Pengaruh Pemberian Momentum Pada Artificial Neural Network Backpropagation

Salah satu algoritma Artificial Neural Network (ANN) yang biasa digunakan adalah algoritmabackpropagation dengan pola model gradient descent pada proses pembelajarannya. Akan tetapi,gradient descent memiliki kelemahan yaitu tidak mudah digunakan dan terkadang lambat dalampengkonvergenan solusinya. Untuk mengatasi kelemahan tersebut dilakukan suatu modifikasi yaitudengan memberikan momentum pada Perubahan bobotnya. Pada proses prediksi surface roughnesspada CNC Milling menggunakan ANN Backpropagation dengan momentum pada Perubahan bobotini, nilai rata-rata persentase error yang dihasilkan pada masing-masing nilai momentum yangdiberikan adalah tidak banyak mengalami Perubahan. Namun jika nilai momentum yang diberikanmendekati nilai maksimal momentum yaitu mendekati nilai satu maka akan menyebabkanterjadinya overshoot. Pemberian momentum pada Perubahan bobot menyebabkan Perubahan yangcukup besar yaitu pada waktu prosesnya, semakin besar nilai momentum yang diberikan makasemakin cepat pula waktu proses yang dibutuhkan. Hal ini berarti jika ingin waktu prosesprediksinya menjadi cepat maka gunakan nilai momentum yang besar, namun sebaiknya kurangdari 0.9

Anterior and Posterior Corneal Astigmatism after Refractive Lenticule Extraction for Myopic Astigmatism

Purpose. To assess the amount and the axis orientation of anterior and posterior corneal astigmatism after refractive lenticule extraction (ReLEx) for myopic astigmatism. Methods. We retrospectively examined 53 eyes of 53 consecutive patients (mean age ± standard deviation, 33.2 ± 6.5 years) undergoing ReLEx to correct myopic astigmatism (manifest cylinder = 0.5 diopters (D)). Power vector analysis was performed with anterior and posterior corneal astigmatism measured with a rotating Scheimpflug system (Pentacam HR, Oculus) and refractive astigmatism preoperatively and 3 months postoperatively. Results. Anterior corneal astigmatism was significantly decreased, measuring 1.42 ± 0.73 diopters (D) preoperatively and 1.11 ± 0.53 D postoperatively (p<0.001, Wilcoxon signed-rank test). Posterior corneal astigmatism showed no significant change, falling from 0.44 ± 0.12 D preoperatively to 0.42 ± 0.13 D postoperatively (p=0.18). Refractive astigmatism decreased significantly, from 0.92 ± 0.51 D preoperatively to 0.27 ± 0.44 D postoperatively (p<0.001). The anterior surface showed with-the-rule astigmatism in 51 eyes (96%) preoperatively and 48 eyes (91%) postoperatively. By contrast, the posterior surface showed against-the-rule astigmatism in all eyes preoperatively and postoperatively. Conclusions. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after ReLEx for myopic astigmatism

The Taman Siswa in Postwar Indonesia

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コウトウ キョウイク カイカク ノ ソウゴ コウイ ブンセキ : ビデオ エスノグラフィー ケンキュウ ノ ネライ ト コウガクブ トシ コウガク エンシュウ ノ ジッサイ

ビデオエスノグラフィーは、当事者的知識を十分に摂取しながら行うビデオ分析であり、我々は この方法で、高等教育改革の現場を研究した。生涯学習社会の到来を受けて、日本の高等教育は現在第 2 次世界大戦直後以来の改革期にある。すなわち、「知識」より「生涯学習能力」の獲得を志向した、 自発性を尊重するような様々な取り組みがなされ始めている。この高等教育の現場に対し、ワークプレ ース研究を行った。Ｂ大学工学部都市工学演習α班を分析対象とした調査の結果、①演習の課題解釈に は「従来の指標の相対化の要求の程度」を巡って２つの解釈があり得たこと、②班内にはその２種類の 解釈に対応した葛藤・対立的相互行為が存在したこと、③にもかかわらず、班内葛藤を生きる当事者が ともに専門性（「都市工学」）を志向していたこと、④したがって、課題理解のいかんにかかわらず、 班活動の全体が「都市工学演習」と呼び得るものになっていたこと、⑤その一方で、最終審査会場（ジ ュリー）ではこの２重性が十分レリバントなものとして浮かび上がって来ていなかったこと、これらの ことがわかった。諸結果を総合すると、学生の自主的活動を尊重するタイプの、新しい学習方法の吟味・ 評価のためには、学生によるその方法の実践状況の分析が有意義であるだろうこと、また、それは、場 合によっては教員の評価のパラダイムを変える力を持つだろうことなどが予測された。なお、本報告は、 文科省科学研究費補助金「高等教育改革のコミュニケーション分析－現場における文化変容の質的検討 －」（基盤研究（Ｂ）、 課題番号 １８３３０１０５、研究代表者：樫田美雄）ほかによる研究成果 の一部である

Assessment of low-vault cases with an implantable collamer lens.

This study aimed to examine clinical results in low-vault eyes after implementation of a Hole implantable collamer lens (KS-AquaPORT™, STAAR Surgical Company) in terms of visual outcomes and complications over a one-year follow-up period. This was a retrospective cohort study of subjects who underwent Hole implantable collamer lens surgery at Sanno Hospital, exhibited low vault, and were followed up for 1 year. Patients were included if they met the following criteria: 20≤ age ≤55 years; stable refraction ≥6 months; -1.0 to -20.0 diopters of myopia; endothelial cell density ≥1800 cells/mm2; and no history of ocular surgery, progressive corneal degeneration, cataract, glaucoma, or uveitis. Main outcome measurements were the safety and efficacy indices, predictability, and vault. Values were indicated as the mean ± standard deviation. Subjects included 16 patients (age: 38 ± 8 years; 6 males; 25 eyes). Toric lenses were utilized for 10 eyes. Implantable collamer lens size was 12.1, 12.6, and 13.2 mm for 18, 6, and 1 eye(s), respectively. One year postoperatively, the safety index was 1.07; for 22 eyes with a target refraction of that of emmetropic eyes, the efficacy index was 0.90; and 96% of eyes were within ± 0.50 diopters of attempted versus achieved spherical equivalent correction. Postoperative vault was 142 ± 60 μm. One year postoperatively, no additional surgery was required for rotation of toric implantable collamer lens, and no advanced cataracts, increased intraocular pressure, or decreased endothelial cells were observed. In conclusion, Hole implantable collamer lens yielded satisfactory visual outcomes and no postoperative complications for low-vault eyes, suggesting its suitability for such cases

Time course of optical quality and intraocular scattering after refractive lenticule extraction.

PURPOSE: To assess the time course of optical quality and intraocular scattering in relation to visual acuity after femtosecond lenticule extraction (FLEx) for the correction of myopia. METHODS: This study evaluated 36 eyes of 36 patients with spherical equivalents of -4.38±1.53 D [mean ± standard deviation] who underwent FLEx. Before surgery, and 1 week and 1, 3 and 6 months after surgery, we assessed the modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scattering index (OSI), and OQAS values (OVs), using a double-pass instrument. We also investigated the relationship of the OSI with corrected distance visual acuity (CDVA) preoperatively and postoperatively. RESULTS: The mean changes in MTF cutoff frequency, Strehl ratio, OSI, OV100%, OV20%, and OV9% preoperatively and 6 months postoperatively were -5.51 ± 15.01, -0.03 ± 0.07, 0.35 ± 0.83, -0.17 ± 0.48, -0.14 ± 0.38, and -0.09 ± 0.22, respectively. We found no significant preoperative correlation between the OSI and logMAR CDVA (Spearman rank correlation coefficient r = 0.068, p = 0.69), and modest, but significant correlations 1 week and 1, 3, and 6 months postoperatively (r = 0.572, r = 0.562, r = 0.542, r = 0.540, p<0.001, respectively). CONCLUSIONS: FLEx induced a transient decrease in optical quality in association with an increase in intraocular scattering in the early postoperative period, possibly due to mild interface haze formation, but gradually recovered with time. It is suggested that this transient degradation in optical quality related to an increase in the intraocular scattering may result in a slight delay of CDVA recovery in the early postoperative period

Clinical outcomes of penetrating keratoplasty performed with the VisuMax femtosecond laser system and comparison with conventional penetrating keratoplasty.

To assess the clinical outcomes of femtosecond laser-assisted keratoplasty (FLAK) using the VisuMax femtosecond laser system, and to compare them with those of conventional penetrating keratoplasty (PK).We retrospectively examined 20 eyes of 20 consecutive patients undergoing FLAK and 20 eyes of 20 age- and diagnosis-matched patients undergoing conventional PK. We quantitatively assessed corneal astigmatism, refractive astigmatism, and corrected visual acuity, 1, 3, and 6 months postoperatively, and endothelial cell density 6 months postoperatively.Corneal and refractive astigmatism after FLAK were significantly lower after FLAK than that after conventional PK at 3 and 6 months postoperatively (p = 0.04 and p = 0.03, respectively, Mann-Whitney U test). FLAK provided significantly faster visual recovery than conventional PK at 1 month postoperatively (p = 0.02), but not at 3 and 6 months postoperatively (p = 0.52 and p = 0.80, respectively). We found no significant differences in the change in endothelial cell density between the two groups (p = 0.30).FLAK using the VisuMax femtosecond laser system induces significantly less corneal and refractive astigmatism than conventional PK, and provides significantly faster visual recovery in the early postoperative period, possibly because the geometry of the donor-recipient matching is more physiological and requires less tight sutures. It is suggested that FLAK has advantages over conventional PK, in terms of astigmatism and fast visual recovery

Longitudinal assessment of optical quality and intraocular scattering using the double-pass instrument in normal eyes and eyes with short tear breakup time.

PURPOSE: To assess the longitudinal changes in optical quality including intraocular scattering in normal eyes and eyes with short tear breakup time (TBUT). METHODS: We prospectively examined twenty eyes of 20 healthy subjects, and age-matched twenty eyes of 20 short TBUT subjects. The modulation transfer function (MTF) cutoff frequency, the Strehl ratio, and the objective scattering index (OSI) were quantitatively assessed using an Optical Quality Analysis System. We investigated the changes in these variables measured consecutively at the initial examination, 5, and 10 seconds without blinking. We also compared these variables in eyes with short TBUT with those in normal eyes. RESULTS: No significant differences in the MTF cutoff frequency, Strehl ratio, or OSI were detected over a 10-second period in normal eyes. These variables also became significantly degraded even over a 5-second period in eyes with short TBUT (p<0.01). We found significant differences in these variables at 5 and 10 seconds (p<0.05), but none immediately after the blink between normal and short TBUT eyes. CONCLUSIONS: Optical quality including intraocular scattering deteriorated significantly with time in eyes with short TBUT, whereas we found significant differences over a 10-second period in normal eyes. Eyes with short TBUT showed greater deterioration in optical quality after the blink than normal eyes. The longitudinal assessment of optical quality may be effective in distinguishing eyes with short TBUT from normal eyes

Three-year follow-up of posterior chamber toric phakic intraocular lens implantation for moderate to high myopic astigmatism.

PURPOSE: To assess the 3-year clinical outcomes of toric phakic intraocular lens (Visian ICL™; STAAR Surgical) implantation for moderate to high myopic astigmatism. METHODS: This retrospective study evaluated fifty eyes of 28 patients who underwent toric ICL implantation for the correction of moderate to high myopic astigmatism and who regularly returned for postoperative examination. Before, and 1, 3, and 6 months after, and 1, 2, and 3 years after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery in eyes undergoing toric ICL implantation. RESULTS: The logarithm of the minimal angle of resolution (LogMAR) uncorrected visual acuity and LogMAR best spectacle-corrected visual acuity were -0.10 (corresponding to Snellen equivalents 20/16) ± 0.16 and -0.20 (corresponding to 20/12.5) ± 0.07, 3 years postoperatively, respectively. The safety and efficacy indices were 1.16 ± 0.20 and 0.94 ± 0.28. At 3 year, 82% and 98% of the eyes were within 0.5 and 1.0 D, respectively, of the targeted correction. Manifest refraction changes of -0.15 ± 0.31 D occurred from 1 month to 3 year. No vision-threatening complications occurred during the observation period. CONCLUSIONS: On the basis of the clinical results of this study, toric ICL implantation was good in all measures of safety, efficacy, predictability, and stability for the correction of moderate to high myopic astigmatism throughout a 3-year observation period