## network – MacBook unable to visit websites while connected to Wifi

A month ago I made a wrong manipulation in the Network settings of my computer and since then I cannot browse any websites nor use the Mail app when I connect to my office’s WiFi or at the local café. There, I need to connect to my phone’s 4G in order to browse and check my emails normally, which obviously consumes a lot of data. Another way to be able connect there is to use a VPN. But without the VPN activated, I’m unable to connect.

When I am at home, it connects normally. So there is somewhere some incompatibility with other networks. Is it a DNS or proxy problem ? How can I solve this ?

## algorithms – Optimization problem over bidirectional connected graph

A company has several automatic vertical warehouses (called elevators). Each elevator have several trays and each tray has several slots. A slot contains a given quantity of a given article. Elevators, trays and slots are identified by unique IDs and slot also have access to the ID of their own article. In the same tray there can be multiple slots with the same article.

I have to design an algorithm which, given an order list (we can model it as a dictionary with articles’ IDs as key and quantity needed as values), returns the minimum list of trays needed to satisfy the order.

This is quite different from a standard warehouse optimization problem because we are not considering the physical distances between each tray, since the elevators are automatic and they give us the tray, while in the classical problem is the human who moves toward the tray to pick the item from it.

A distance function is given: d(a, b) which returns 1 if tray a and b are on different elevators and returns 2 if they’re on the same one. That could be counter-intuitive, but remember that these are vertical elevators, so the time needed to change tray on the same elevator is greater than the time to move to a different elevator with the tray already in bay. Furthermore, if we use more elevators at the same time, we can “parallelize” the picking process (man A pick from elevator 1 while man B picks from elevator 2…) Anyway, this function is given and I cannot change it.

After reading through articles about warehouse optimization, I’ve decided to take an heuristic approach.
I’ve modeled a sort of euclidean space, with an axes for each article contained in the order. Then we can consider a tray as a point on that space, with coordinates for each axes equal to the quantity that tray has of the article corresponding to that axes. In the same way we can imagine our order as a point.
Then I’ve create a heuristic function, f(order o, tray t), which returns the “euclidean distance” from point-tray t to the point-order o. The idea is that the more a tray is “near” the order, the more article we can pick out of it.

So, to satisfy the order, I simply compute f(order o, tray t) for each tray in every elevator. Then I order it by descending value and finally I greedily take a tray with the minimum distance from the order. This will be repeated until we collect enough articles to satisfy the order.

Now I `d like to find a better solution, taking into account also the physical distances from tray returned by function d.

I`ve tried to build a graph in which each node is a tray and is connected to each of the others by a directed edge. The weights of the edge from node i to node j will be equal to the physical distance from tray i to tray j, plus the heuristic function computed on tray j

``````--> w(i, j) = d(i, j) + f(order, j)
``````

This results in a fully-connected, bidirectional graph (each node linked with each other node by both an incoming and an outgoing edge).
I want to apply some algorithm of shortest path (or any other useful algorithm) taken from graph theory on this graph but I couldn`t find anything really helpful. I`ve tried to apply the A* search algorithm (using function d as gScore and my function f as heuristic) but it gives me no result. I think A* can`t be applied in such a graph (bidirectional and fully connected).

Is there any algorithm I can apply on such a graph? Or maybe the graph is not the right structure to represent my problem. I$$`$$m open to new solutions.

## Two non constant meromorphic functions over a connected compact Riemann surface, could not be algebraically independent

Let $$M$$ be a connected compact Riemann surface. Let $$f, g$$ be two nonconstant meromorphic functions. Why is there a two-variable complex polynomial $$F(x,y)$$ that vanishes for $$(x, y)=(f, g)$$, (in other words $$F(f,g)=0$$)?

## ios – How to stop iPhone auto reducing volume when it is connected via BT to things that are NOT headphones?

I understand apple has my wellbeing at heart by trying to lower the volume when listening to music (with the volume set to full), but this makes no sense why I am connected to a bluetooth speaker.

It doesn’t even ask me ‘are these headphones?’ like it does when you connect something to the lightning port.

How can I make it realise these are not headphones that are being connected?

## general topology – Are Jordan Domains Locally Connected?

I have been trying to answer this question, to which I do not know the answer. Are Jordan Domains locally connected?

In this context, a Jordan Domain is just the bounded interior of a Jordan curve.

Edit: In fact, I know the answer. It is true due to the Caratheodory Extension theorem. However, could it be proven using exclusively topological arguments?

## Checking uniqueness of a maximum unweighted matching on a bipartite connected graph

Given a maximum unweighted matching $$M$$ on a bipartite connected graph $$G = (A cup B, E)$$, a maximum matching is unique exactly when for all matchings $$M’ neq M$$, the following is true: $$|M’| < |M|$$

1. Given the maximum matching $$M$$, find an efficient algorithm that checks, if the maximum Matching is unique. Prove the correctness of your approach.

2. Given a perfect matching $$M’$$ in $$G$$ ($$|M’| = |A| = |B|$$) – Describe an efficient algorithm that checks for a given edge $$e in M’$$ whether there is an alternate maximum matching, which does not contain $$e$$

My ideas:

I think for the first one, it’s probably something using an augmenting Path. I figure if you find a path where every other edge is matched, that either ends in a cycle or on a node with no matched edge connecting to it, you would be able to get it, but I have no idea to turn that idea into an efficient algorithm.

For the second question, I guess you would probably also use an augmenting path, starting with $$e$$, probably something similar to the first one, I imagine

## ora-03114 not connected to oracle

Since the upgrade to the 19C Oracle DB (before 12C) I receive randomly those ORA-03114 error message’s.
Before the upgrade I never received it. Any idea’s what exactly why those error messages pops up suddenly and what changes needs to be done?

• Domain Win10 PC
• Not all PC’s in the domain having this issue
• only localy tnsnames.ora change

## networking – Meraki Wireless Repeaters not allowing connected clients to access LAN devices but Gateways are?

I am trying to set up a Meraki Mesh network(Mesh1) at a small remote office. I have 1 MX65W and 3 MR36’s, 1 acting as the gateway and the other 2 as repeaters. The SSID I’m broadcasting is set to operate in bridge mode, and it’s connected to a VLAN that is connected to a VPN tunnel back to the main office network(Corp1). From my laptop on Corp1, I can ping devices that are connected directly to the MX65 via a wired connection, and I can ping devices that are connected wirelessly to the Gateway AP. However, I can’t ping devices that are connected to either of the 2 repeaters.

The 3 AP’s appear to have Meshed successfully and devices connected to the repeaters can still access the internet and are getting IP’s in the correct subnet, they just can’t seem to communicate with anything on Corp1. Is there some kind of security setting I’m missing? How do I get the repeaters to communicate with the corporate network like the Gateway is already doing?

## How do internet wallets connected to full blockchain nodes

How do internet wallets such as Coinbase connect to the a blockchain node? Doesn’t the node itself create a default wallet object on startup? How is this replaced by internet wallets which hold multiple address until account credentials.

## coding – how to create a warehouse software with Google sheet connected with e-commerce?

I have been trying for about 1 year to transform a warehouse management software built on google sheet using google app script, I would like it to be able to connect to an e-commerce with the products that are inside it and that it is always updated based on the changes that are carried out on Google Sheets. could someone point me in the right way? Thanks in advance for your answers.