TheStreet.com Ratings provides exclusive stock, ETF and mutual fund ratings and commentary based on award-winning, proprietary tools. Its "safety first" approach to investing aims to reduce risk while seeking outperformance on a total return basis.TheStreet.com's stock-rating model upgraded EMC ( EMC) to "buy." The company develops and sells data-storage products. The numbers: First-quarter revenue decreased 9.2% from a year earlier to $3.1 billion as net income declined 23% to $194 million and earnings per share fell 17% to 10 cents. Operating margin dropped from 12% to 9% and net margin decreased from 7% to 6%. The Hopkinton, Mass.-based company boosted its cash balance 29% to $7.2 billion as it cut debt obligations 13% to $3 billion. A quick ratio of 1.8 and a debt-to-equity ratio of 0.2 indicate a strong balance sheet. The stock: EMC has rallied 29% this year, outperforming major U.S. indices. The stock is expensive, trading at a price-to-earnings ratio of 21. Like many of its tech peers, EMC doesn't pay dividends. The model upgraded Japan-based Nidec ( NJ) to "buy." The company makes motors and components for appliances, computers and industrial equipment. The numbers: Fiscal fourth-quarter revenue plummeted 72% to $667 million. Net income and earnings per share dropped 67% to $35 million and 6 cents, respectively, as net margin inched up to 5%. The company has doubled its cash reserves to $2 billion, pushing its quick ratio past 1, a measure of adequate liquidity. However, the company also doubled its debt to $2.3 billion. The stock: Nidec has surged 68% this year on signs of economic improvement and a tech spending rebound. The stock trades at an expensive price-to-earnings ratio of 30 and offers a dividend yield less than 1%.