Metal Enrichment Histories of Dwarf Galaxies in the Local Group Based on Model Analysis of Observed Stellar Metallicity and Star Formation HistoriesMetal Enrichment Histories of Dwarf Galaxies in the Local Group Based on Model Analysis of Observed Stellar Metallicity and Star Formation Histories 観測された星の金属量と星形成史のモデル解析による、局所銀河群における矮小銀河の化学進化の研究