查詢結果分析
相關文獻
- The Effect of Changes in the Internal Structure of a Schooling Fish on the Estimation Efficiency by Acoustic Methods
- The Use of Stationary Hydroacoustic Transducer to Study Diel and Seasonal Influences on the Distribution of Fish School in Water Adjacent to the Cooling Water Intake of Nuclear Power Plant III
- Estimation of Abundance of Carangids Near the Water Intake of Nuclear Power Plant I by Dual-Beam Hydroacoustic Methods
- Quantitative Extimation of Zooplankton and Micronekton Biomass Using A High-Frequency Acoustic Method
- 魚群探測器信號定量化之處理及不同體形魚體對超音波反射強度之比較
- 魚群探測器信號定量化之處理及不同體形魚體對超音波反射強度之比較
- Transcatheter Closure of Atrial Septal Defect Guided by On-Line Transesophageal Echocardiography
- Pelvic Abscess after Ultrasound-Guided Aspiration of Endometrioma: A Case Report
- Color Doppler Ultrasound Velocimetry of Internal Carotid Arteries in Normal Pregnancies
- Intraluminal Mucin Pool in Mucinous Gastric Adenocarcinoma: A Case Report
頁籤選單縮合
題 名 | The Effect of Changes in the Internal Structure of a Schooling Fish on the Estimation Efficiency by Acoustic Methods=魚群單群結構改變對超音波評估魚群量結果之影響 |
---|---|
作 者 | 吳龍靜; 李國添; 周世欽; | 書刊名 | 臺灣水產學會刊 |
卷 期 | 19:3 1992.09[民81.09] |
頁 次 | 頁199-210 |
分類號 | 439.2 |
關鍵詞 | 魚群; 單群結構; 超音波; 超音波迅捷評估法; 評估精確度; 日本鮆; Acoustic quick assessment; Structure of a fish school; Estimate accuracy; Engraulis japonica; |
語 文 | 英文(English) |
中文摘要 | 為探討魚群單群結構改變對超音波評估的影響程度,本實驗乃以日本鮆為對評估象魚種,利用光學聲學連動系統進行計劃,由超音波回訊評估之群集密度及成對立體照片組解析之實際魚群密度,探討不同單群結構的評估誤差。由本實驗50組成對立體照片分析結果發現,日本鮆魚群之單群結構大致上可區分為規律性及塊狀分佈兩種,而這兩種截然不同的魚群,超音波群內積分法所評估的準確度也有相當大的差別,呈規律性的魚群,超音波法評估的魚群密度值與實際魚群密度較為接近,其誤差在20%內,至於成塊狀結構的魚群,則超音波的評估結果十分不穩定,且通常誤差率頗大,有高達一倍以上者,顯示魚群單群結構改變會對超音波的評估結果產生相當大的影響。並且魚群密度愈低,其單群結構愈容易產生變化,超音波回訊積分法的評估誤差率愈高。因此,當利用超音波評估魚群量時,對單群因外在因素導致行為變化,使單群結構改變時之回訊應該予以剔除,以增加評估之準確度。 |
英文摘要 | The present study investigated the effect of changes in the internal structure of schooloing Engraulis japonica on the measurement efficiency of acoustic methods. A hydroacoustic system incorporated with an underwater camera system was used to compare the packing density estimated by acoustic systems with the actual value obtained from the analysis of paired 3-dimension photograph sets. An analysis on 50 sets of paired 3-dimension photographs showed that two kinds of structures were usually present in a single E. japonica school. For fish in regular spacing schools, an estimated value of less than 20% errors could be obtained. However, large errors were usually present in the packing density of clump schools. Since fish schools with low density change their internal structures easily, errors in stock assessment also became larger for acoustic methods. Thus when the internal structure of a schooling fish was changed due to environmental factors, echo signals during structural changes should be deleted from integration to increase the accuracy of an acoustic method in abundance estimation. |
本系統中英文摘要資訊取自各篇刊載內容。