Toss the cucumber wedges with the salt and let them stand in a bowl for 20 minutes.
Drain the cucumbers in a colander, rinse them under cold water, and pat them dry on paper towels.In a bowl dissolve the sugar in the vinegar, stirring, add the cucumbers, and toss them to coat them with the mixture.
In a small skillet heat the sesame oil and the vegetable oil over moderately high heat until the oil is just smoking, add the gingerroot and the redpepper flakes, and stir fry the mixture for 5 - 10 seconds, or until the red pepper flakes are several shades darker.
Remove the skillet from the heat and let the oil cool to room termperature.
Pour the spiced oil over the cucumbers, toss the mixture well and let it marinate at room temperature for 1 hour.
Refrigerate and cover, stirring occasionally. Use within 5 days.