Sercan Külcü

Sercan Külcü

Assistant Professor, Computer Engineering, Giresun University

Blog Posts

Epic Games Challenges Mobile App Store Policies

4 minute read

Published:

On August 13, 2020, Epic Games updated Fortnite — one of the world’s most widely played games, with approximately 350 million registered accounts — to offer a direct payment option that bypassed Apple’s in-app purchase system. Epic’s “Epic Direct Payment” offered Fortnite’s in-game currency (V-Bucks) at a 20 percent discount compared to the price charged through Apple’s IAP system ($7.99 versus $9.99 for 1,000 V-Bucks), where Apple’s 30 percent commission had been built into the price. Apple’s App Store Review Guidelines required all digital content purchases in iOS apps to use Apple’s in-app purchase system, with Apple receiving 30 percent (15 percent for subscriptions after the first year, for developers earning under $1M through Apple’s Small Business Program). Apple removed Fortnite from the App Store within hours of detecting the policy violation; Google removed it from Google Play the same day (though Fortnite had already been available via direct download/sideload on Android). Epic had prepared for the removal: simultaneously with the update, Epic filed a lawsuit against Apple in the US District Court for the Northern District of California, and a separate lawsuit against Google, both alleging antitrust violations. Epic also published a parody video titled “Nineteen Eighty-Fortnite” — a direct parody of Apple’s famous “1984” Super Bowl advertisement — with Fortnite characters fighting an “Apple Corporation” controlling citizens, reversing the iconic imagery to cast Apple as the monopoly rather than the liberator. Read more

GPT-3 Demonstrates the Scale of Large Language Models

4 minute read

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OpenAI published the GPT-3 paper (“Language Models are Few-Shot Learners”) on arXiv May 28, 2020, and opened a private API beta in June 2020. The model contained 175 billion parameters — 117 times larger than GPT-2’s 1.5 billion — trained on approximately 300 billion tokens drawn from a filtered version of Common Crawl (60%), WebText2 (the web corpus from GPT-2, 22%), two book datasets (16%), and English Wikipedia (3%). The transformer architecture used 96 layers, 96 attention heads, and 12,288-dimensional embeddings, requiring approximately 800 GB to store in 16-bit floating-point precision. Estimated training cost was roughly $4.6 million at then-current V100 cloud GPU prices, requiring several thousand GPUs for months. Read more

The Gaming PC I Would Build in 2020

3 minute read

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If I were building a gaming PC on July 1, 2020, this is the machine I would actually want. I am not simply choosing the most expensive part in every category. The priority is gaming performance, then reliability, cooling and enough headroom to keep the system useful for years. Read more

Apple Announces the Move From Intel to Apple Silicon

2 minute read

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Apple announced at WWDC 2020 (June 22, 2020) that Macs would transition from Intel x86-64 processors to Apple-designed ARM-based silicon over a two-year period — the Mac’s third major CPU architecture change after Motorola 68k to PowerPC (1994) and PowerPC to Intel (2005–2006). Apple CEO Tim Cook announced the transition alongside a Developer Transition Kit (a Mac mini with the A12Z Bionic chip from the iPad Pro, loaned to registered developers for $500) to allow software porting before consumer hardware arrived. Apple emphasized two compatibility layers: Universal 2 binaries (a fat binary format containing both ARM64 and x86-64 code in one application package, allowing one download to run natively on both architectures) and Rosetta 2 (a successor to the original Rosetta used during the PowerPC-to-Intel transition, now performing ahead-of-time translation of x86-64 code to ARM64 at app install time rather than interpreting at runtime, giving dramatically faster performance than runtime JIT translation). Virtualization of ARM Linux and Windows for ARM was also supported. Read more

Software Bug Of Therac-25

4 minute read

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The Therac-25 is one of the most studied cases in software-engineering history because the consequences of the bugs it contained were not degraded performance or corrupted data. Patients received radiation doses hundreds of times above therapeutic levels. At least six people were seriously injured. Three died. Read more

Software Bug Of Pathfinder

4 minute read

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Mars Pathfinder landed successfully on July 4, 1997 — the first Mars lander since the Viking missions of 1976. The entry, descent, and landing were flawless. Within days, the spacecraft and its small rover Sojourner were returning data and images. Then the resets began. Read more

Microsoft Releases Windows Terminal 1.0

3 minute read

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Microsoft released Windows Terminal 1.0 in May 2020, roughly a year after its first public preview at Microsoft Build 2019. The application replaced decades-old infrastructure: Command Prompt ran on conhost.exe, a host that dated to Windows NT and had no support for modern text rendering, multiple tabs, or proper Unicode. Read more

Apple and Google Announce Exposure Notification Technology

3 minute read

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Apple and Google announced the Exposure Notification API on April 10, 2020, seventeen days after the World Health Organization declared COVID-19 a pandemic, in an unprecedented collaboration between the two companies whose competing mobile operating systems controlled over 99 percent of the global smartphone market. The announcement came as governments worldwide were evaluating contact-tracing applications that varied widely in their privacy properties — Singapore’s TraceTogether (March 20, 2020) used a centralized Bluetooth proximity log architecture where the health ministry held contact graphs, raising concerns about government surveillance. Several European countries were building centralized systems as well. The Apple-Google design deliberately chose a decentralized architecture: each phone generated a daily Temporary Exposure Key (TEK) using a cryptographically secure random source, then derived short-lived Rolling Proximity Identifiers (RPIs) from the TEK every 10-20 minutes using HMAC-SHA256. Phones broadcast their current RPI over Bluetooth Low Energy advertising packets while simultaneously logging the RPIs they observed from nearby devices, along with signal strength (RSSI) as a proxy for distance. No names, phone numbers, GPS locations, or account identifiers were broadcast or logged — only the cryptographic identifiers, which were unlinkable to individuals without knowledge of the originating TEK. Read more

Remote Work Tools Become Critical Infrastructure

3 minute read

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The World Health Organization declared COVID-19 a pandemic on March 11, 2020, and within days, shelter-in-place orders in major cities (San Francisco Bay Area March 16, New York City March 22) forced millions of knowledge workers, students, and teachers to begin working and learning from home simultaneously. The speed and scale of the transition placed unprecedented demand on digital collaboration infrastructure. Zoom Video Communications had approximately 10 million daily meeting participants in December 2019; by April 2020 that figure had reached 300 million — a 30× increase in four months — representing a growth trajectory that would normally take 5-7 years at expected rates. Zoom’s architecture (WebRTC-based media with their own media encoding, meeting rooms hosted on Zoom’s servers) had to scale media processing, recording storage, and global anycast network routing in weeks rather than years. Microsoft Teams grew from 32 million daily active users in March 2020 to 75 million in April 2020. Slack, which had been primarily a text-based channel tool, saw concurrent user counts surge to 12.5 million. These platforms faced not only scale challenges but reliability requirements that consumer-grade services had never faced: a dropped video call in a business meeting, a school lesson that couldn’t connect, or a hospital telemedicine consultation that failed had real costs that casual use did not. Read more

Samsung Unveils the Galaxy Z Flip

3 minute read

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Samsung unveiled the Galaxy Z Flip at Samsung Unpacked on February 11, 2020, pricing it at $1,380 — significantly less than the Galaxy Fold ($1,980) and Motorola Razr 2019 ($1,499), its direct competitors in the emerging foldable clamshell category. The Z Flip’s 6.7-inch Infinity Flex Dynamic AMOLED display folded vertically to a compact 73.6×87.4 mm square, compared to the Motorola Razr’s similar form factor. The critical materials difference was Samsung’s use of Ultra-Thin Glass (UTG) — approximately 30 μm thick glass from Schott AG with a polymer backing — as the display substrate, replacing the plastic film (polyimide) used in the Galaxy Fold and Motorola Razr. The UTG provided a harder surface that resisted fingernail scratching and felt more like traditional glass to the touch, though it was still flexible enough to fold. A 1.1-inch 300×116 pixel cover display showed time, notifications, and music controls when closed. The SoC was the Snapdragon 855+ (not the then-current Snapdragon 865), with 8 GB RAM and 256 GB UFS 3.0 storage, running Android 10 with One UI 2.1. Read more

The Story Of Computing

4 minute read

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The story of computing is also a story about human limits. For thousands of years, people have built tools to extend what the mind alone can do — to count faster, to record more, to calculate at scales impossible by hand. An abacus, a mechanical calculator, a punched card, and a modern processor look completely different but serve the same basic impulse: move some mental work outside the human mind. Read more

Microsoft Ends Support for Windows 7

3 minute read

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Microsoft ended extended support for Windows 7 on January 14, 2020 — a milestone that the company had announced and counted down for years. Windows 7 had shipped October 22, 2009, giving it a 10-year-3-month support lifecycle: mainstream support ended January 13, 2015 (after which no new features or non-security fixes were added), and extended support (security patches only) ran for five additional years until January 14, 2020. At end-of-life, Windows 7 still accounted for approximately 26–33% of all active Windows PCs globally depending on the survey methodology — tens of millions of machines ranging from home desktops to industrial controllers to hospital workstations — making it one of the largest simultaneous end-of-support events in consumer software history. The healthcare sector illustrated the most severe risks: WannaCry (May 12, 2017) had spread via the EternalBlue exploit (a leaked NSA tool targeting the SMBv1 protocol), affecting over 300,000 computers running Windows 7 and Windows XP across 150 countries, shutting down approximately one-third of NHS England trusts and forcing cancellation of 19,000 medical appointments. The SMB vulnerability had been patched (MS17-010, March 14, 2017) but hospitals running Windows 7 systems hadn’t applied the patch due to lengthy medical device recertification cycles. Read more

Wi-Fi 6 Hardware Becomes Widely Available

2 minute read

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The Wi-Fi Alliance certified the 802.11ax standard as “Wi-Fi 6” in September 2019, after three years of IEEE standardization work beginning with the 802.11ax task group formation in 2014. The standard’s peak theoretical throughput reached 9.6 Gbps (vs 3.5 Gbps for Wi-Fi 5/802.11ac) using a combination of 1024-QAM modulation (25% more data per symbol than Wi-Fi 5’s 256-QAM) and wider 160 MHz channels, but the more consequential improvements were in multi-device efficiency. Intel shipped the Wi-Fi 6-certified AX200 M.2 adapter in July 2019 (the first mainstream PC Wi-Fi 6 card), Samsung’s Galaxy S10 (March 2019) was the first Wi-Fi 6-certified smartphone, and Apple’s iPhone 11 (September 2019) added Wi-Fi 6 — establishing it in flagship hardware before Christmas 2019. Router availability was wider: the Netgear Nighthawk AX12 (RAX200) launched at ~$500, Asus ROG Rapture GT-AX11000 at ~$450, and TP-Link Archer AX6000 at ~$300, all in 2019. Read more

GitHub Announces Actions for General Availability

3 minute read

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GitHub Actions reached general availability on November 13, 2019, extending a beta period that began in August 2018. The feature added a built-in CI/CD system to GitHub repositories, letting developers define automated workflows in YAML files stored at .github/workflows/. A workflow specified triggers (push to a branch, pull request opened, release created, scheduled cron, or manual dispatch), jobs (each running in an isolated virtual machine), and steps (shell commands or reusable “actions” from the GitHub Marketplace). GitHub provided hosted runners on Ubuntu (2-core, 7GB RAM), Windows, and macOS at no cost for public repositories, with paid minutes for private repositories starting at $0.008 per minute for Linux. Read more

Google Claims Quantum Supremacy With Sycamore

4 minute read

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Google published a paper in Nature on October 23, 2019 claiming that its 53-qubit Sycamore processor had achieved “quantum supremacy” — completing a specific computational task that would take the world’s fastest classical supercomputers an astronomically long time to match. The paper had leaked two days early when a draft appeared on NASA’s website (NASA collaborates with Google on quantum computing research) on September 20, 2019, generating widespread coverage before the official publication. The task chosen was Random Circuit Sampling (RCS): apply a random sequence of quantum logic gates to the 53 qubits (one of Sycamore’s 54 qubits was non-functional), then measure all qubits to obtain a 53-bit output string. Repeat this millions of times. The output distribution of a random quantum circuit is theoretically very hard to classically simulate because the quantum state evolves through a superposition of 2^53 (approximately 9 quadrillion) simultaneous values during the computation. Google estimated that the Summit supercomputer at Oak Ridge National Laboratory — the world’s fastest at 200 petaflops at the time — would require approximately 10,000 years to sample from the same distribution that Sycamore sampled in 200 seconds. Sycamore operated at approximately 15 millikelvin (colder than the cosmic microwave background at ~2.7 K) using superconducting transmon qubits, achieving a two-qubit gate error rate of approximately 0.6 percent and a single-qubit gate error rate below 0.1 percent — among the lowest error rates achieved in a superconducting quantum processor at that scale. Read more

Welcome to Our Department

1 minute read

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If you are starting Computer Engineering in 2019, you are entering a discipline that touches almost every industry. Read more

Apple Introduces the A13 Bionic

3 minute read

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Apple introduced the A13 Bionic with the iPhone 11, 11 Pro, and 11 Pro Max in September 2019. The chip used TSMC’s second-generation 7nm process (N7P) with around 8.5 billion transistors, up from 6.9 billion in the A12. Two high-performance CPU cores were rated at 20% faster than the A12’s, and four efficiency cores used 40% less power for the same workload. Read more

Why Choose Computer Engineering in 2019?

3 minute read

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In 2019, software is becoming an invisible layer inside almost everything we use. Phones, vehicles, payment systems, factories, streaming services, medical devices, and public infrastructure all depend on computing. Studying Computer Engineering means learning how this layer is designed. Read more