic origin - the mesentery. The first and second variant arteries could be remnants of transient anastomoses or collateral circulation, which were present during embryonic development and persisted until adulthood. Moreover, during our literature review, we noticed that the general description of omental blood supply and its possible variations is relatively poor; therefore, we emphasize the need for more precise knowledge regarding these anatomical parts, which could help surgeons who are performing abdominal or pelvic surgeries in preventing avoidable bleeding.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2038. A universal method for the isolation of photochemically active broken chloroplasts from conifer needles and its possible application in photosynthetic studies
- Creator:
- Holá, D., Kočová, Marie, Rothová, Olga, Hlízová, E., Fridrichová, L., Lhotáková, Z., and Albrechtová, Jana
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, photosynthesis, photosystem I, photosystem II, 2, and 58
- Language:
- Multiple languages
- Description:
- We have developed a simple and an effective method for the isolation of photochemically active broken chloroplasts from conifer needles that can be applied for a wide variety of conifer species with needle-like leaves. The utilisation of this method in photosynthetic studies offers a possibility to examine the efficiency of almost any component of thylakoid electron-transport chain and to disclose information about individual parts of primary photosynthetic processes that would be otherwise difficult to obtain. Various aspects influencing the outcome of this procedure, including the amount of needles necessary for sufficient yields, the possible length and the conditions of their storage, the best method for their disruption, the composition and pH of isolation and storage buffers, the centrifugation sequence, etc., are discussed., D. Holá ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
2039. A uskuteční se
- Creator:
- Chaloupka, Josef
- Format:
- electronic
- Type:
- model:article and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
2040. A valid rule of β-conversion for the logic of partial functions
- Creator:
- Duží, Marie and Kosterec, Miloš
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- β-reduction by name, β-reduction by value, λ-Closure, λτ-Closure, substitution, and validity
- Language:
- Slovak
- Description:
- The goal of this paper is to examine the conditions of validity for the rule of β-conversion in TIL, which is a hyperintensional, typed λ-calculus of partial functions. The rule of β-reduction is a fundamental computational rule of the λ-calculi and functional programming languages. However, it is a well-known fact that the specification of this rule is ambiguous (see, e.g., Plotkin 1975 or Chang & Felleisen 2012). There are two procedurally non-equivalent ways of executing the rule, namely β-conversion ''by name'' and β-conversion ''by value''. In the λ-calculi conversion by name is usually applied, though it is known that such a conversion is not unconditionally valid when partial functions are involved. If a procedure that is typed to produce an argument value is improper by failing to produce one, conversion by name cannot be validly applied. On the other hand, conversion by value is valid even in the case of improperness. Moreover, we show that in a typed λ-calculus the specification of λ-closure is also not unambiguous. There is an interpretation of this specification under which β-reduction by name is not valid even when the argument procedure does not fail to produce a value. As a result, we present a universally valid rule of β-reduction by value. and Cílem této práce je zkoumat podmínky platnosti pravidla β-konverze v TIL, což je hyperintenzivní, psaný λ-kalkul dílčích funkcí. Pravidlo β-redukce je základním výpočtovým pravidlem λ-kalkulů a funkčních programovacích jazyků. Je však dobře známo, že specifikace tohoto pravidla je nejednoznačná (viz např. Plotkin 1975 nebo Chang & Felleisen 2012). Existují dva procedurálně neekvivalentní způsoby provedení pravidla, a to β-konverze '' podle názvu '' a ''β-konverze'' podle hodnoty'. V kontextu λ-kalkulů se obvykle používá konverze podle názvu, ačkoli je známo, že taková konverze není bezpodmínečně platná, pokud jde o dílčí funkce. Je-li zadaný postup, který má hodnotu parametru argumentu, nesprávný tím, že jej neproběhne, nemůže být konverzace podle názvu platně použita. Na druhé straně konverze hodnotou platí i v případě nevhodnosti. Navíc ukážeme, že v zadaném λ-kalku není specifikace uzavření λ jednoznačná. Existuje interpretace této specifikace, při níž není jméno p-redukce platné, ani když proces argumentu nedokáže vytvořit hodnotu. Výsledkem je obecně platné pravidlo β-redukce hodnotou .
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public