679 research outputs found
ANALISA BULLWHIP EFFECT PADA SUPPLY CHAIN CV. ARI TIRTA MANDIRI BOYOLALI
CV Ari Tirta Mandiri merupakan perusahaan yang bergerak dibidang pendistribusian produk AMDK (Air Minum Dalam Kemasan), pendistribusian dilakukan dengan mendistribusikan produknya ke retailer diwilayah pemasaran Boyolali dan Klaten. Dalam melakukan pendistribusian perlu pengurangan
keragaman untuk dapat melakukan pendistrbusian, permasalahan yang dihadapi adalah peningkatan permintaan dari chain hulu ke arah hilir mengukuti arus informasi yang berjalan dalam sistem rantai pasok perusahaan tersebut. Fenomena ini dinamakan Bullwhip Effect yang berpotensi menimbulkan kerugian dalam perusahaan. Salah satu penyebab dari fenomena ini adalah koordinasi yang kurang dari tiap chain dari rantai pasok tersebut. Kesulitan yang paling berpengaruh adalah jumlah permintaan yang selalu berubah ubah yang menjadi tantangan bagi Forecasting untuk selalu menghasilkan peramalan yang paling akurat untuk
menjaga keseimbangan persediaan di tiap-tiap retailnya dengan demand pasar. Untuk mencapai tujuan tersebut digunakan pendekatan Supply Chain Management diawali dengan menghitung semua nilai variabilitas tiap level agregasi pengukuran Bullwhip Effect. Diperoleh identifikasi Bullwhip effect (ω1=1,04653 dan ω3 sebesar 1,067) dimana 1,0083 kemudian dengan mengunakan software QSB 3.0 yang didalamnya untuk terdapat modul peramalan dengan metode Moving Average, Smoothing dan Winter’s Model dilakukan peramalan untuk mendapatkan tingkat permintaan yang digunakan untuk simulasi untuk mengurangi Bullwhip Effect. Tolak ukur dari metode ini adalah nilai eror yang paling kecil dalam hal ini adalah MAD (Mean Absolute Deviation). Peramalan digunakan untuk memperbaiki BW tersebut sehingga
menghasilkan ω1=0,8293 dan ω3 sebesar 0,855 dimana dari 1,0083
Optical Coherence Tomography Angiography of the Optic Disc; an Overview.
Different diseases of the optic disc may be caused by or lead to abnormal vasculature at the optic nerve head. Optical coherence tomography angiography (OCTA) is a novel technology that provides high resolution mapping of the retinal and optic disc vessels. Recent studies have shown the ability of OCTA to visualize vascular abnormalities in different optic neuropathies. In addition, quantified OCTA measurements were found promising for differentiating optic neuropathies from healthy eyes
Making the Mission Computer Intelligent – A Step Ahead
Increasing the complexity of fighter aircraft like modern cockpit environments, covering highly integrated, and complex automatic functions, pose various demands on the crew and adding a heavy workload. Cognitive systems appear to be a promising approach to overcome these deficiencies in future combat aircraft. Developing human-centered automation and designing advanced technology that will capitalize on the relative strengths of humans and machines, are key to the success. This paper presents the approach of applying the artificial intelligence (AI) techniques in the critical mission computer (MC). The mission computer is the central controller of the entire avionics and acts as the front end to the pilot and all other avionic systems by providing all the sensors information, presenting the pilot-vehicle interface and thereby helping a lot in reducing the heavy workload of the pilot. Hence cognitive processing in the MC will make MC to act as an electronic crew assistant sharing the workload of the pilot and helping him in severe situations. Intricate aircraft systems increase the need for intelligent cooperation between pilots and aircraft which will be fulfilled by making the MC as smart or intelligent MC.Defence Science Journal, 2013, 63(2), pp.174-180, DOI:http://dx.doi.org/10.14429/dsj.63.426
Retinal vein occlusion and macular edema – critical evaluation of the clinical value of ranibizumab
Retinal vein occlusions (RVOs) constitute the second most common cause of retinal vascular disease after diabetic retinopathy, with a prevalence of between 1% and 2% in persons older than 40 years of age. Despite the existence of numerous potential therapeutic options, none is entirely satisfactory, and many patients with RVO suffer irreversible visual loss. Fortunately however, the recent introduction of antivascular endothelial growth factor (VEGF) agents, such as ranibizumab (Lucentis®, Genentech, South San Francisco, CA) and bevacizumab (Avastin®, Genentech), offers a potentially new treatment approach for clinicians managing this disorder. The results of the BRAVO and CRUISE trials have provided the first definitive evidence for the efficacy and safety of ranibizumab in the treatment of RVO. As a result, ranibizumab has recently been approved by the US Food and Drug Administration for the treatment of RVO-associated macular edema. In this review, we provide a critical evaluation of clinical trial data for the safety and efficacy of ranibizumab, and address unresolved issues in the management of this disorder
Development of Anti-VEGF Therapies for Intraocular Use: A Guide for Clinicians
Angiogenesis is the process by which new blood vessels form from existing vessel networks. In the past three decades, significant progress has been made in our understanding of angiogenesis; progress driven in large part by the increasing realization that blood vessel growth can promote or facilitate disease. By the early 1990s, it had become clear that the recently discovered “vascular endothelial growth factor” (VEGF) was a powerful mediator of angiogenesis. As a result, several groups targeted this molecule as a potential mediator of retinal ischemia-induced neovascularization in disorders such as diabetic retinopathy and retinal vein occlusion. Around this time, it also became clear that increased intraocular VEGF production was not limited to ischemic retinal diseases but was also a feature of choroidal vascular diseases such as neovascular age-related macular degeneration (AMD). Thus, a new therapeutic era emerged, utilizing VEGF blockade for the management of chorioretinal diseases characterized by vascular hyperpermeability and/or neovascularization. In this review, we provide a guide for clinicians on the development of anti-VEGF therapies for intraocular use
Choriocapillaris flow impairment predicts the development and enlargement of drusen
Purpose: To evaluate the choriocapillaris flow in regions of enlarged or new incident drusen in patients with early and intermediate age-related macular degeneration (AMD). Methods: We retrospectively reviewed and analyzed structural optical coherence tomography (OCT) and OCT angiography (OCTA) images of consecutive patients with early or intermediate AMD evaluated at the Doheny-UCLA Eye Centers between 2015 and 2018. All patients were imaged using a Cirrus OCT, and only one eye was included in the study. To be eligible for this analysis, patients were required to have a 3
7 3-mm OCTA scan acquired during the first visit (considered as baseline) and a fovea-centered 512
7 128 macular cube (6
7 6 mm) acquired at both the baseline visit and after a minimum of 1 year follow-up. The drusen maps generated from the macular cubes were used to generate a drusen area (DA) measurement and compute the difference between baseline and follow-up (\u394DA). After registering the structural OCTs to the baseline choriocapillaris (CC) OCTA, we analyzed and compared the baseline flow deficits (FD) within drusen-free region (FDDF), regions into which drusen enlarged or expanded at follow-up (FDEN), and regions in which new incident drusen (FDND) appeared at follow-up. Results: Forty-six patients were eligible for the analysis and had a mean follow-up of 1.47 years. Twelve eyes of 12 subjects had a \u394DA < 0.1 mm2. In these eyes, only the FDDF was calculated (40.37 \ub1 2.29%) and it was not significantly different from the FDDF of eyes with \u394DA 65 0.1 mm2 (40.25 \ub1 4.37%, p = 0.849). When comparing the different regions within the eyes with \u394DA 65 0.1 mm2, there was no significant difference between FDED and FDND (43.61 \ub1 4.36% and 44.16 \ub1 2.38%, p = 528), but both were significantly higher than FDDF (p = 0.001 and p < 0.001, respectively). Conclusions: Significant CC flow impairment is present under regions of intact retinal pigment epithelium (RPE) where existing drusen will enlarge into or new drusen will appear within 2 years. These findings suggest that location of drusen may not be stochastic but may be driven by regional deficits in the choriocapillaris
Ultra-Widefield Indocyanine Green Angiography Reveals Patterns of Choroidal Venous Insufficiency Influencing Pachychoroid Disease
PURPOSE. To compare patterns of choroidal venous drainage in eyes with pachychoroid disease to those of healthy subjects using ultra-widefield indocyanine green angiography (UWF ICGA). METHODS. Patients with pachychoroid disease and healthy controls were recruited at two referral centers. UWF ICGA images were used to evaluate the proportion of the postequatorial fundus drained by major vortex vein systems in each quadrant and to study the incidence and topography of choroidal vascular hyperpermeability (CVH) and intervortex venous anastomoses.Widefield swept-source optical coherence tomography (SS-OCT) was used to evaluate choroidal thickness at the posterior pole in eyes with pachychoroid disease. RESULTS. Fifty-two pachychoroid eyes and 26 healthy eyes were evaluated. Eyes with pachychoroid disease showed a significant within-subject variance in the proportion of the postequatorial fundus drained by each vortex vein system (range, 4.1%-48.1%; P < 0.0001) that was not seen in controls (range, 17.3%-31.7%; P = 0.11). CVH was present in all pachychoroid disease eyes and three of 26 controls. Intervortex venous anastomoses were present in 46 of 52 pachychoroid disease eyes and nine of 26 control eyes. Vortex vein systems with large drainage areas showed greater density of CVH spots. SSOCT demonstrated asymmetric choroidal drainage in the macula of 59% of pachychoroid eyes. CVH and intervortex venous anastomoses were more prominent in areas showing maximal choroidal thickness. CONCLUSIONS. In eyes with pachychoroid disease, imbalanced choroidal venous drainage with congestion of specific vortex vein systems may contribute to a state of choroidal venous insufficiency characterized by regional choroidal thickening, CVH and remodeling of venous drainage routes. © 2022 The Authors
Alterations in the Choriocapillaris in Intermediate Age-Related Macular Degeneration.
Purpose The purpose of this study was to compare the choriocapillaris plexus in eyes with intermediate AMD (iAMD), with or without neovascular AMD in the fellow eye, using optical coherence tomography angiography (OCTA). Methods We collected data from 42 eyes with iAMD from 42 patients who had obtained OCTA. This cohort was divided into two subgroups according to the status of the fellow eye, yielding a group of 20 cases with bilateral intermediate AMD (bilateral iAMD group) and 22 cases with neovascular AMD in the fellow eye (unilateral iAMD group). An additional control group of 20 eyes from 20 healthy subjects was included for comparison. Main outcome measures were: (1) the percent of nondetectable perfused choriocapillaris area and (2) the average choriocapillaris signal void size. Results No differences in the percent of nondetectable perfused choriocapillaris area were found among the three groups (2.3 ± 1.4% in the unilateral iAMD group, 1.5 ± 0.9% in the bilateral iAMD group, and 1.7 ± 1.4% in the control group, respectively). The average choriocapillaris signal void size, however, was significantly increased in unilateral iAMD eyes (293.7 ± 71.2 μm2) compared to both bilateral iAMD (241.5 ± 51.6 μm2, P = 0.031) and control (212.7 ± 48.6 μm2, P = 0.001) eyes. Conclusions Intermediate AMD eyes of patients with neovascular AMD in the fellow eye have an increased average choriocapillaris signal void size compared to eyes without neovascular AMD in the fellow eye. If replicated in future studies, choriocapillaris signal void size may prove to be a useful parameter for evaluating eyes with AMD
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