Autocorrelated process control: Geometric Brownian Motion approach versus Box-Jenkins approach

Existing of autocorrelation will bring a significant effect on the performance and accuracy of process control if the problem does not handle carefully. When dealing with autocorrelated process, Box-Jenkins method will be preferred because of the popularity. However, the computation of Box-Jenkins method is too complicated and challenging which cause of time-consuming. Therefore, an alternative method which known as Geometric Brownian Motion (GBM) is introduced to monitor the autocorrelated process. One real case of furnace temperature data is conducted to compare the performance of Box-Jenkins and GBM methods in monitoring autocorrelation process. Both methods give the same results in terms of model accuracy and monitoring process control. Yet, GBM is superior compared to Box-Jenkins method due to its simplicity and practically with shorter computational time

Prikaz bolesnika s ektopičnom sekrecijom ACTH i znacima Cushingova sindroma

Ectopic ACTH secretion was the first paraneoplastic endocrine syndrome described in the literature. The most common tumors associated with ectopic ACTH production are small-cell lung cancer and atypical carcinoids. High cortisol levels have also been described in patients with adenocarcinoma and large-cell carcinoma of the lung, other carcinoid tumors, thymoma, neural crest tumors, medullary carcinoma of the thyroid, and bronchial adenomas. Patients rarely live long enough for frank Cushing’s syndrome to develop. A 30-year-old male is described, who was admitted to endocrinology ward for clinical features of Cushing’s syndrome. Outpatient examination showed high levels of plasma cortisol on several occasions, without suppression of night dexamethasone test. Laboratory tests performed during his hospital stay showed an increased level of serum cortisol without suppression of night dexamethasone test, increased level of ACTH, and decreased testosterone level, increased 17 OHCS in urine. CT scan of adrenal and pituitary glands, and chest x-ray were normal. The patient was discharged with an appointment made for surgical exploration of the pituitary gland. Transnasal selective partial hypophysectomy was performed, however, excisional biopsy showed no microadenoma while the symptoms persisted postoperatively. The patient received TCT hypophysis in a maximal dose, and elevated ACTH level was found to persist after 37 days of treatment. One year later, the patient was readmitted for persistent cushinoid appearance. After complete investigations for ectopic ACTH secreting tumor, chest x-ray showed an infraclavicular, circular, sharply demarcated inhomogeneous lesion of the left lung, 2x3 cm in size. Three months later, lobectomy was performed and pathohistologic examination pointed to a carcinoid (argentaffinoma). During hospitalization, the symptoms of Cushing’s syndrome regressed. In conclusion, CRH test which usually distinguishes between hyperadrenocorticism associated with ectopic ACTH secretion and hypersecreting adrenal tumors is sometimes misleading because of the large overlap in normal and abnormal responses. In this case, chest or abdominal CT scan or MRI should be performed, because these are the most common sites of ectopic ACTH secreting tumors.Prvi paraneoplastični endokrini sindrom opisan u literaturi bila je ektopična sekrecija ACTH. Najčešći tumori udruženi s ektopičnom sekrecijom ACTH su mikrocelularni karcinom pluća i atipični karcinoidi. Visoke razine kortizola opisane su i u bolesnika s adenokarcinomom i karcinomom velikih stanica pluća, karcinoidima, timomom, tumorima neuralnog grebena, medularnim karcinomom štitnjače i bronhalnim adenomom. Bolesnici rijetko žive dovoljno dugo da razviju manifestan Cushingov sindrom. Opisan je slučaj 30-godišnjeg muškarca koji je primljen na odjel s kliničkim znacima Cushingova sindroma. Ambulantno ispitivanje pokazalo je u više navrata visoke razine kortizola koji se nije snižavao u kratkom deksametazonskom testu. Tijekom boravka u bolnici je uz već navedeno uočena visoka razina ACTH, sniženi testosteron i povišen 17 OHCS u mokraći. CT nadbubrežnih žlijezda i Rtg snimka prsnog koša bili su uredni. Bolesnik je otpušten uz dogovor za kiruršku eksploraciju hipofize, te je učinjena transnazalna djelomična hipofizektomija. Ekscizijska biopsija nije pokazala znakove tumora, a klinički znaci Cushingova sindroma ustrajali su nakon operacije. Bolesnik je podvrgnut radioterapiji hipofize u maksimalnoj dozi, međutim, vrijednosti ACTH su još uvijek bile povišene. Nakon godinu dana bolesnik je ponovno primljen na odjel zbog ustrajnih znakova Cushingova sindroma. Nakon potpune obrade u smislu traženja ektopične sekrecije ACTH, snimka prsnoga koša pokazala je infraklavikularno oštro ograničenu, nehomogenu sjenu u plućima, veličine 2x3 cm. Tri mjeseca kasnije učinjena je lobektomija, a patohistološki nalaz je ukazao na karcinoid (argentafinom). Tijekom hospitalizacije simptomi Cushingova sindroma su se povukli. U zaključku, CRH test koji obično razlikuje hiperadrenokorticizam udružen s ektopičnom sekrecijom ACTH i hipersekreciju iz adrenalnih tumora, ponekad je neprikladan zbog značajnog preklapanja u normalnom i abnormalnom odgovoru. U tom slučaju, nužan je detaljan pregled prsnoga koša i trbuha, budući da su to najčešća sijela tumora koji ektopično izlučuju ACTH

Effects of indoor air quality on the occupant's health and productivity in an office building

Indoor Air Quality (IAQ) is an important parameter in deciding the status of Sick Bulding Syndrome (SBS). Poor IAQ which leads to SBS can result in adverse effect on the health of the occupant which causing lower productivity. This study was conducted to establish correlation between IAQ and employee’s productivity. Five parameters of IAQ which include air velocity, air temperature, relative humidity, particulate matters ≥ 0.3 μm and CO2 were considered in this study. The values of these parameters were measured using Davis Anemometer, Particle Counter GT 521 and YES Plus LGA Meter. The measured data were then used as an input data for simulation model of the room using Comsol Multiphysics software. The simulation generated the indoor air velocity of the room and particle distribution. For validation purpose, only the predicted velocity was compared with the measured value, and found that the percentage difference were in the range of 1.5% to 8.45% (below than 10%). Once the model had been validated, the parametric study of air supply inlet position was conducted on the model and found that the position of air supply inlet with x = 2.5 ft, y = 10 ft and H = 6.5 ft give the most efficient air distribution model for diluting the impurities due to the particulate. The questionnaire survey distributed amongst the occupants of the room showed that the occupants were less satisfied (75%) with the IAQ which can lead to SBS problem. The analysis of correlation between IAQ and occupant's productivity depicted that both of the factors were correlated with Rank-Spearman value of 0.648. This study serves as a good platform in assessing IAQ based on the modelling and simulation approach

Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

Tribology performance of TiO2-SiO2/PVE nanolubricant at various binary ratios for the automotive air-conditioning system

Tribological properties are crucial for air-conditioning system performance. The properties can be improved using nanolubricant. However, the effect of the binary ratio of hybrid nanolubricants on the tribological performance of automotive systems is limited in the literature. Therefore, the present study investigates the tribology performance of TiO2-SiO2 nanolubricants for application in automotive air-conditioning (AAC) systems. The dispersion of TiO2 and SiO2 into PVE lubricant was carried out using a two-step method. Subsequently, the dispersion stability was assessed ualitatively and quantitatively. The samples were characterised by a volume concentration of 0.010%, with variations in the mixture ratio of 20:80, 40:60, 50:50, 60:40, and 80:20. Coefficient of friction (COF) and wear scar diameter (WSD) values were determined using the Koehler Four ball Tribo Tester and Light Compound Microscopy. The investigation revealed that each sample experienced a reduction in COF, with the 40:60 ratio demonstrating the best ratio with the most significant decrease of 37.09%. At the same time, the COF decreased by 8.34%, 2.12%, 7.37%, and 15.11% for the nanolubricant samples at 20:80, 50:50, 60:40, and 80:20, respectively. The WSD evaluation showed that the 40:60 ratio has the lowest scar diameter of 0.0344 mm and a 37.09% wear rate decrease compared to pure lubricant. Each sample exhibits superior performance when evaluated for tribological characteristics and performance, particularly in the case of nanolubricants with the 40:60 ratio. The TiO2-SiO2/PVE, characterised by a volume concentration of 0.010%, has remarkable efficacy across different binary ratios, making it highly recommended with a 40:60 ratio for lubricating AAC compressor systems

The future of Malay–Chinese relations in Malaysia

In this chapter, the Malay–Chinese relation is examined by considering the history and nature of the relationship, the ensuing intergroup conflict, and the steps taken by the government and civil society groups to address the conflict. Finally, a psychocultural approach to building peace between the two groups is proposed

Using Quantum Confinement to Uniquely Identify Devices

Modern technology unintentionally provides resources that enable the trust of everyday interactions to be undermined. Some authentication schemes address this issue using devices that give unique outputs in response to a challenge. These signatures are generated by hard-to-predict physical responses derived from structural characteristics, which lend themselves to two different architectures, known as unique objects (UNOs) and physically unclonable functions (PUFs). The classical design of UNOs and PUFs limits their size and, in some cases, their security. Here we show that quantum confinement lends itself to the provision of unique identities at the nanoscale, by using fluctuations in tunnelling measurements through quantum wells in resonant tunnelling diodes (RTDs). This provides an uncomplicated measurement of identity without conventional resource limitations whilst providing robust security. The confined energy levels are highly sensitive to the specific nanostructure within each RTD, resulting in a distinct tunnelling spectrum for every device, as they contain a unique and unpredictable structure that is presently impossible to clone. This new class of authentication device operates with few resources in simple electronic structures above room temperature.Comment: 13 pages, 3 figure

Atomic-scale authentication using resonant tunnelling diodes

The rapid development of technology has provided a wealth of resources enabling the trust of everyday interactions to be undermined. Authentication schemes aim to address this challenge by providing proof of identity. This can be achieved by using devices that, when challenged, give unique but reproducible responses. At present, these distinct signatures are commonly generated by physically unclonable functions, or PUFs. These devices provide a straightforward measurement of a physical characteristic of their structure that has inherent randomness, due to imperfections in the manufacturing process. These hard-to-predict physical responses can generate a unique identity that can be used for authentication without relying on the secrecy of stored data. However, the classical design of these devices limits both their size and security. Here we show that the extensively studied problematic fluctuations in the current-voltage measurements of resonant tunnelling diodes (RTDs) provide an uncomplicated, robust measurement that can function as a PUF without conventional resource limitations. This is possible due to quantum tunnelling within the RTD, and on account of these room temperature quantum effects, we term such devices QUFs - quantum unclonable functions. As a result of the current-voltage spectra being dependent on the atomic structure and composition of the nanostructure within the RTD, each device provides a high degree of uniqueness, whilst being impossible to clone or simulate, even with state-of-the-art technology. We have thus created PUF-like devices requiring the fewest resources which make use of quantum phenomena in a highly manufacturable electronic device operating at room temperature. Conventional spectral analysis techniques, when applied to our QUFs, will enable reliable generation of unpredictable unique identities which can be employed in advanced authentication systems