Scope Of Operations Research Articles

Simulation-Based Assessment of the Effectiveness of Tests for Stationarity

Non-stationarity potentially comes from many sources and they impact the analysis of a wide range of systems in various fields. There is a large set of statistical tests for checking specific departures from stationarity. This study uses Monte Carlo simulations over artificially generated time series data to assess the effectiveness of 16 statistical tests to detect the real state of a wide variety of time series (i.e., stationary or non-stationary) and to identify their source of non-stationarity, if applicable. Our results show that these tests have a low statistical power outside their scope of operation. Our results also corroborate with previous studies showing that there are effective individual statistical tests to detect stationary time series, but no effective individual tests for detecting non-stationary time series. For example, Dickey-Fuller (DF) family tests are effective in detecting stationary time series or non-stationarity time series with positive unit root, but fail to detect negative unit root as well as trend and break in the mean, variance, and autocorrelation. Stationarity and change point detection tests usually misclassify stationary time series as non-stationary. The Breusch-Pagan BG serial correlation test, the ARCH homoscedasticity test, and the structural change SC tests can help to identify the source of non-stationarity to some extent. This outcome reinforces the current practice of running several tests to determine the real state of a time series, thus highlighting the importance of the selection of complementary statistical tests to correctly identifying the source of non-stationarity.

Market Electrification for BEV and PHEV in Relation to the Level of Vehicle Autonomy

The automotive market has been developing very dynamically recently. Contemporary trends focus on the development of the so-called intelligent vehicles, often combined with modern technology and supporting systems. Cars with a large scope of operation in terms of driving autonomy can increasingly be found. These types of solutions can lead to changes in production processes through the emergence and growing importance of new concepts and technologies. The article presents the concept of BEV (Battery Electric Vehicle) and PHEV (Plug-in Hybrid Electric Vehicle) vehicles in relation to modern solutions and their levels of autonomy. The research was conducted in various groups of respondents, while the analyses were carried out mainly with the use of two grouping variables: gender and place of residence. Based on our own research, it can be concluded that due to many different factors, most respondents believe that PHEV hybrid vehicles and electric vehicles (BEV) are currently, and will most likely be in the near future, the dominant type of vehicles appearing on roads in Poland, at the same time indicating the level of advancement of autonomy as average (mainly level 1, 2 and 3).

The Current State of Transnational Organized Crime

The paper indicates that criminal groups may differ in terms of size, the scope of operations, types of activities, territorial range, relations with authorities and management, internal organization, and the set of means and methods used to promote their criminal activities and to guard against measures taken by the Government and law enforcement bodies. When national, historical, and cultural differences are taken into account, the diversity of criminal organizations becomes even more evident, while prevention and suppression pose even greater challenges for law enforcement agencies, especially in countries where these organizations are active in their illegal activities. The study is aimed at analyzing national-level legislative measures that may be efficient about one type of organized criminal group, but may not be appropriate for other types. To solve the problems formulated, a complex methodology will be required, combining empirical studies of specific facts and a fundamental theoretical understanding of the conceptual foundations of the problem posed. The results of the analysis made it possible to theoretically substantiate the increased social danger of transnational organized criminal groups, which entails the adoption of appropriate legislative measures. Identifying the latency level of transnational crimes will make it possible to assess the efficiency of the existing sets of measures against it, as well as to formulate recommendations on improving the system of legislative measures to prevent the activities of transnational criminal organizations. A gap in the study can be attributed to the insufficient amount of statistical information on the analyzed crime. The novelty of the research lies in the comprehensive analysis of the current state of transnational organized crime.

The Central Asian states’ role in the world mining industry

The growing needs of mankind for minerals predetermine a systematic increase in the scope of mining operations. However, it is known that mineral resources are not evenly distributed in the bowels of the earth; therefore, due to their production, some regions of our planet can significantly outstrip other regions in their technical and, as a result, economic development; hence, the constant need to extract more minerals in order to develop the domestic industry and to strengthen the economy. This paper is devoted to the Central Asian states, their internal structure, economic integration into the world economy, and the mining sector development as the basis of a successful model for the development of the country as a whole. The study summarizes and analyzes the political system and socio-economic conditions in the Central Asian states. It presents a brief overview of the scale of mining operations; provides information about the mining industry structure in each country and the proceeds from its sales. Taking the Central Asian states as an example, we demonstrate the importance of the mining sector as an integral part of a country’s domestic economic structure.

Stratum temperature recovery considering groundwater advection in periodic operations of deep borehole heat exchangers

• Effect of groundwater advection on stratum temperature recovery of DBHE is studied. • Thermal impact scope of long-term and periodic operations is involved. • Critical Darcy velocity conducive to DBHE durability is discovered. • Multiple low-temperature valleys occur when the critical Darcy velocity is reached. During periodic operations of the deep borehole heat exchanger (DBHE), stratum temperature recovery is significantly affected by groundwater advection, but it has not been fully addressed. In this study, the stratum temperature recovery of long-term and periodic operations of DBHE is quantitatively analyzed via an improved analytical model developed in our previous work. To characterize its dependence on Darcy velocity, recovery rate, quasi-equilibrium time, and thermal impact scope are accordingly defined. Sensitivity analyses of thermal conductivity and thermal dispersion are also conducted. The results show that the recovery rate increases with Darcy velocity but varies slightly with heat extraction power inside the borehole. There is a critical Darcy velocity in periodic operations. When the groundwater advection velocity reaches the critical value, stratum temperature at the borehole wall gets close to its initial state after every recovery period, and multiple low-temperature valleys downstream of the groundwater advection occur. The greater thermal conductivity of medium and thermal dispersivity can result in the higher critical Darcy velocity. The thermal impact scope of the DBHE decreases overall when Darcy velocity increases, while the downstream thermal impact radius has a sharp increase for low Darcy velocities before the decline.

Dental Implant Navigation System Based on Trinocular Stereo Vision.

Traditional dental implant navigation systems (DINS) based on binocular stereo vision (BSV) have limitations, for example, weak anti-occlusion abilities, as well as problems with feature point mismatching. These shortcomings limit the operators’ operation scope, and the instruments may even cause damage to the adjacent important blood vessels, nerves, and other anatomical structures. Trinocular stereo vision (TSV) is introduced to DINS to improve the accuracy and safety of dental implants in this study. High positioning accuracy is provided by adding cameras. When one of the cameras is blocked, spatial positioning can still be achieved, and doctors can adjust to system tips; thus, the continuity and safety of the surgery is significantly improved. Some key technologies of DINS have also been updated. A bipolar line constraint algorithm based on TSV is proposed to eliminate the feature point mismatching problem. A reference template with active optical markers attached to the jaw measures head movement. A T-type template with active optical markers is used to obtain the position and direction of surgery instruments. The calibration algorithms of endpoint, axis, and drill are proposed for 3D display of the surgical instrument in real time. With the preoperative path planning of implant navigation software, implant surgery can be carried out. Phantom experiments are carried out based on the system to assess the feasibility and accuracy. The results show that the mean entry deviation, exit deviation, and angle deviation are 0.55 mm, 0.88 mm, and 2.23 degrees, respectively.

Long-Lived Room Temperature Phosphorescence Crystals with Green Light Excitation.

Long-lived room temperature phosphorescence (RTP) materials are promising for applications in various fields including security information, medical diagnostics, and molecular imaging because of their unique optical properties. Previous RTP materials are mainly excited by ultraviolet light, while synthesizing long-lived RTP materials with visible-light-excitation remains a challenge. In particular, long-lived RTP materials that can be excited by green light are rare. Herein, a feasible and concise chemical strategy for constructing hydrogen-bonded frameworks in an aqueous environment is developed to fabricate large-size, green-light-excited, and excitation-dependent long-lived RTP carbon dot crystals (m,p/CDs-ME). The RTP performance of the crystals exhibits strong excitation wavelength dependence, leading to a full range of visible-light tuning from blue to red. Importantly, the maximum excitation wavelength of the RTP crystals is around 500 nm, thus successfully realizing green light excitation. m,p/CDs-ME presents long-lived phosphorescence (130 ms) under 500 nm excitation in aqueous solution, making it highly suitable for dopamine detection. This work not only provides a general guideline for the development of large size long-lived RTP crystals but also extends the operation scope of long-lived RTP materials in the detection of biomarkers by visible light excitation.

Revascularization Using Lesion Sterilization and Tissue Repair: A Case Report

Clinicians encounter a variety of scenarios in which a permanent tooth has been damaged by trauma, followed by peri-radicular alteration, and is beyond the scope of typical endodontic operations to save. Because of the limited root length, it is difficult to keep a permanent tooth with an open apex. In today's world of modern dentistry, a new treatment option that is less intrusive and time-consuming could be advantageous to both the patient and the physician. The use of lesion sterilization and tissue repair for pulp revascularization is presented in this case report.

Minimally invasive surgical management of intraligamentous leiomyomas made ridiculously easy

To describe a minimally invasive systematic surgical approach to manage large intraligamentous leiomyomas. Intraligamentous myomas account for 6% of all leiomyomas according to Sizzi et al. Ambrosio et al found that transvaginal ultrasound has a sensitivity and specificity of 52% and 93%, respectively, for the diagnosis of intraligamentous leiomyomas. The surgical approach to these patients is discussed with easy to replicate steps highlighted in this video. Two cases of symptomatic women with intraligamentous myomas are described in this video, one measuring 8 cm and the other 6 cm in largest diameter. Both patients underwent an uncomplicated total robotic hysterectomy, bilateral salpingectomy, and cystoscopy. EBL was 50 ml and 25 ml, respectively. Key take home steps are as follows: 1. Perform a systematic evaluation of the abdomen and pelvis confirming location of bilateral ureters 2. Coagulate and transect the round ligaments 3. Open anterior and posterior broad ligament leaflets of the broad ligament to reveal the colpotomy cup 4. Skeletonize uterine vessels 5. Peel the intraligamentous myoma out of the pelvis and towards the operative scope 6. Coagulate and transect the uterine vessels above the colpotomy cup 7. Perform colpotomy 8. Perform a sharp vaginal morcellation or in bag morcellation as appropriate based on individual patient characteristics In conclusion, the incidence of leiomyomas has been reported to be as high as 80% by age 50. Only 6% of leiomyomas are intraligamentous myomas. This video reviews easy to replicate steps to successfully navigate the pelvis in the presence of intraligamentous myomas.

Data-driven incentive alignment in capitation schemes

This paper explores whether big data, taking the form of extensive high dimensional records, can reduce the cost of adverse selection by private insurers in government-run capitation schemes, such as Medicare Advantage. We argue that using data to improve the ex ante precision of capitation regressions is unlikely to be helpful. Even if types become essentially observable, the high dimensionality of covariates makes it infeasible to precisely estimate the cost of serving a given type: big data makes types observable, but not necessarily interpretable. This gives an informed private operator scope to select types that are relatively cheap to serve. Instead, we argue that data can be used to align incentives by forming unbiased and non-manipulable ex post estimates of a private operator’s gains from selection.

Consolidation or multiplicity in supply logistics for health commodities?

Public health-sectors of most low- and middle-income countries (LMICs) run a central medical stores (CMS) model that is monopolistic in character. Concerns raised about monopolistic CMS arrangements stress the need to encourage cost-reducing efforts and improve service levels (outputs) by having multiple competing logistics institutions. This paper examines the desirability of consolidation or multiplicity in supply logistics by focusing on the task of inventory management (that is, distribution, storage and warehousing). The paper uses theory and historical evidence to describe and suggest a desired form of multiplicity in LMICs. Consolidation shouldn't progress to the point of monopoly and multiplicity doesn't mean having an infinite number of logistics institutions. A limited number (2−10) of logistics institutions, that are full-line and national in their scope and scale of operations, should be enough to provide choice, support competition and minimize the risk of supply disruptions. Health policy and planning in LMICs should explore ways of turning existing logistics institutions in the public, private and non-governmental sectors into a multiplicity of types that are capable of assuring uninterrupted supplies of health commodities.

Energy-Efficient Cooperative Caching for Information-Centric Wireless Sensor Networking

Although information-centric networking (ICN) can boost the performance of sensor data delivery in wireless sensor networks (WSNs), its energy efficiency may be significantly impaired due to the receiver-driven request-response transmission model. ICN sensors have to keep long-time active mode to wait for the requests that may arrive at any time, resulting nontrivial energy waste for energy-constrained WSNs. An intuitive method to conserve energy is to schedule partial nodes to fall asleep, but at the cost of extra data fetching delay. In this work, we investigate multihop cooperative caching for green WSN over receiver-driven ICNs. By leveraging regional caches, not only can the energy be saved, but also the data fetching delay can be reduced. We formulate those two cooperation gains and capture the tradeoff between energy saving and delay reduction. Based on the optimal tradeoff, we present a solution of scoped multihop cooperative caching and elaborate a green cooperation policy for each sensor to determine its operation scope and conduct a proper cooperation decision. Our simulation results show that our proposed multihop cooperative caching can save more than 91.0% energy and achieve 28.9% delay reduction than the basic ICWSN, and also reduce 60.2% energy consumption than the existing cooperative caching schemes.

Risk factors for acute exacerbation of interstitial lung disease following lung cancer resection: a systematic review and meta-analysis.

OBJECTIVESThe aim of this study was to investigate the risk factors for acute exacerbation (AE) of interstitial lung disease (ILD) following lung cancer resection. METHODSWe performed a literature screening on the databases including PubMed, Embase, Ovid MEDLINE® and the Web of Science for related studies published up to January 2021. Eligible studies were included and data on risk factors related to postoperative AE were extracted. All analyses were performed with random-effect model.RESULTSA total of 12 studies of 2655 lung cancer patients with ILD were included in this article. The meta-analysis indicated that male [odds ratios (ORs) = 1.78, 95% confidence interval (CI): 1.02–3.11, P = 0.041], usually interstitial pneumonia pattern on CT (OR = 1.52, 95% CI: 1.06–2.17, P = 0.021), Krebs von den Lungen-6 [standardized mean difference (SMD) = 0.50, 95% CI: 0.06–0.94, P = 0.027], white blood cell (SMD = 0.53, 95% CI: 0.12–0.93, P = 0.010), lactate dehydrogenase (SMD = 0.47, 95% CI: 0.04–0.90, P = 0.032), partial pressure of oxygen (weighted mean difference = −3.09, 95% CI: −5.99 to −0.19, P = 0.037), surgery procedure (OR = 2.31, 95% CI: 1.42–3.77, P < 0.001) and operation time (weighted mean difference = 28.26, 95% CI: 1.13–55.39, P = 0.041) were risk factors for AE of ILD following lung cancer resection.CONCLUSIONSWe found that males, usually interstitial pneumonia pattern on CT, higher levels of Krebs von den Lungen-6, lactate dehydrogenase, white blood cell, lower partial pressure of oxygen, greater scope of operation and longer operation time were risk factors for AE of ILD following lung cancer resection. Patients with these risk factors should be more prudently selected for surgical treatment and be monitored more carefully after surgery.

The Hungarian monument protection from 1957 to 1990 through the lens of its professional journal

The nationwide monument protection system was (re-)established in Hungary in 1957 and operated uninterruptedly during the previous political system. Even though by now both the profession and its institutional system has been transformed numerous times, the dedicated professional journal, titled “Monument Protection”, has been continuously published since 1957. It was first published by the Union of Hungarian Architects and from 1960 the National Monument Protection Inspectorate (OMF) was the main publisher until the end of the researched period in 1990. It describes and discusses case studies, theoretical investigations and informs colleagues and the interested nationwide audience about the international norms and trends in that field. This contribution looks at the first circa three decades (1957-1990) of this journal as a basis to investigate the profession in Hungary, its operational scope as well as its national and international status. Melinda Harlov-Csortán – The Hungarian monum ent... 59 This investigation contributes not just to exploration of an important historical period through a specialized profession but to understanding of our contemporary built environment and the views and concepts behind them as well. The research process involves analysis of printed materials (such as policies or conference publications) as well as interviews with members of the profession. The current contribution analyzes the first 33 years of the publication by looking at both its content, structure and language. Comparative and discourse analysis were conducted to understand both the given period of the Hungarian profession and the role of the journal in question. The aim of the article is to discuss the self-representation of the Hungarian monument protection profession during the researched period (1957-1990) not just by presenting the history of the field but also by investigating tasks and challenges that Hungarian monument professionals identified themselves. ‟Monument Protection” serves also as a great basis for comparative analysis together with other Hungarian publications or even as a basis of international comparison with alike foreign journals.

SURGICAL TREATMENT OF PATIENTS WITH EXTRAORGANIC TUMORS OF THE PELVIC LOCALIZATION WITH INVASION OF THE ILIAC VESSELS

The aim of our study was to determine the indications for expanding the scope of operations in patients with pelvic extraorgan local formations.&#x0D; Materials and methods. The results of surgical treatment of 7 patients with nonorgan tumors of the pelvic localization, who underwent resection on the main vessels in connection with their involvement in the tumor process, are presented.&#x0D; Results and discussion. A total of 7 interventions were performed on the iliac arteries — 2 resections with an end-to-end anastomosis and 5 prostheses (one case — the aorta resection with reconstruction with a bifurcation prosthesis).&#x0D; Patients with pelvic extraorgan tumors are a special cohort of patients, due to the presence of several organs in a narrow space, which inevitably causes them to fit snugly to the tumor. Locally advanced tumor process in extraorganic tumors involving the main vessels of the pelvis and adjacent organs is not a reason to refuse surgery, and despite the complications, repeated recurrences and previous operations, are well tolerated by patients. This is especially important due to the lack of a real alternative to surgical treatment of this group of patients.&#x0D; Conclusions. Surgical intervention in the treatment of pelvic inorganic tumors involving the main vessels is the only radical method of treatment. Invasion of the main arterial and venous vessels is not a contraindication to surgery in patients with pelvic tumors. Combined angioplastic interventions allow to achieve a long without recurrent period even after cytoreductive operations.

La recherche savante de la vérité par différents critères dans l’histoire des doctrines retracée par Sextus Empiricus

The purpose of this article is, firstly, to study the meaning and scope of the mental operation exposed in the search for criteria and, secondly, to show the convergences and divergences between philosophical schools in the choice of criteria. This mental operation is involved in the decision or judgment. Taking this operation for the center of gravity of this article, we divided this work into two sections. The first is to study the uses of the term "criterion". Then, it's a question of analyzing the different criteria that the Greek scientists of Antiquity use to seek either the truth, the relative or the subjective. These are the dogmatics. We also analyze the skeptics' practical "criterion" that consists of following appearances and observing the rules of daily life. We thus notice that each philosophical school uses the "criterion", and the use that it makes of it determines its characteristics. This is why we've different philosophers: the dogmatists and the skeptics who diverge very often on many points and sometimes converge on certain points

MANAGEMENT REPORT: INFORMATION AND REGULATORY PROVISIONS BY THE SUBJECTS OF FORMATION

In terms of harmonization of domestic legislation with the EU legal field, an important area of regulation is accounting, as an information base for the economic development of individual enterprises and economies, and the European region and the world economy as a whole, especially given the informatization and globalization of socio-economic processes. However, the lack of experience in generating non-financial reports, especially in medium-sized enterprises and financial institutions belonging to micro and small enterprises, and the non-regulated form of the report somewhat complicate the process, so the research of the structure and information content of the management report is relevant. The article examines the legal regulation of the report on management in Ukraine, the main areas of information coverage, depending on the scope of operation, size, and nature of capital formation. The list of basic information to be disclosed in the management report is determined for enterprises (except banks, budgetary institutions, micro-enterprises, and small enterprises), for joint-stock companies, for financial institutions with share capital, for banks and banks with share capital. The difference in the content of the management report of all these entities arises due to differences in the composition of users of information and their needs for it, to make management or other decisions. Enterprises that prepare financial statements by international reporting standards may prepare a management report by domestic law. Any form of management report permitted by IFRS Practice Statement 1 “Management Commentary” In general, the history of non-financial reporting has proven its financial effectiveness, but at the same time, there are some problems associated with its formation. First, due to the lack of a regulated form and high dynamism of the external environment, there is a problem of the content of the report, which would meet the needs of stakeholders and work on a positive image of the company. Secondly, there is the problem of verifying the management report and confirming its compliance with the financial statements of the enterprise, especially in the non-financial component. And, thirdly, another problem that arises from the second – is the tax consequences of publishing a management report, they can be both negative and positive. All these issues need further research and proposals to address them.

What are public development banks and development financing institutions ? ——qualification criteria, stylized facts and development trends

Public development banks and development financing institutions are experiencing renaissance worldwide, but systematic academic research is patchy. The bottleneck mainly boils down to the lack of data, which has constrained the meaningful research on the rationales of establishing PDBs and DFIs and reasons for their successes and failures. To fill the gap, we aim to answer the fundamental question of “what PDBs and DFIs are” by proposing five qualification criteria, i.e., being a stand-alone entity, using the fund-reflow-seeking financial instruments as main products and services; funding sources going beyond the periodic budgetary transfers; the proactive public policy orientation, and government steering of their corporate strategy. Furthermore, we have systematically identified over 500 PDBs and DFIs that meet the five qualification criteria worldwide. Based on the first-hand data collection, we present the stylized facts (including ownership structure, official mandate, geographical scope of operation, asset size, and income groups) and development trends of worldwide PDBs and DFIs. We hope that this first global database on PDBs and DFIs can lay the foundation for the original academic and policy research.

Determinants of bank risk governance structure: A cross-country analysis

This study investigates the determinant of the bank risk governance structure. Using bank-level panel data of 104 commercial banks in 10 ASEAN countries between 2002–2019, we find that the risk governance structure (including audit committee size, audit committee independence, financial and accounting experts on the audit committee, audit committee meeting frequency, risk committee existence, and external audit quality) relates positively to a bank’s scope of operation and monitoring benefit, but negatively to the monitoring cost and CEO negotiation power. However, these relations are different between banks with high and low levels of risk and banks in countries with different institutional qualities. Our findings provide important policy implications for designing a risk governance structure in the banking sector.

Ionizing Radiation Monitoring Technology at the Verge of Internet of Things.

As nuclear technology evolves, and continues to be used in various fields since its discovery less than a century ago, radiation safety has become a major concern to humans and the environment. Radiation monitoring plays a significant role in preventive radiological nuclear detection in nuclear facilities, hospitals, or in any activities associated with radioactive materials by acting as a tool to measure the risk of being exposed to radiation while reaping its benefit. Apart from in occupational settings, radiation monitoring is required in emergency responses to radiation incidents as well as outdoor radiation zones. Several radiation sensors have been developed, ranging from as simple as a Geiger-Muller counter to bulkier radiation systems such as the High Purity Germanium detector, with different functionality for use in different settings, but the inability to provide real-time data makes radiation monitoring activities less effective. The deployment of manned vehicles equipped with these radiation sensors reduces the scope of radiation monitoring operations significantly, but the safety of radiation monitoring operators is still compromised. Recently, the Internet of Things (IoT) technology has been introduced to the world and offered solutions to these limitations. This review elucidates a systematic understanding of the fundamental usage of the Internet of Drones for radiation monitoring purposes. The extension of essential functional blocks in IoT can be expanded across radiation monitoring industries, presenting several emerging research opportunities and challenges. This article offers a comprehensive review of the evolutionary application of IoT technology in nuclear and radiation monitoring. Finally, the security of the nuclear industry is discussed.