正在加载视频...

视频加载失败

加载此视频时出现问题。这可能是由于临时网络问题，或视频可能不可用。

Pitch clock: 15 seconds ⏱️ Jack Dreyer solves a Rubik’s Cube in 13 😮‍💨🧩 Spring Training content idea? 👀⚾️

SportsNet LA

173,028 subscribers

19,489 次观看 • 5 个月前 •via X (Twitter)

Anya Rossi• Live Now

Private livecam show

0 条评论

暂无评论

原始帖子的评论将显示在这里

相关视频

Completing a Rubik’s Cube in 3 seconds is WILD AF. 👀

Completing a Rubik’s Cube in 3 seconds is WILD AF. 👀

American AF 🇺🇸

14,736 次观看 • 3 个月前

Pitcher Jack Dreyer, who was promoted to the Dodger 40-man roster in November, can solve a Rubik’s Cube fast. How fast? Check it out.

Pitcher Jack Dreyer, who was promoted to the Dodger 40-man roster in November, can solve a Rubik’s Cube fast. How fast? Check it out.

Dodger Insider

20,688 次观看 • 1 年前

🚨A 5-year-old girl from China shocks viewers after solving a Rubik’s Cube in just 15 seconds.

🚨A 5-year-old girl from China shocks viewers after solving a Rubik’s Cube in just 15 seconds.

RussiaNews 🇷🇺

328,398 次观看 • 2 个月前

.Noah Clowney vs. the Rubik’s Cube — can he solve it in under a minute tho? 👀🧩 Don’t miss the latest Nets Pod, presented by Ticketmaster, with sarah kustok →

.Noah Clowney vs. the Rubik’s Cube — can he solve it in under a minute tho? 👀🧩 Don’t miss the latest Nets Pod, presented by Ticketmaster, with sarah kustok →

Brooklyn Nets

30,536 次观看 • 7 个月前

"I will never challenge a pitch." -Chris Sale "We'll go over it with the analytics team." -Sean Murphy "I heard because I'm short it's going to help me." -Ozzie Albies ⚾️⚾️⚾️ MLB's new ABS Challenge System has been a hot topic in the #Braves Spring Training clubhouse ⬇️

"I will never challenge a pitch." -Chris Sale "We'll go over it with the analytics team." -Sean Murphy "I heard because I'm short it's going to help me." -Ozzie Albies ⚾️⚾️⚾️ MLB's new ABS Challenge System has been a hot topic in the #Braves Spring Training clubhouse ⬇️

Justin Felder

22,072 次观看 • 4 个月前

The Phillies will have to make a decision on OF Bryan De La Cruz soon due to a July opt-out in his minor league contract. (reported by Jim Salisbury in Spring Training) De La Cruz had a pretty good June in AAA: 78 AB | 26 H | 4 HR | 15 RBI | 13 BB 15 K | .333/.429/.551

The Phillies will have to make a decision on OF Bryan De La Cruz soon due to a July opt-out in his minor league contract. (reported by Jim Salisbury in Spring Training) De La Cruz had a pretty good June in AAA: 78 AB | 26 H | 4 HR | 15 RBI | 13 BB 15 K | .333/.429/.551

Phillies Tailgate

25,977 次观看 • 12 天前

FINAL: Canisius 51, St. Joe's 49 Down goes #1 Nicholas Purdie delivers the game-winning 3-pointer from the corner with 3 seconds left!! See video below… He finishes with a game-high 15 pts for the Crusaders and we have a new #1 in WNY Jack Cullinan nets 10 pts, 5 of them coming late and crucial ones. Patrick Cullinan & Jahyden Clark also finish in double figures Nate Blenman & Mekhi Gidney lead three Marauders 13 pts each

FINAL: Canisius 51, St. Joe's 49 Down goes #1 Nicholas Purdie delivers the game-winning 3-pointer from the corner with 3 seconds left!! See video below… He finishes with a game-high 15 pts for the Crusaders and we have a new #1 in WNY Jack Cullinan nets 10 pts, 5 of them coming late and crucial ones. Patrick Cullinan & Jahyden Clark also finish in double figures Nate Blenman & Mekhi Gidney lead three Marauders 13 pts each

🏀centercourt🏀

17,632 次观看 • 1 年前

Thomas Frank and his staff have taken the 1K Test to Tottenham. It’s essentially a time trial over 1000m (10 lengths of a full pitch), up and back as fast as you can. The idea is that your MAS (maximal aerobic speed) is then calculated by 1000 ÷ time in seconds (e.g., 3:10 = 1000 ÷ 190 = 5.26 m/s). Pro players will generally look to hit between 3mins 20 and 3mins 40 seconds. As you can hear on the clip on the next slide, Dom Solanke managed 3min 28secs, which would give him a MAS of 4.8 m/s. By the end of preseason, Spurs would test the players again and look to improve their MAS scores with targeted training interventions.

Thomas Frank and his staff have taken the 1K Test to Tottenham. It’s essentially a time trial over 1000m (10 lengths of a full pitch), up and back as fast as you can. The idea is that your MAS (maximal aerobic speed) is then calculated by 1000 ÷ time in seconds (e.g., 3:10 = 1000 ÷ 190 = 5.26 m/s). Pro players will generally look to hit between 3mins 20 and 3mins 40 seconds. As you can hear on the clip on the next slide, Dom Solanke managed 3min 28secs, which would give him a MAS of 4.8 m/s. By the end of preseason, Spurs would test the players again and look to improve their MAS scores with targeted training interventions.

STATSports

74,381 次观看 • 1 年前

This week on Divot I interviewed James Dumoulin from The School of Hard Knocks why 3 seconds decides everything in going viral, turning rejection into fuel, how he's interviewed 50 billionaires at only 23, and how he is building his media empire on billions of views one clip at a time. Timestamps: 01:48 — How School of Hard Knocks Started 03:56 — 400 Posts With Only 50 Followers 04:41 — From $100K Months to $1M Months 06:15 — How Small Teams Can Win With Content 09:24 — The Only Metric That Matters Online 10:20 — Why the First 3 Seconds Decide Everything 13:03 — How Travel Shaped James’ Ambition 14:25 — Turning Rejection Into Fuel 15:41 — Interviewing 52 Billionaires by 23 15:52 — How James Got Mark Cuban 17:30 — Tom Cruise, Brady, Shaq, and Bigger Asks 20:08 — Why Business Takes Courage 20:50 — Building One of the Biggest Business Media Networks Hashtags: #jamesdumoulin #schoolofhardknocks #contentcreation #goingviral #watchtime #entrepreneurship #businessmedia #founderjourney #creatoreconomy #divotpodcast

This week on Divot I interviewed James Dumoulin from The School of Hard Knocks why 3 seconds decides everything in going viral, turning rejection into fuel, how he's interviewed 50 billionaires at only 23, and how he is building his media empire on billions of views one clip at a time. Timestamps: 01:48 — How School of Hard Knocks Started 03:56 — 400 Posts With Only 50 Followers 04:41 — From $100K Months to $1M Months 06:15 — How Small Teams Can Win With Content 09:24 — The Only Metric That Matters Online 10:20 — Why the First 3 Seconds Decide Everything 13:03 — How Travel Shaped James’ Ambition 14:25 — Turning Rejection Into Fuel 15:41 — Interviewing 52 Billionaires by 23 15:52 — How James Got Mark Cuban 17:30 — Tom Cruise, Brady, Shaq, and Bigger Asks 20:08 — Why Business Takes Courage 20:50 — Building One of the Biggest Business Media Networks Hashtags: #jamesdumoulin #schoolofhardknocks #contentcreation #goingviral #watchtime #entrepreneurship #businessmedia #founderjourney #creatoreconomy #divotpodcast

Derek Andersen

14,416 次观看 • 1 个月前

"There may be some neuro-symbolic hybrid much better than we have right now that smoothly transitions between data in a corpus and abstract representations. The kinds of stuff you guys are doing are compatible with that." — Gary Marcus ⏱️10 highlights: 00:00 Intro: Gary Marcus & Brana Rakic at DKGCon 02:22 Why AI took a wrong turn 04:42 Deep learning vs. deep understanding 06:16 World models: a foundational idea 08:12 The building blocks of trustworthy AI 09:44 Neuro-symbolic AI & abstract relationships 13:04 Safety is an ecosystem - the airplane lesson 15:03 The real risk of AI agents today 18:36 Testing AI like we test new drugs 22:49 Where OpenAI is headed The signal is clear: the path forward runs through world models, abstraction, and an open, accountable ecosystem.

"There may be some neuro-symbolic hybrid much better than we have right now that smoothly transitions between data in a corpus and abstract representations. The kinds of stuff you guys are doing are compatible with that." — Gary Marcus ⏱️10 highlights: 00:00 Intro: Gary Marcus & Brana Rakic at DKGCon 02:22 Why AI took a wrong turn 04:42 Deep learning vs. deep understanding 06:16 World models: a foundational idea 08:12 The building blocks of trustworthy AI 09:44 Neuro-symbolic AI & abstract relationships 13:04 Safety is an ecosystem - the airplane lesson 15:03 The real risk of AI agents today 18:36 Testing AI like we test new drugs 22:49 Where OpenAI is headed The signal is clear: the path forward runs through world models, abstraction, and an open, accountable ecosystem.

OriginTrail

227,307 次观看 • 1 个月前

The complete playbook for building profitable companies in the AI age 1. Go heads down 2. Find an underserved niche + trend backed by data (start small) 3. Learn their painpoints/what content drives them 4. Come up with an idea (or steal one from Idea Browser) 5. Build an audience/community (pick 1 platform) 6. Use Manus/v0/Bolt/Lovable/Cursor to build v1 7. DM your audience, offer a discounted version 8. Reinvest that cash to fund product/content flywheel 9. Keep team small (AI is your co-founder) 10. Automate ~90%+ with agents/zaps etc 11. Reinvest profits into content + core features 12. Partner with creators in exchange for equity (1–20%) or rev share (20–50%) 13. Keep surfacing new ideas from users + trends (use agent feature on pro Idea Browser) 14. Build public-facing tools to drive top-of-funnel 15. Add modular pricing: free → $29 → $299 → $3K 16. Turn manual services into productized features 17. Build in public to attract users, partners, and acquirers 18. Bundle into an ecosystem, not just a single feature 19. Own the loop: audience → product → content → more audience 20. Run sprints on retention (fix that leaky bucket) 21. Backfill with AI agents before hiring ops roles 22. Test new channels with throwaway brands 23. Monetize the backend, sell data, leads, APIs if applicable 24. Have fun 25. Repeat. Build a portfolio 26. Share hires, tools, and infrastructure across products 27. Acquire underperforming products with distribution upside 28. Relaunch or bundle existing apps using your playbook 29. Create a holding company brand people want to follow (this is exactly what im doing, practicing what im preaching) 30. Build long-term wealth with no outside investors and infinite spins 31. Cross-promote wins across your product ecosystem to drive flywheel growth 32. Create an internal idea-to-launch pipeline (every 30 days, something ships) 33. License or clone successful products into new verticals or geos 34. Recruit niche operators to run individual products for cash + upside/profitshare 35. Build once, compound forever... audience, code, and trust all stack This is the greatest time to be an idea person. Happy building.

GREG ISENBERG

89,924 次观看 • 1 年前

Jack Keane is a retired four-star American general, former Vice Chief of Staff of the U.S. Army, and a recognized national security expert, Fox News analyst, and chairman of the Institute for the Study of War. Host: Even as he focuses on trade, the president isn't forgetting the peace agreements. He's hoping for China's support regarding Russia in Ukraine. However, he recently abandoned the idea of supplying Tomahawk missiles to Ukraine. Listen. Tomahawk missiles require a long training period. A year of intensive training is needed to master them. We can do it, but we won't train others. That would be... that's too remote a prospect. The NATO Secretary General supported the president, saying no weapon would change the course of the war. But Russia was concerned about the possibility of Ukraine receiving it. As for training, doesn't the U.S. already supply systems that require training? I mean F-16s, M1 Abrams tanks, Bradley infantry fighting vehicles, HIMARS. What's the difference, and does Ukraine really need a year to learn how to use Tomahawks? Jack Keane: Well, I think to train someone in an American school after basic training takes six months to a year. That applies to training on tanks, Patriot batteries, or other equipment. But for the Ukrainians, we have very compact programs. They don't just learn on weekdays. They work seven days a week, 14-15 hours a day, Jackie. And these programs, even the compact ones, would take six weeks for Tomahawks, but they probably do it faster. They've exceeded our expectations in everything we've given them. M1 tanks, HIMARS, ATACMS, Patriot missiles. And why? War sharpens the mind. They approach it with incredible determination, and that's completely understandable. There was never a weapon system we wanted to give them where training would have been a barrier to deployment. Maybe there are other reasons, but I don't think that should be the reason. The president probably has information that, in my opinion, is inconsistent with our experience with the Ukrainians and what we would do with that system. Look, so what's the problem? The problem is that Russia has a safe haven beyond the reach of all available weapons systems from the US, Europe, and Ukraine. Aside from drones, they can't reach them. The main target is the Shahed drone production center in Alabuzi. These are drones that fly in swarms of 500-800 at night, attacking mainly major cities in Ukraine. This is a very serious problem. This center was built by Iranians. 20,000 North Koreans [?] work there. And that's target number one. Other targets are bomber bases that fire missiles at Ukrainian cities and civilians. That's why Ukraine wants these weapons. Observers like myself believe that this is precisely why we must provide them. It makes no sense to deny the Ukrainians the opportunity to protect their population when Putin has carried out the main escalation of the war against the civilian population.

Jack Keane is a retired four-star American general, former Vice Chief of Staff of the U.S. Army, and a recognized national security expert, Fox News analyst, and chairman of the Institute for the Study of War. Host: Even as he focuses on trade, the president isn't forgetting the peace agreements. He's hoping for China's support regarding Russia in Ukraine. However, he recently abandoned the idea of supplying Tomahawk missiles to Ukraine. Listen. Tomahawk missiles require a long training period. A year of intensive training is needed to master them. We can do it, but we won't train others. That would be... that's too remote a prospect. The NATO Secretary General supported the president, saying no weapon would change the course of the war. But Russia was concerned about the possibility of Ukraine receiving it. As for training, doesn't the U.S. already supply systems that require training? I mean F-16s, M1 Abrams tanks, Bradley infantry fighting vehicles, HIMARS. What's the difference, and does Ukraine really need a year to learn how to use Tomahawks? Jack Keane: Well, I think to train someone in an American school after basic training takes six months to a year. That applies to training on tanks, Patriot batteries, or other equipment. But for the Ukrainians, we have very compact programs. They don't just learn on weekdays. They work seven days a week, 14-15 hours a day, Jackie. And these programs, even the compact ones, would take six weeks for Tomahawks, but they probably do it faster. They've exceeded our expectations in everything we've given them. M1 tanks, HIMARS, ATACMS, Patriot missiles. And why? War sharpens the mind. They approach it with incredible determination, and that's completely understandable. There was never a weapon system we wanted to give them where training would have been a barrier to deployment. Maybe there are other reasons, but I don't think that should be the reason. The president probably has information that, in my opinion, is inconsistent with our experience with the Ukrainians and what we would do with that system. Look, so what's the problem? The problem is that Russia has a safe haven beyond the reach of all available weapons systems from the US, Europe, and Ukraine. Aside from drones, they can't reach them. The main target is the Shahed drone production center in Alabuzi. These are drones that fly in swarms of 500-800 at night, attacking mainly major cities in Ukraine. This is a very serious problem. This center was built by Iranians. 20,000 North Koreans [?] work there. And that's target number one. Other targets are bomber bases that fire missiles at Ukrainian cities and civilians. That's why Ukraine wants these weapons. Observers like myself believe that this is precisely why we must provide them. It makes no sense to deny the Ukrainians the opportunity to protect their population when Putin has carried out the main escalation of the war against the civilian population.

Jürgen Nauditt 🇩🇪🇺🇦

35,558 次观看 • 8 个月前

Why Ethereum’s New Marketing Arm Is Convinced Wall Street Will Adopt ETH Ethereum has faced a tough year (or even more 👀), but Vivek Raman, founder of Etherealize, says the tide is turning. 🌊 Why he believes Ethereum can solidify its lead in institutional adoption 🥊 How he thinks it stacks up against rivals like Solana? Timestamps: ⏳ 02:50 Why Vivek believes now is the perfect time to launch Etherealize 🔍 07:32 The behind-the-scenes work that started long before the launch 💸 13:28 Why Vitalik Buterin and the Ethereum Foundation backed the project 🎯 15:11 Vivek’s take on the fortunate timing of the announcement 📈 19:03 Driving the narrative of ETH as an institutional-grade asset 🏢 22:17 Whether L2s are ideal for corporate scalability and customization 🤝 29:13 Vivek’s pitch for Ethereum to TradFi 🏛️ 31:42 Why Ethereum is a better fit for Wall Street than Solana, according to Vivek ⚖️ 34:08 Addressing concerns over L2 centralization Thank you to our sponsors! Quai Network ⚡️💵 Polkadot

Why Ethereum’s New Marketing Arm Is Convinced Wall Street Will Adopt ETH Ethereum has faced a tough year (or even more 👀), but Vivek Raman, founder of Etherealize, says the tide is turning. 🌊 Why he believes Ethereum can solidify its lead in institutional adoption 🥊 How he thinks it stacks up against rivals like Solana? Timestamps: ⏳ 02:50 Why Vivek believes now is the perfect time to launch Etherealize 🔍 07:32 The behind-the-scenes work that started long before the launch 💸 13:28 Why Vitalik Buterin and the Ethereum Foundation backed the project 🎯 15:11 Vivek’s take on the fortunate timing of the announcement 📈 19:03 Driving the narrative of ETH as an institutional-grade asset 🏢 22:17 Whether L2s are ideal for corporate scalability and customization 🤝 29:13 Vivek’s pitch for Ethereum to TradFi 🏛️ 31:42 Why Ethereum is a better fit for Wall Street than Solana, according to Vivek ⚖️ 34:08 Addressing concerns over L2 centralization Thank you to our sponsors! Quai Network ⚡️💵 Polkadot

Laura Shin

93,550 次观看 • 1 年前

From Airbnb to the Trump Administration's DOGE initiative—my conversation with Airbnb co-founder Joe Gebbia covers his remarkable journey and what's next. 0:00 - Introduction 1:14 - Joe’s background 3:13 - First website 4:57 - Airbnb foudning 11:07 - First guests 15:04 - South by Southwest 17:48 - Trough of sorrow 18:56 - Selling cereal to keep dream alive 20:43 - Holding a grudge 21:13 - First investor pitch 23:54 - Building trust 24:37 - Greatest unforeseen challenge 26:59 - Favorite Airbnb 30:48 - Backing President Trump 32:19 - Macrobiotic diet 34:00 - Make America Healthy Again 34:37 - Biden’s border crisis 36:47 - America’s Chief Design Officer 39:43 - Improving the retirement process 41:46 - National Design Studio 45:46 - The private sector versus government 46:50 - First government website redesign 48:39 - Serving in the Trump Administration 50:37 - Being a billionaire 55:50 - Rapid fire questions 57:51 - Would You Rather 59:52 - Departing Airbnb 1:01:29 - Worst idea 1:02:07 - Best investment 1:02:38 - Genuine intentions 1:04:27 - Dream dinner party 1:06:02 - Next endeavor

From Airbnb to the Trump Administration's DOGE initiative—my conversation with Airbnb co-founder Joe Gebbia covers his remarkable journey and what's next. 0:00 - Introduction 1:14 - Joe’s background 3:13 - First website 4:57 - Airbnb foudning 11:07 - First guests 15:04 - South by Southwest 17:48 - Trough of sorrow 18:56 - Selling cereal to keep dream alive 20:43 - Holding a grudge 21:13 - First investor pitch 23:54 - Building trust 24:37 - Greatest unforeseen challenge 26:59 - Favorite Airbnb 30:48 - Backing President Trump 32:19 - Macrobiotic diet 34:00 - Make America Healthy Again 34:37 - Biden’s border crisis 36:47 - America’s Chief Design Officer 39:43 - Improving the retirement process 41:46 - National Design Studio 45:46 - The private sector versus government 46:50 - First government website redesign 48:39 - Serving in the Trump Administration 50:37 - Being a billionaire 55:50 - Rapid fire questions 57:51 - Would You Rather 59:52 - Departing Airbnb 1:01:29 - Worst idea 1:02:07 - Best investment 1:02:38 - Genuine intentions 1:04:27 - Dream dinner party 1:06:02 - Next endeavor

The Katie Miller Podcast

1,266,044 次观看 • 10 个月前

how to build, launch and grow your startup: complete basics that every founder learns by accident 00:00 Intro to building 00:14 The build-measure-learn loop 04:12 What makes a good one-liner 05:40 Rewriting bad one-liners 08:43 Billboards: the Monaco trick 10:12 Set a specific 5-week goal 13:43 Goals that never end will break you 15:42 Intro to Content 18:15 Why luck is the real product 25:03 Fix your bio right now 28:24 Cheat sheet for viral launches 30:49 Step 1: Find 10 strangers (not founders) 33:07 Step 2: The "oh, that makes sense" moment 34:26 Step 3: A visually clear use case 42:29 The $100 launch video that hit 4M 46:04 Context in the first 2 seconds 48:15 Writing with an eraser 51:11 Framework 1: Comparison 54:29 Framework 2: Antagonist 56:01 Framework 3: The Gap 59:37 Be the world's leading expert 01:06:42 Steal your customer's FYP 01:11:47 The 25-video spreadsheet 01:19:36 Intro to Growth 01:21:32 The only metric that matters 01:23:20 Why 1M LP hits is bad growth 01:26:53 The #1 rule on user calls 01:27:15 The AI realtor story 01:34:19 Why Reddit beats Twitter 01:40:15 The landing page that turns pink

how to build, launch and grow your startup: complete basics that every founder learns by accident 00:00 Intro to building 00:14 The build-measure-learn loop 04:12 What makes a good one-liner 05:40 Rewriting bad one-liners 08:43 Billboards: the Monaco trick 10:12 Set a specific 5-week goal 13:43 Goals that never end will break you 15:42 Intro to Content 18:15 Why luck is the real product 25:03 Fix your bio right now 28:24 Cheat sheet for viral launches 30:49 Step 1: Find 10 strangers (not founders) 33:07 Step 2: The "oh, that makes sense" moment 34:26 Step 3: A visually clear use case 42:29 The $100 launch video that hit 4M 46:04 Context in the first 2 seconds 48:15 Writing with an eraser 51:11 Framework 1: Comparison 54:29 Framework 2: Antagonist 56:01 Framework 3: The Gap 59:37 Be the world's leading expert 01:06:42 Steal your customer's FYP 01:11:47 The 25-video spreadsheet 01:19:36 Intro to Growth 01:21:32 The only metric that matters 01:23:20 Why 1M LP hits is bad growth 01:26:53 The #1 rule on user calls 01:27:15 The AI realtor story 01:34:19 Why Reddit beats Twitter 01:40:15 The landing page that turns pink

Founders Inc

20,720 次观看 • 2 个月前

Every movement starts somewhere. Ours didn’t start with hype. It started with a mirror. The Birth of The Mirror Hub The Mirror Hub was not born from hype or shortcuts. It was born from conviction. In early 2025, Mrs Evelyn Ayawari Damilola Spare stood at the center of an idea one that believed African youths deserved more than surface-level Web3 exposure. They deserved depth, structure, ownership, and a future-proof path. By her side was her husband, co-founder, strategist, and builder providing strength, balance, and execution power. Together, they laid the foundation of what would become The Mirror Hub. The vision was simple but bold: To reflect Web3 education, innovation, and opportunity back to the next generation clearly, truthfully, and powerfully. From that vision, a small team formed. Then the team grew. By mid-2025, The Mirror Hub had evolved into a core team of 15 committed individuals, cutting across: Community Building Education & Training Marketing & Growth Content Creation Development Research Consultation Program Management Different backgrounds. Different strengths. One mission.

Every movement starts somewhere. Ours didn’t start with hype. It started with a mirror. The Birth of The Mirror Hub The Mirror Hub was not born from hype or shortcuts. It was born from conviction. In early 2025, Mrs Evelyn Ayawari Damilola Spare stood at the center of an idea one that believed African youths deserved more than surface-level Web3 exposure. They deserved depth, structure, ownership, and a future-proof path. By her side was her husband, co-founder, strategist, and builder providing strength, balance, and execution power. Together, they laid the foundation of what would become The Mirror Hub. The vision was simple but bold: To reflect Web3 education, innovation, and opportunity back to the next generation clearly, truthfully, and powerfully. From that vision, a small team formed. Then the team grew. By mid-2025, The Mirror Hub had evolved into a core team of 15 committed individuals, cutting across: Community Building Education & Training Marketing & Growth Content Creation Development Research Consultation Program Management Different backgrounds. Different strengths. One mission.

The Mirror Hub

18,098 次观看 • 6 个月前