• 제목/요약/키워드: side fish

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50 kHz 체장어군탐지기용 분할 빔 음향 변환기의 지향성 보정 및 위치각 추정 (Estimation of Angular Location and Directivity Compensation of Split-beam Acoustic Transducer for a 50 kHz Fish Sizing Echo Sounder)

  • 이대재
    • 한국수산과학회지
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    • 제44권4호
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    • pp.423-430
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    • 2011
  • The most satisfactory split-beam transducer for fish sizing maintains a wide bearing angle region for correct fish tracking without interference from side lobes and lower sensitivity to fish echoes outside of the main lobe region to correctly measure the angular location of free-swimming fishes in the sound beam. To evaluate the performance of an experimentally developed 50 kHz split-beam transducer, the angular location of a target was derived from the electrical phase difference between the resultant signals for the pair of transducer quadrants in the horizontal and vertical planes consisting of 32 transducer elements. The electrical phase difference was calculated by cross-spectral density analysis for the signals from the pair of receiving transducer quadrants, and the directivity correction factor for a developed split-beam transducer was estimated as the fourth-order polynomial of the off-axis beam angle for the angular location of the target. The experimental results demonstrate that the distance between the acoustic centers for the pair of receiving transducer quadrants can be controlled to less than one wavelength by optimization with amplitude-weighting transformers, and a smaller center spacing provides a range of greater angular location for tracking of a fish target. In particular, a side lobe level of -25.2 dB and an intercenter spacing of $0.96\lambda$($\lambda$= wavelength) obtained in this study suggest that the angular location of fish targets distributing within a range of approximately ${\pm}28^{\circ}$ without interference from side lobes can be measured.

이스라엘 잉어 Cyprinus Carpio의 체장 , 체중별 초음파 표적강도에 관한 연구 (Ultrasonic Target Strength of Cyprinus Carpio in Accordance with Body Length and Body Weight)

  • 신형호;윤갑동;박해훈
    • 수산해양기술연구
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    • 제25권4호
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    • pp.191-199
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    • 1989
  • 본 연구에서는 이스라엘잉어 Cyprinus carpio를 체장과 체중별로 분류하여 방위별 표적강도를 측정한 후, 체장 및 체중의 변화에 따른 표적강도와의 관계를 고찰하였으며, 그 결과는 다음과 같다. 1. 이스라엘잉어를 대상으로 하여 측정된 방위별 표적강도는 부레의 위치변화에 따라 심한 변화폭을 보였으나, 대체적으로 최대표적강도의 방위별 분포는 dorsal aspect인 경우 등쪽을 기준하여 $10^{\circ}$ 정도의 방위변화에서 최대였으며, side aspect인 경우 음원의 수직 측면상의 5$^{\circ}$~$10^{\circ}$에서 최대였다. 2. 이스라엘잉어에 대한 체장, 체중별 표적강도는 체장과 체중에 비례하여 지수함수적으로 증가하였으며, 체장(L) 및 체중(W)의 변화에 따른 표적강도의 관계식은 다음과 같다. TS sub(L)=20 LogL-65.4. TS sub(W)=6.7 Log W-53.7. TS sub(L): 체장에 대한 표적강도(dB). TS sub(W): 체중에 대한 표적강도(dB).

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GROWTH AND FEED UTILIZATION IN BLACK BENGAL GOATS ON ROAD SIDE GRASS BASED DIET SUPPLEMENT WITH FISH MEAL AND UREA MOLASSES BLOCK

  • Huq, M.A.;Akhter, S.;Hashem, M.A.;Howlider, M.A.R.;Saadullah, M.;Hossain, M.M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권2호
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    • pp.155-158
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    • 1996
  • Seventy two Black Bengal goats on road side grass based diet were fed on 0, 20, 40, 80, 100 or 120 g of fish meal (FM)/goat/day with or without ad libitum access to urea molasses block(UMB). The purpose was to assess the interaction of undegradable protein (UDP) and fermentable nitrogen(N) supplementation on feed intake, nutrient digestibility and growth of goats. Live weight gain of goats increased linearly with the increasing of dietary fish meal as an undegradable protein source. With the increasing level of fish meal the live weight gain(g/day) was 17, 23, 46, 48, 48 and 52 with urea molasses block and 12, 21, 31, 49, 47 and 47 without urea molasses block. It was concluded that the beneficial effects of urea molasses feeding to accelerate the dry matter intake, TDN intake and nutrient digestibility observed could not be exploited in terms of live weight gain.

Effects of Stocking Density on the Blind-side Hypermelanosis of Cultured Olive Flounder Paralichthys olivaceus

  • Kang, Duk-Young;Kim, Hyo-Chan;Chang, Young-Jin
    • Fisheries and Aquatic Sciences
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    • 제14권2호
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    • pp.123-129
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    • 2011
  • To determine whether rearing density affects the hypermelanosis on the blind side (ambicoloration) of olive flounders Paralichthys olivaceus, we reared fry with an unpigmented non-eyed (blind) side in duplicate at densities of 150 individuals/$m^2$ (commercial production density: control) and 450 individuals/$m^2$ (high density group) for 90 days in 1-t dark-green fiberglass reinforced plastics (FRP) tank. We recorded feed intake, feed conversion efficiency (FE), growth and survival, and measured the ratios of staining blind-side area (staining area) and ambicolored fish every 30 days. Daily feed intake (DFI), feed conversion efficiency (FE), growth rate, condition factors, and survival rate were calculated at the end of the experiment. Although the FE was higher in the high-density compared to the control, the two density groups showed similar feed intakes, growth, and survival. The ratio of staining area as well as the ratio of ambicolored fish significantly were significantly higher in the high-density group than in the control from days 30 to 60, but significantly increased and evened out by the end of the experiment (P<0.05). In conclusion, we determined that rearing density is not the main cause of the blind-side hypermelanosis, but found that increasing the rearing density can accelerate the ambicoloration in olive flounders.

50 kHz 체장어군탐지기용 분할 빔 음향 변환기의 개발 (Development of Split-beam Acoustic Transducer for a 50 kHz Fish Sizing Echo Sounder)

  • 이대재;이원섭
    • 한국수산과학회지
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    • 제44권4호
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    • pp.413-422
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    • 2011
  • An improved split-beam transducer for a 50 kHz fish-sizing echo sounder was developed. The main objective of this study was to minimize the side lobe level in the beam pattern and the distance between acoustic centers for adjacent transducer quadrants in the geometrical arrangement of array elements while maintaining a given number of transducer elements and beam width. To achieve these goals, a 32-element planar array transducer ($6{\times}6$ array with one element in each corner missing) was designed using the Dolph-Chebyshev shading function to suppress side lobes in the array beam pattern and fabricated by arranging the inter-element spacing to be substantially equal to half the wavelength using the transducer element of 0.4 times the wavelength in diameter. The performance characteristics of this split-beam transducer were evaluated in the experimental water tank of $5m{\times}5m{\times}6m$ (length${\times}$height${\times}$width). In this study, the design goal of the beam width and side lobe level for transmitting a beam pattern was initially set at $21^{\circ}$ and -30 dB, respectively. However, the measured beam width at 3 dB was $21^{\circ}$ in both directions with side lobe levels of -24.7 dB in the horizontal plane and -25.6 dB in the vertical plane. The averaged beam width at -3 dB of the receiving beam patterns for four receiving quadrants was $31.4^{\circ}$. The transmitting voltage response was 161.5 dB (re $1{\mu}Pa$/V at 1 m) at 50.23 kHz with a bandwidth of 2.16 kHz, and the averaged receiving sensitivity for four receiving quadrants was -178.13 dB (re 1 V/${\mu}Pa$) at 49.8 kHz with a bandwidth of 2.64 kHz.

대학생의 음식 기호 조사 (Food Preferences of College Students)

  • 정영진
    • Journal of Nutrition and Health
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    • 제17권1호
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    • pp.10-19
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    • 1984
  • The Purpose of this study was to investigate the food preferences of college students of Korea. The survey was conducted on november, 1981 through the questionnaires. The subjects were 1184 male and 1241 female students of 9 universities. The results obtained were summarized as follows : 1) Preferences of staple foods : Cooked rice was preferred most by the subjects. Male liked rice more than female, whereas female liked bread and noodle more than male. Among the different kinds of rice, bread, and noodles, the following food items were favored by the subjects. (plain rice, red bean rice and soybean rice ; salad bread and vegetable bread ; Nangmyun and Bibim Kooksu). The foods not preferred were barley rice, instant noodle and soybean milk noodle. 2) Preference of side - dishes : Among the kinds of side - dishes by different preparation methods, stews were the most favored and the next favored were soups by the subiecls whereas female showed lower preference of soups than male subjects Most disliked kinds of side-dishes were changachi and moochim. For example, side-dishes which showed higher preference in each preparation method were stew (Kimchi stew and Soybean paste stew), soup (Beef soup and Seaweed soup), kimchi (Korean cabbage Kimchi), Bockeum (Sauted beef and Sauted Kimchil, cheon(Beef Cheon, fish Cheon), Kui(broiled saury and broiled yellow tail runner), Chorim(braised cuttle fish and braised fish cake), Namul(sliced radish, cucumber, and spinachi), and Changachi (dried radish). The side-dishes which showed lower preference were Alaskan pollack soup, soybean curd residue stew, cabbage Kimchi, liver Cheon, sauted liver, hairtail Chorim, radish rootNamul, and dried radish root Changachi. 3) Preferences of snacks. Fruits apple, peach, pear) were the most preferred snacks by the subjects. Male preferred ginsang tea whereas famale preferred coffee. Both bate and female subjects showed higher preference of milk and lower preference of sweets. 4) Preference of one-dish meals : No one dish meal were disliked by the subjects. Male liked Bockeum-Bab more than female, and female liked Mandukuk more than male subjects.

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강도다리(Platichthys stellatus) 흑화 발현에 미치는 수조색깔 및 자갈기질의 영향 (Influence of Background Color and Substratum on the Blind-side Hypermelanosis in Starry Flounder Plathchthys stellatus)

  • 김원진
    • 수산해양교육연구
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    • 제28권3호
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    • pp.841-847
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    • 2016
  • To study the influence of background color and substratum on hypermelanosis of starry flounder, we compared the daily food intake (DFI), the feed efficiency (FE), the survival, the growth, the ratio of pigmented area on the blind side and the ratio of hypermelanic fish duplicately reared for 180 days in dark-green FRP aquarium (control), white FRP aquarium together with dark-green substratum. The ratio of pigmented area on the blind side was significantly higher at the dark-green group than at the white group. DFI, FE and growth were higher in the dark-green substratum. Pigmented area rate and ratio of hypermelanic fish were significantly higher at the dark green group than at the high dark-green substratum. The results suggest that bright tank color and substratum bottom could inhibit the hypermelanosis.

전남 여수지역 산업체에 근무하는 근로자의 식품 및 음식의 기호도 조사 (Food and Meal Preference of Workers in the Chonnam Yeosu Industrial Area)

  • 한현미;최일수;정복미
    • 대한지역사회영양학회지
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    • 제14권4호
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    • pp.392-405
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    • 2009
  • This study was conducted to investigate food and meal preference of workers (435 male and 212 female) in the Chonnam Yeosu industrial area. The results of the survey were analyzed by principal components analysis. The results were obtained as follows: 19.3% of the subjects were twenties, 28.3% were thirties, 28.8% were forties and 23.7% were fifties. Females liked rice rolled in dried laver, rice cakes, janchi-noodle and breads, on the other hand males liked thick beef soup, loach soup, an eel stew and soju. The young liked instant noodles, fried chicken, sweet and sour pork, pork cutlet, pizza, hamburger, ham, sausage and fruit beverage, on the other hand the old liked a fish pot stew, loach soup, eel stew, fish boiled in soy with spices, panfried fish, sea slug, ascidian, bunder, green laver and boiled burdock-lotus root in soy. Females who are young liked hamburger and sweet and sour pork whereas males who are young liked instant noodles, pork cutlet, ham, sausage and fruit beverage. Aged females liked fish boiled in soy with spices, panfried fish, bunder, green laver, boiled burdock-lotus root in soy whereas aged males liked a fish pot stew, loach soup, eel stew, sea mussel and oysters. Boiled rice was located within the middle irrespective of age and sex, but noodles, wheat flour meal, fast foods and fruits were situated at the young female side. Aged males liked soup and pot stew. Young males liked meats and eggs whereas fish and shellfish and kimch were located at the aged people side. Aged females liked sea weeds and most people disliked vegetables but females liked some vegetables irrespective of age. Processed foods, salted foods, and alcohol were generally disliked foods by subjects but males liked those foods. Soybean curd was liked more males than females, and teas, except coffee, was liked by males. (Korean J Community Nutrition 14(4) : 392${\sim}$405, 2009)

양식장용 자동 먹이공급시스템 설계 (Design of Auto Feed Supply System for Fish Farm)

  • 오진석;조관준
    • 한국항해항만학회지
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    • 제33권10호
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    • pp.709-713
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    • 2009
  • 근해의 수질오염은 수산양식 산업에 큰 영향을 미친다. 이러한 문제점을 해결하기 위하여 근해에서 외해로 양식장이 이동하고 있다. 외해 양식장의 구축을 위해서는 자동먹이 공급장치 및 원격 관리 시스템이 필요하다. 본 논문은 해상의 양식장에서의 자동 먹이 공급 시스템에 관하여 설명하고자 한다. 어류는 수온 및 어체 중량에 따라 먹이를 먹는 양이 변화하며, 해상 양식장의 경우 육상에 비하여 온도 변화가 크게 일어난다. 본 논문은 수온 및 어체 중량에 따라 먹이량을 계산하고 자동으로 먹이를 공급하는 시스템을 연구하였으며 모형 실험을 통하여 먹이 공급 장치의 성능을 검증하였다.

외해 가두리 양식장용 먹이공급시스템 (Feed supply system for Fish farm in Ocean Sea)

  • 오진석
    • 한국항해항만학회지
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    • 제34권10호
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    • pp.793-797
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    • 2010
  • 근해의 어족자원 고갈 및 수질오염은 수산양식 산업에 큰 영향을 미친다. 이러한 문제점을 해결하기 위하여 근해에서 외해로 양식장이 이동하고 있다. 외해 양식장은 근해보다 해상환경에 강인하게 개발되어야 하며, 안정적인 양식장 운영을 위해 원격 자동먹이 공급장치가 필요하다. 본 논문은 해상의 양식장에 적합한 원격 먹이공급시스템에 관하여 기술하고자 한다. 어류는 수온 및 어체 중량에 따라 먹이를 먹는 양이 변화한다. 해상 양식장의 경우 육상에 비하여 온도 변화가 크게 일어난다. 본 논문은 수온 및 어체 중량에 따라 먹이량을 계산하고 자동으로 먹이를 공급하는 시스템을 연구하였다. 모형을 활용한 먹이 공급 장치의 성능을 실험하였다.