In this work, we discuss the accuracy of measurements for electromagnetic. The two kinds of antenna we use are Dipole antenna and Broadband antenna. In general, if the antenna measurements we recorded at different frequencies do not exceed the ideal value $pm 4$dB, we would regard this site as a normalized site, otherwise it is not a normalized site(just a measurement exceeds the range). Traditionally, all we use is Dipole antenna, but due to difficulty of operation and inaccuracy of Dipole antenna, we investigate by statistical methods if we may use the Broadband antenna to replace the traditional Dipole antenna to measure. First of all, we introduce the data and procedure in the experiments, and fit a statistical regression model to predict the measurements at different frequencies in different test setups. Then, according to the data we collected, use the change point models to modify the statistical models. Our goal is to find a suitable statistical model for the measurements. Finally, we compare the measurements of Broadband antenna with Dipole antenna in the other experimental conditions keep the same.

自民國91年，國內法令准許私募，私募是指公司的內部人，透過協商，尋求願意投資公司的投資人，把公司的股票，售給少數的投資人，不需經過承銷商，揭露也比較少。 國外的文獻，有些學者實證的結果，私募宣告時有正的異常報酬，但有些學者實證的結果發現有負的異常報酬，本篇主要探討國內宣告私募時，對公司價值的影響，以及國內公司大多屬於家族企業，在這麼高的控制權之下，股權集中度對於私募發行公司的價值又有什麼影響？ 實證的結果發現，國內公司宣告私募時有正的異常報酬，除了資訊不對稱會影響公司價值之外，本文還發現，公司在私募時，家族集團的控股如果低於30%時，增加公司持股，可以增加公司的價值，但當家族集團的股權超過30%時，就不明顯了。 此外，當股權集中度在10%~30%時，公司價值的變化與股權集中度成反比，顯示國內股權集中度在10%~30%時，符合利益掠奪假（Entrenchment Hypothesis），增加公司的股權集中度反而會減少公司的價值。

No description available.

可轉換公司債兼具了選擇權以及債券的性質，價值又會受到股價之影響，以傳統的方法定價十分不易。由於蒙地卡羅模擬能解決定價問題上狀態變數或許為多維度及路徑相依的問題，Kind 與Wilde 在2004 年提出以蒙地卡羅模擬對可轉債定價，且以最小平方迴歸法估計繼續持有價值，並在僅考慮轉換及還本兩種選擇權及沒有違約風險之下，以數值範例呈現單一迴歸模式無法適當估計繼續持有價值。然而，他們並未進行實證。本研究乃以民國99 年台灣發行的可轉債為研究對象，除考慮發行時的合約條件外，另加上信用評等的考量以將違約機率透過現金流量套入定價過程中，並分別以兩段迴歸及單一迴歸估計繼續持有價值以結合蒙地卡羅模擬，實證結果顯示就可轉債之起始定價的偏差比而言，兩段迴歸得到的結果優於單一迴歸。惟在兩段迴歸之下，超過八成的可轉債其模擬價格依然高於市場價格。實證結果也顯示價性(moneyness)及擔保狀況與定價的偏差有關。 / Convertible bonds (CBs) possess features of both bonds and options, and their prices are affected by the underlying stocks, which make the pricing problem an uneasy task for traditional methods. Since Monte Carlo simulation can handle the problems of path-dependence and multivariate dimensions faced by pricing, Kind and Wilde (2004) suggested to price CBs via least-squares Monte Carlo simulations (LSM), which estimate the continuation values by least squares regression. They also demonstrated that a single regression line could not appropriately estimate the continuation value even only conversion and redemption were allowed and the CB was free of default. So the idea of piecewise regression was recommended to improve the estimation process. However, they didn’t apply piecewise regression to real data. Therefore, piecewise regression together with Monte Carlo simulation were employed to investigate the pricing issue of Taiwan’s CBs. CBs issued on 2010 were selected, besides reviewing the contents of CB’s contracts, default risks based on credit ratings were taken into account to evaluate the discounted cash flows in the pricing procedure. Comparing the estimated model prices of LSM with initial selling prices, the mispricing rates of single regression model and piecewise regression model were obtained for further analysis. Result shows that the modified piecewise regression method performs better in mispricing rate. However, similar to previous findings, 80% of the estimated model prices based on piecewise regressions are still higher than market prices. It also shows that moneyness and guaranteed condition will relate to mispricing rate.