Complexity Bounds for Block-IPs

We consider integer programs (IPs) with a certain block structure, called two-stage stochastic. A two-stage stochastic IP is an integer program of the form $\min\{c^Tx \mid Ax=b,\, \ell\leq x\leq u,\, x\in \mathbb{Z}^{s + nt}\}$ where the constraint matrix $A\in \mathbb{Z}^{rn \times s+tn}$ consists of blocks $A^{(i)} \in \mathbb{Z}^{r\times s}$ on a vertical line and blocks $B^{(i)}\in \mathbb{Z}^{r\times t}$ on the diagonal line aside. We improve the bound for the Graver complexity of two-stage stochastic IPs. Our bound of $3^{O(s^s(2r||A||_\infty+1)^{rs})}$ reduces the dependency from $rs^2$ to $rs$ and is asymptotically tight under the exponential time hypothesis in the case that $r=1$. The improved Graver complexity bound stems from improved bounds on the intersection for a class of structurally rich integer cones. Our bound of $3^{O(d\Delta)^d}$ for dimension $d$ and absolute entries bounded by $\Delta$ is independent of the number of intersected integer cones. We investigate special properties of this class, which is complemented by the fact that these properties do not hold for general integer cones. Moreover, we give structural characterizations of this class that admit their use for two-stage stochastic IPs

Interwest Construction, a Utah corporation v. R. Roy Palmer and Val W. Palmer, dba A.H. Palmer and Sons : Reply Brief

APPEAL FROM THE FIRST JUDICIAL DISTRICT COURT OF CACHE COUNTY, JUDGE LOW Priority Number 15

Interwest Construction, a Utah corporation v. R. Roy Palmer and Val W. Palmer, dba A.H. Palmer and Sons : Reply Brief

APPEAL FROM THE FIRST JUDICIAL DISTRICT COURT OF CACHE COUNTY, JUDGE LOW Priority Number 15

A CleanRoom approach to bring your own apps

Today, on mobile devices such as smartphones and tablets, hundreds of thousands of software apps provide useful services to users. Users use these apps to search and browse the web, perform financial transactions, emailing, among other functions. Besides, these apps use cloud services which gives the users the flexibility to access them from anywhere and from any device. Because of the rich functionality of these apps and ease of use of mobile devices, users (employees) often want to use their devices and preferred apps at their workplace. However, these apps not only pose risk to user's private data but also to enterprise data, when users use them within an enterprise network. For one thing, these apps come from hundreds and thousands of different app publishers, where all of them may not be trustworthy. Second, apps often need user's private data such as location, contact list, photos among others and use remote cloud to carry out their operations. In the process apps may leak a user's private or enterprise confidential data to a third party. Current practices to prevent such leaks through user enabled app permissions fall short because often user does not understand these permissions. Besides, even if a company's "Bring Your Own Device" (BYOD) policies mitigate the risk of device compromise with enterprise-approved password policies, remote wipe capabilities, and OS security upgrade policies, the apps on those devices pose their own risks. This thesis presents CleanRoom, a new app platform that prevents apps from leaking the data entrusted to them. It does not rely on users to make good decisions about Privacy, and enables enterprises to allow its employees to use their own devices and bring their preferred apps to work.Computer Science

Adsorption of Zinc from Aqueous Solution by Using Natural Adsorbents

Several studied have pointed out natural adsorbent efficiently in the removal of heavy metal ion present in aqueous solution. Contact time, pH and adsorbent concentration seem to be the major operating parameters in the metal concentration control. The mechanisms of interactions between metal and solid are a function of pH and are found to be precipitation, adsorption or ion exchange. The objectives ofthis work were to study the removal of heavy metal in water by sorption onto date seeds, clove, star anise and cinnamon. This research was done on lab scale experiments to study efficiency of date seeds, cloves, star anise and cinnamon powder in removing heavy metals from aqueous solution. Solutions of varying concentrations of heavy metals of 1,10 and 100 ppm were prepared and added with adsorbent than shake in orbital shaker for 1, 3, 6 and 24 hours. Next, the sample of solution been filtered to remove insoluble material and analyzed for concentration of heavy metal ions using spectrophotometer. Concentrations of adsorbent also were varied to study the removal efficiency of heavy metals. Final metal ion concentrations in solution and adsorption isotherm were determined. Base on the experiment, date seeds, clove, star anise and cinnamon shown 92, 91, 82 and 87 percentage of zinc removal. While adsorption capacity was obtained 1.58 mg/g for date, 3.03 mg/g for clove, 0.68 mg/g for star anise and 5.44 mg/g for cinnamon. Kf value for date seed, clove, star anise and cinnamon was 1.41, 3.5, 0.54 and 3.57. While the value for n for date seeds, clove, star anise and cinnamon was 1.48, 1.06, 0.54 and 3.57. The pH for clove, star anise and cinnamon were in range of 4 to 7 pH. While date seeds were in range of 5 to 8 pH. All the results is consistent with the Freundlich parameter that indicate, the smaller the value of 1/n means that adsorption bond is strong

Effect of kenaf fiber on the mechanical properties of reinforced concrete structures

There is currently a great deal of interest in developing technology using natural organic fiber materials in cement composites. Kenaf is one of the organic fiber that has potential to be used in concrete. Kenaf fiber has many advantages such as affordability, renewability, recyclability, and biodegradability. Its tensile properties are comparable to those of other natural fibers, such as jute, flax and bamboo. Fiber reinforced concrete (FRC) was introduced to the industry to improve concrete properties and to prevent the cracking of reinforced concrete members. Nevertheless, the limited use of FRC in load-bearing structures seems to be due to a lack of accepted design mixes and guidelines. This study investigates the physical and mechanical properties of Kenaf fiber reinforced concrete (KFRC) and its structural behaviour as concrete beam under static loads. This study was carried out mainly by experiment. The experiments were conducted according to relevant American Standards (ASTM) and British Standards (BS), as well as recommended methods from past researchers. A number of parameters were observed from the experiment, such as physical properties (colour, fiber distribution in concrete, surface morphology, density, aspect ratio, weight loss and water absorption), properties of fresh KFRC (slump, compacting factor and vebe time), properties of hardened KFRC (ultrasonic pulse velocity, rebound hammer, density, compressive strength, splitting tensile strength, flexural strength, static modulus of elasticity and equivalent compressive strength) and performance of KFRC when used as beams under flexural loadings (ultimate load, deflection, cracking, steel strain, concrete strain, bonding between concrete and steel reinforcement and neutral axis). A total of 1300 concrete specimens (cube, cylinder and prism) and 7 beam specimens were casted and tested in this study. A theoretical model for the analysis and design of Kenaf fiber reinforced concrete materials and structural beam elements was proposed and evaluated. Results show that the presence of Kenaf fiber in concrete improved the properties such as splitting tensile strength, flexural strength and ultimate load of beam. However, it reduced the concrete properties if the fiber used was over the limit, the properties such as density, slump, compacting factor, vebe time, ultrasonic pulse velocity, rebound hammer, compressive strength, static modulus of elasticity and equivalent compressive strength. KFRC only can perform well under the suitable fiber to cement volume fractions of up to 0.75%. Fiber length did not affect concrete performance. The performance of KFRC was greatly influenced by the distribution and orientation of Kenaf fibers in concrete. Control and handling during the mixing process of KFRC was a major factor in producing quality concrete. Finally the use of Kenaf fiber as reinforcement in concrete is highly recommended based on improvements in material strength and structural performance

Adsorption of Zinc from Aqueous Solution by Using Natural Adsorbents

Several studied have pointed out natural adsorbent efficiently in the removal of heavy metal ion present in aqueous solution. Contact time, pH and adsorbent concentration seem to be the major operating parameters in the metal concentration control. The mechanisms of interactions between metal and solid are a function of pH and are found to be precipitation, adsorption or ion exchange. The objectives ofthis work were to study the removal of heavy metal in water by sorption onto date seeds, clove, star anise and cinnamon. This research was done on lab scale experiments to study efficiency of date seeds, cloves, star anise and cinnamon powder in removing heavy metals from aqueous solution. Solutions of varying concentrations of heavy metals of 1,10 and 100 ppm were prepared and added with adsorbent than shake in orbital shaker for 1, 3, 6 and 24 hours. Next, the sample of solution been filtered to remove insoluble material and analyzed for concentration of heavy metal ions using spectrophotometer. Concentrations of adsorbent also were varied to study the removal efficiency of heavy metals. Final metal ion concentrations in solution and adsorption isotherm were determined. Base on the experiment, date seeds, clove, star anise and cinnamon shown 92, 91, 82 and 87 percentage of zinc removal. While adsorption capacity was obtained 1.58 mg/g for date, 3.03 mg/g for clove, 0.68 mg/g for star anise and 5.44 mg/g for cinnamon. Kf value for date seed, clove, star anise and cinnamon was 1.41, 3.5, 0.54 and 3.57. While the value for n for date seeds, clove, star anise and cinnamon was 1.48, 1.06, 0.54 and 3.57. The pH for clove, star anise and cinnamon were in range of 4 to 7 pH. While date seeds were in range of 5 to 8 pH. All the results is consistent with the Freundlich parameter that indicate, the smaller the value of 1/n means that adsorption bond is strong

Studi Koordinasi Proteksi Arus Lebih Akibat Pemasangan Sisfcl (Saturated Iron-Core Superconducting Fault Current Limiter) Di Pabrik III Pt. Petrokimia Gresik

Meningkatnya pasokan kebutuhan daya listrik di PT. Petrokimia Gresik sehingga dilakukan pemasangan generator baru atau melakukan interkoneksi generator untuk menjaga kontinuitas pelayanan daya listrik. Akibat adanya interkoneksi generator maka arus hubung singkat akan semakin besar pada titik gangguan. Hal ini dapat melampaui device capability peralatan sehingga dapat merusak peralatan listrik yang berada di dekat titik gangguan. Arus gangguan hubung singkat pada switchgear utama di pabrik III HVS 65 melebihi device capability, dimana rating switchgear 100 kA peak, sedangkan arus hubung singkat 3 fasa ½ cycle sebesar 123.5 kA peak. Oleh sebab itu untuk membatasi arus gangguan hubung singkat tersebut digunakan suatu Saturated Ironcore Superconducting Fault Current Limiter (SISFCL). SISFCL ini dipasang pada transformator IBT01 yang merupakan sumber arus kontribusi terbesar ketika terjadi gangguan hubung singkat 3 fasa ½ cycle pada switchgear HVS 65. Pemasangan SISFCL dapat mengurangi besarnya arus hubung singkat pada HVS 65 dari 123.5 kA menjadi 98 kA peak. Pemasangan SISFCL menunjukkan arus hubung singkat semakin berkurang sehingga mengakibatkan terjadinya perubahan koordinasi proteksi rele arus lebih pada pabrik III. Studi koordinasi dilakukan untuk mengetahui apakah sistem pengaman bekerja dengan baik. Hasil analisa hubung singkat serta studi koordinasi proteksi akan ditampilkan dalam bentuk kurva time current characteristic (TCC). ============================================================================================ Increase demand of electric power at PT. Petrokimia Gresik so need the installation of new generator or interconnection generator to maintain the continuity of the electric power service. Due to the interconnection of the generator short circuit current will be greater at the point of interruption. It can exceed the device capability of equipment so can damage electrical equipment near the point of the interruption. Short circuit fault current at the main switchgear on plant III HVS 65 exceed device capability, maximum value of switchgear is 100 kA, while the ½ cycle short circuit 3 phasa current of 123.5 kA. Therefore to limit the short circuit current is used Saturated Iron-core Superconducting Fault Current Limiter (SISFCL). SISFCL will be installed in the transformator IBT01 which is the current source of the greatest contribution in the event of ½ cycle short circuit 3 phasa in the switchgear HVS 65. Installation of SISFCL can reduce the amount of short circuit current on the switchgear HVS 65 of 123.5 kA to 98 kA peak. Installation of SISFCL shows decreasing of short circuit current, so causes changes the overcurrent protection coordination on plant III. Study overcurrent protection coordination is used to determine if security system works well. the result of short circuit analysis and study overcurrent protection coordination will appear in time current curve characteristic (TCC)