Analisis Risiko Konstruksi Struktur Bore Pile Pada Proyek Dengan Metode Analytical Hierarchy Process (AHP)

ANALISIS RISIKO KONSTRUKSI STRUKTUR BORE PILE PADA PROYEK DENGAN METODE ANALYTICAL HIERARCHY PROCESS (AHP) (STUDI KASUS : PROYEK PERKUATAN LERENG KIRI KAKI BENDUNGAN JATIGEDE SUMEDANG ) Monica Tanskanovia Magna - 2016 Program Studi Teknik Sipil, Fakultas Teknik, Universitas Sebelas Maret Jl. Ir. Sutami 36A, Surakarta, Jawa Tengah 57126; Telp. 0271-634524; E-mail: [email protected] Abstrak - Kegiatan proyek tidak hanya struktur konstruksi gedung melainkan infrastruktur umum seperti konstruksi bendungan. Konstruksi ini merupakan konstruksi yang relatif besar dan fungsional sehingga membutuhkan pondasi sebagai media penahan tanah. Struktur bore pile termasuk jenis pondasi tiang dalam dimana proses pembuatannya dilakukan dengan mengebor tanah. Dalam pelaksanaannya, diperlukan analisis risiko untuk mengetahui berbagai faktor risiko dominan dan besar level risiko yang terjadi berdasarkan waktu dan biaya. Data yang digunakan adalah data primer berupa hasil wawancara dan penyebaran kuisioner terhadap 5 responden, diantaranya project manager, site commercial, site engineering, pengawas utama, dan pengawas lapangan dari pihak kontraktor. Analisis yang dilakukan menggunakan metode Analytical Hierarchy Process (AHP) untuk mencari bobot risiko, selanjutnya dilakukan perhitungan tingkat risiko (R) pada tiap-tiap sub risiko dengan hasil terbesar merupakan risiko dominan. Hasil analisis tersebut menghasilkan risiko dominan berdasarkan waktu dan biaya yaitu: hujan, produktivitas tenaga kerja tidak sesuai perkiraan, longsor, keruntuhan tanah permukaan di sekeliling lubang bor, subkontraktor kurang berkualitas, jalan akses kerja, tidak adanya informasi pengendalian waktu untuk memantau dan menganalisis kesalahan estimasi schedule yang mempengaruhi kinerja proyek, dan sistem pengendalian biaya yang lemah. Kata kunci : Struktur Bore Pile, Tingkat Risiko, Analisis Risiko, AH

Bistable states of quantum dot array junctions for high-density memory

We demonstrate that two-dimensional (2D) arrays of coupled quantum dots (QDs) with six-fold degenerate p orbitals can display bistable states, suitable for application in high-density memory device with low power consumption. Due to the inter-dot coupling of $p_x$ and $p_y$ orbitals in these QD arrays, two dimensional conduction bands can be formed in the x-y plane, while the $p_z$ orbitals remain localized in the x-y plane such that the inter-dot coupling between them can be neglected. We model such systems by taking into account the on-site repulsive interactions between electrons in $p_z$ orbitals and the coupling of the localized $p_z$ orbitals with the 2D conduction bands formed by $p_x$ and $p_y$ orbitals. The Green's function method within an extended Anderson model is used to calculate the tunneling current through the QDs. We find that bistable tunneling current can exist for such systems due to the interplay of the on-site Coulomb interactions (U) between the $p_z$ orbitals and the delocalized nature of conduction band states derived from the hybridization of $p_x$ / $p_y$ orbitals. This bistable current is not sensitive to the detailed band structure of the two dimensional band, but depends critically on the strength of $U$ and the ratio of the left and right tunneling rates. The behavior of the electrical bistability can be sustained when the 2D QD array reduces to a one-dimensional QD array, indicating the feasibility for high-density packing of these bistable nanoscale structures

Structural and electronic characterization of (2,3(3)) bar-shaped stacking fault in 4H-SiC epitaxial layers

Crystallographic, electronic, and energetic analyses of the (2, 3_3) [or (2, 3, 3, 3) in the standard Zhadanov notation] bar-shaped stacking fault, observed in as-grown 4H-SiC epitaxial layers, are presented. The defect has been identified by means of spatially resolved microphotoluminescence (μ-PL) measurements at different emission wavelengths, focusing on the emission peak at 0.3 eV below the conduction band. Low temperature μ-PL measurements have also been performed. The defect has been identified and characterized using high resolution transmission electron microscopy. Experimental results are correlated and validated by the calculations of the Kohn–Sham electronic band structure and the defect formation energy

Mobile small polaron

Extending the Froehlich polaron problem to a discrete ionic lattice we study a polaronic state with a small radius of the wave function but a large size of the lattice distortion. We calculate the energy dispersion and the effective mass of the polaron with the 1/\lambda perturbation theory and with the exact Monte Carlo method in the nonadiabatic and adiabatic regimes, respectively. The ``small'' Froehlich polaron is found to be lighter than the small Holstein polaron by one or more orders of magnitude.Comment: 4 pages, 4 figures, published versio

Prostate Cancer Pathologic Stage Pt2b (2002 Tnm Staging System): Does It Exist?

Objective: In the 1997 TNM staging system, tumors were classified into a single subdivision: T2a, and bilateral tumor involvement (T2b). In the 2002 TNM staging system, tumors are subclassified as T2a (less than one half of one lobe involvement), T2b (more than one half of one lobe involvement), and T2c (bilateral involvement). A recent study questioned the existence of a true pathologic pT2b tumor. The aim of our study is to verify this question. Materials and methods: The study population consisted of 224 men submitted to radical retropubic prostatectomy. The surgical specimens were histologically evaluated by complete embedding and whole-mount processing. Tumor extent was evaluated by a point-count method. The surgical specimens were staged according to the 2002 TNM staging system. Results: Using the 2002 TNM criteria, the surgical specimens were class ified as pT2a, 28 (12.50%); pT2b, 0 (0%); pT2c, 138 (61.61%); pT3a, 30 (13.39%); and, pT3b, 28 (12.50%). Using the point-count method for tumor extent evaluation, the minimum and maximum total points obtained in unilateral tumors were 192 and 368 points, respectively; the most extensive unilateral tumor showed 68 positive points (less than half the minimum total point-count). Conclusions: Using the point-count method for tumor extent, our study questions a real existence for pathologic stage pT2b tumors (unilateral tumors involving greater than one-half of one lobe).3214347(1997) TNM Classification of Malignant Tumours, pp. 170-173. , International Union Against Cancer (UICC): 5th ed, Sobin LH, Wittekind Ch (ed.), New York, Wiley-Liss(2002) TNM Classification of Malignant Tumours, pp. 184-187. , International Union Against Cancer (UICC): 6th ed, Sobin LH, Wittekind Ch (ed.), New York, Wiley-LissEichelberger, L.E., Cheng, L., Does pT2b cancer exist? Critical appraisal of the 2002 TNM classification of prostate carcinoma (2004) Cancer., 100, pp. 2573-2576Mostofi, F.K., Price Jr., E.B., (1973) Tumors of the Male Genital System, Atlas of Tumor Pathology, pp. 202-217. , Second Series, Fascicle 8. Washington DC, Armed Forces Institute of PathologyGleason, D.F., Mellinger, G.T., Prediction of prognosis for prostatic adenocarcinoma by combined histological grading and clinical staging (1974) J Urol., 111, pp. 58-64Gleason, D.F., Histologic grading of prostate cancer: A perspective (1992) Hum Pathol., 23, pp. 273-279Epstein, J.I., Carmichael, M., Walsh, P.C., Adenocarcinoma of the prostate invading the seminal vesicle: Definition and relation of tumor volume, grade and margins of resection to prognosis (1993) J Urol., 149, pp. 1040-1045Bostwick, D.G., Montironi, R., Evaluating radical prostatectomy specimens: Therapeutic and prognostic importance (1997) Virchows Arch., 430, pp. 1-16Billis, A., Magna, L.A., Ferreira, U., Correlation between tumor extent in radical prostatectomies and preoperative PSA, histological grade, surgical margins, and extraprostatic extension: Application of a new practical method for tumor extent evaluation (2003) Int Braz J Urol., 29, pp. 113-120Billis, A., Freitas, L.L., Magna, L.A., Samara, A.B., Ferreira, U., Prostate cancer with bladder neck involvement: Pathologic findings with application of a new practical method for tumor extent evaluation and recurrence-free survival after radical prostatectomy (2004) Int Urol Nephrol., 36, pp. 363-368Freedland, S.J., Partin, A.W., Epstein, J.I., Walsh, P.C., Biochemical failure after radical prostatectomy in men with pathologic organ-confined disease: pT2a versus pT2b (2004) Cancer, 100, pp. 1646-1649Rubin, M.A., Dash, A., Wei, J.T., Dunn, R., Sanda, M.G., Prostate cancer staging: Recommendations for modifying the 2002 AJCC pathology staging system based on accuracy in reflecting prognosis (2004) Mod Pathol., 17 (SUPPL. 1), pp. 174ACantrell, B.B., DeKlerk, D.P., Eggleston, J.C., Boitnott, J.K., Walsh, P.C., Pathological factors that influence prognosis in stage A prostatic cancer: The influence of extent versus grade (1981) J Urol., 125, pp. 516-520Humphrey, P.A., Vollmer, R.T., Percentage carcinoma as a measure of prostatic tumor size in radical prostatectomy tissues (1997) Mod Pathol., 10, pp. 326-333Renshaw, A.A., Chang, H., D'Amico, A.V., Estimation of tumor volume in radical prostatectomy specimens in routine clinical practice (1997) Am J Clin Pathol., 107, pp. 704-708Renshaw, A.A., Richie, J.P., Loughlin, K.R., Jiroutek, M., Chung, A., D'Amico, A.V., Maximum diameter of prostatic carcinoma is a simple, inexpensive, and independent predictor of prostate-specific antigen failure in radical prostatectomy specimens. Validation in a cohort of 434 patients (1999) Am J Clin Pathol., 111, pp. 641-644Humphrey, P.A., Vollmer, R.T., Intraglandular tumor extent and prognosis in prostatic carcinoma: Application of a grid method to prostatectomy specimens (1990) Hum Pathol., 21, pp. 799-804Carvalhal, G.F., Humphrey, P.A., Thorson, P., Yan, Y., Ramos, C.G., Catalona, W.J., Visual estimate of the percentage of carcinoma is an independent predictor of prostate carcinoma recurrence after radical prostatectomy (2000) Cancer., 89, pp. 1308-131

The boson-fermion model with on-site Coulomb repulsion between fermions

The boson-fermion model, describing a mixture of itinerant electrons hybridizing with tightly bound electron pairs represented as hard-core bosons, is here generalized with the inclusion of a term describing on-site Coulomb repulsion between fermions with opposite spins. Within the general framework of the Dynamical Mean-Field Theory, it is shown that around the symmetric limit of the model this interaction strongly competes with the local boson-fermion exchange mechanism, smoothly driving the system from a pseudogap phase with poor conducting properties to a metallic regime characterized by a substantial reduction of the fermionic density. On the other hand, if one starts from correlated fermions described in terms of the one-band Hubbard model, the introduction in the half-filled insulating phase of a coupling with hard-core bosons leads to the disappearance of the correlation gap, with a consequent smooth crossover to a metallic state.Comment: 7 pages, 6 included figures, to appear in Phys. Rev.

Mass Renormalization in the Su-Schrieffer-Heeger Model

This study of the one dimensional Su-Schrieffer-Heeger model in a weak coupling perturbative regime points out the effective mass behavior as a function of the adiabatic parameter $\omega_{\pi}/J$, $\omega_{\pi}$ is the zone boundary phonon energy and $J$ is the electron band hopping integral. Computation of low order diagrams shows that two phonons scattering processes become appreciable in the intermediate regime in which zone boundary phonons energetically compete with band electrons. Consistently, in the intermediate (and also moderately antiadiabatic) range the relevant mass renormalization signals the onset of a polaronic crossover whereas the electrons are essentially undressed in the fully adiabatic and antiadiabatic systems. The effective mass is roughly twice as much the bare band value in the intermediate regime while an abrupt increase (mainly related to the peculiar 1D dispersion relations) is obtained at $\omega_{\pi}\sim \sqrt{2}J$.Comment: To be published in Phys.Rev.B - 3 figure

Polaron formation for a non-local electron-phonon coupling: A variational wave-function study

We introduce a variational wave-function to study the polaron formation when the electronic transfer integral depends on the relative displacement between nearest-neighbor sites giving rise to a non-local electron-phonon coupling with optical phonon modes. We analyze the ground state properties such as the energy, the electron-lattice correlation function, the phonon number and the spectral weight. Variational results are found in good agreement with analytic weak-coupling perturbative calculations and exact numerical diagonalization of small clusters. We determine the polaronic phase diagram and we find that the tendency towards strong localization is hindered from the pathological sign change of the effective next-nearest-neighbor hopping.Comment: 11 page