• Title/Summary/Keyword: Head Part

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Spawning Behavior and Development of Eggs and Larvae of the Korea Freshwater Goby, Rhinogobius brunneus (Gobiidae: Perciformes) (한국산 밀어 (Rhinogobius brunneus)의 산란습성, 난발생 및 자어의 형태발달)

  • HAN Kyeong-Ho;KIM Yong Uk;CHOE Kyu-Jung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.1
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    • pp.114-120
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    • 1998
  • The spawning behavior, development of eggs and larvae of the Korea freshwater goby, Rhinogobius brunneus (Temminck et Schlegel) were studied. The eggs were spawned as a one-layer mass, hanging from the underside of a small pebble, and guarded by one male. The eggs were elliptic, about 1.48 mm in length and 0.65 mm in breadth, with a round top and a somewhat flat base with glutinous fibers. Hatching in the indoor tank with $17.0^{\circ}C$ in mean water temperature started from the 146 hours after fertilization. In the late developing stages, the embryo moved and freely changed its head to face the free tip of the chorion (normal egg) or to the basal end with a boundle of adhesive filaments (agrippa egg). Newly-hatched larvae were $3.10\~3.30$ mm in total length (mean: 3.22 mm), and mouth and anus were not yet open. Melanophores were present on the air- bladder, around the anus, and on the ventral part of the caudal region. The larva $3\~4$ days old transformed to postlarval stage, and they were $3.30\~3.85$ mm in total length (mean: 3.60 mm). As yolk sac and oil globules werw nearly absorbed, mouth and anus were open, and they fed rotifers actively. In $20\~22$ days after hatching the larvae grew to 5.85 mm in 71, and the caudal notochord flex at $45^{\circ}$.

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Case of assembly process review and improvement for mega-diameter slurry shield TBM through the launching area (발진부지를 이용한 초대구경 이수식 쉴드TBM 조립공정 검토 및 개선 사례)

  • Park, Jinsoo;Jun, Samsu
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.6
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    • pp.637-658
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    • 2022
  • TBM tunnel is simple with the iterative process of excavating the ground, building a segment ring-build, and backfilling. Drill & Blast, a conventional tunnel construction method, is more complicated than the TBM tunnel and has some restrictions because it repeats the inspection, drilling, charging, blasting, ventilation, muck treatment, and installation of support materials. However, the preparation work for excavation requires time and cost based on a very detailed plan compared to Drill & Blasting, which reinforces the ground and forms a tunnel after the formation of tunnel portal. This is because the TBM equipment for excavating the target ground determines the success or failure of the construction. If the TBM, an expensive order-made equipment, is incorrectly configured at the assembly stage, it becomes difficult to excavate from the initial stage as well as the main excavation stage. When the assembled shield TBM equipment is dismantled again, and a situation of re-assembly occurs, it is difficult throughout the construction period due to economic loss as well as time. Therefore, in this study, the layout and plan of the site and the assembly process for each major part of the TBM equipment were reviewed for the assembly of slurry shield TBM to construct the largest diameter road tunnel in domestic passing through the Han River and minimized interference with other processes and the efficiency of cutter head assembly and transport were analyzed and improved to suit the site conditions.

Current Status and Future Directions of the Dream Start Program in Korea (드림스타트, 지난 10년의 성장과 향후 10년을 위한 과제)

  • Lee, Sang-Gyun
    • Journal of the Korean Society of Child Welfare
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    • no.59
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    • pp.115-150
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    • 2017
  • The purpose of this study was to examine the current status of the Dream Start program from the perspective of social investment strategy, and as well as to suggest future directions. The program has become a major government welfare program in korea since it was introduced in 2007 as a demonstration project, following research evidence and a sound rationale about the extensive success of Head Start in the U.S. and Sure Start Programme in the UK. The aim of Dream Start is to provide integrated services for the vulnerable children, aged 0 to 12, and their families who are identified using a national administration data record of disadvantaged families with children. In order to promote the vulnerable child's well-being, to overcome inequalities, and to give every child the best start in life, Dream Start adopted a local, "whole family" approach. Case management services form an essential part of the Dream Start to customize and integrate comprehensive services such as counseling, health care, parenting advice and education, academic tutoring, and after-school activities. Although there has been a general improvement in key factors since its inception, Dream Start has not yet sufficiently shown the strong and hoped-for impact. In the meantime, Dream Start must be given financial expansion and extensive policy supports to get the chance of realizing and evaluating long-term gains for children and their families. More work need to be done to overcome inequalities and to make Dream Start service more accessible for the most disadvantaged families with children in Korea. Practical and policy suggestions for future directions of the Dream Start programs were discussed.

A Study on Conservation and Manufacturing Techniques of a Seated Avalokiteshvara with a Thousand Hands of Goryeo Dynasty (고려시대 금동제십일면천수관음보살좌상의 보존처리 및 제작기술 연구)

  • Gwak, Hong In;Kwon, Mi Hye
    • Journal of Conservation Science
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    • v.35 no.3
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    • pp.253-258
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    • 2019
  • The gilt bronze statue, Seated Avalokiteshvara with a Thousand Hands, of the Goryeo dynasty, is the only one in Korea of its kind that has undergone a conservation process for the special exhibition entitled GORYEO: The Glory of Korea. For the conservation treatment, first, a component analysis (XRF) was conducted, and a manufacturing technique (CT) was analyzed. The results of the investigation revealed that the statue was alloyed with Cu, Sn, and Pb ternary bronze. Its surface, except for the detached plating layers, was originally plated using the mercury amalgam method. This statue was assembled after separately casting each part of the body, such as the left and right arms and the wrists, including the hands, with objects. In particular, each wrist was cast and fitted with a metal nail to express each object in the hands more precisely. Inside the statue, there were five iron cores: two for the head, one for the left elbow, one for the right flank, and one for the right waist. For the preservative treatment, natural adhesive agents, including vegetable gelatin and glue (20%), were mixed with alcohol to protect the base metal and adhere to the plating layers. Using synthetic resin (CDK 520+SN-sheet) for the damaged parts, the restored parts could be attached and detached to/from the statue. Eventually, the compositional analysis and conservation treatment left the statue in a stable condition and ready for exhibitions and future studies.

A Study for Failure Examples Including with Engine Oil Leakage, Poor Contact by Fin Damage and Vaporizer Inferiority on LPG Automotive (LPG 자동차의 엔진오일누설, 핀 손상에 의한 접촉불량, 베이퍼라이저 내부불량으로 인한 고장사례연구)

  • IL Kwon, Lee;Chang Ho, Kook;Sung Hoon, Ham;Seung Yong, Lee;Jae Gang, Lee;Seung Min, Han; Woo Chan, Hwang;Dae Cheon, Jang;Chang Bae, You;Jeong Ho, Lee
    • Journal of the Korean Institute of Gas
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    • v.26 no.6
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    • pp.24-29
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    • 2022
  • This paper is a purpose to Analyze and study the failure examples for a engine oil leakage of camshaft bearing seal, poor contact by computer connector fin damage and vaporizer inferiority on LPG automotive. The first example, when the researcher disassembled the cylinder head of engine to establish the cause for oil leakage, he confirmed the engine oil leakage by damaged between the engine intake camshaft bearing and seal part. The second example, the connector fin of power source line that control the starting of a car supplied with engine computer. As a result, it found the fact that the engine operation stopped because of cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phe cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phenomenon as thd gas didn't flow the vaporizer by foreign substance deposit. Finally, it supplied a small quantity gas from vaporizer to mix. As the computer controlling mix opening condition supplied a air as opening signal, the air and fuel became rarefied state. it knew that the engine didn't produce prpper power. Therefore, a car have to throughtly inspect not in order to arise the failure symptoms.

Development of Screw-Type Handy Earth Auger for an Improved Digging Efficiency(I) - Design and Manufacture - (토양굴취력이 향상된 스크류형 경량 식혈기 개발(I) - 설계 및 제작 -)

  • Kim, Jin Hyun;Lee, Jae Hyun;Kim, Ki Dong;Ko, Chi Woong;Kim, Dong Geun
    • Journal of agriculture & life science
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    • v.50 no.3
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    • pp.31-41
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    • 2016
  • This study was conducted to develop a handy earth auger for use in sloppy and rugged forest terrains in order to reduce labor cost which comprises a major part of the production costs in forest afforestation projects. The first prototype is developed consist of two parts, the soil-digging screw and the battery power source. The specifications of the first prototype screw are: length of 170mm, a top diameter of 60mm, bottom diameter of 47mm, 23° angle for each helix, and a 50mm awl-head tip. The use of a single line of screw was selected for reduced weight. In addition, a power source of rotary DC Motor(WD-6G2425, WONILL, Korea) with a maximum torque of 30kgf-cm, rotation of 20-30rpm, K6G30C decelerator with a reduction ratio of 30:1 which could be used with no load for 48 was operated. In consideration of its weight, a lithium battery was utilized in line with the goal of developing a lightweight auger. In order to evaluate the performance of the first prototype, test sites were selected as 6 areas. The rotational force was found to be highest in area A(Solid area), followed by areas F(Mounted slope 40° area) and E(Mounted slope 30° area). It was also observed that in general, the rotational force increased along with the increase in soil depth with the maximum rotational force recorded at 10cm.

3D Face Dimensions and New Fit Test Panels for the Labor Population Using Respirators in South Korea (호흡보호구 사용 노동인구의 3차원 얼굴사이즈 특징 및 한국형 밀착도 검사 패널 개발)

  • Jung-Keun Park;Se-Dong Kim;Hyoun-Min Cho
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.33 no.2
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    • pp.247-264
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    • 2023
  • Objectives: The study was to examine the features of three-dimensional(3D) face dimensions and to develop fit test panels for the labor population using respirators in South Korea. Methods: This study was part of the first-year work of a two-year-project conducted at Occupational Safety and Health Research Institute in 2021. After 3D head dimensions data were collected from Size Korea Center managing Sixth Size Korea databases, 3D face dimensions DB for the South Korean labor population was established for 21 items of face dimensions in line with the ISO/TS 16976-2 and KS A ISO 15535. With the South Korean labor population 3D face dimensions DB, in accordance with the ISO/TS 16976-2, the descriptive statistics of 3D face dimensions were calculated and two fit test panels were developed. Results: A total of 2,752 subjects were finally determined and they were 52.9% for male, 41.2% for the highest age-group of 15-29, and residents in the capital area. Mean and standard deviation were obtained for each of the 21 3D face dimensions items for the South Korean labor population. Among the items, male and female face widths were 137.6±5.7 mm, 133.2±5.0 mm, respectively. Male and female face lengths were 116.6±7.0 mm, 107.8±6.8 mm, respectively. Two new South Korean fit test panels, a bivariate test panel and a principal component analysis test panel, were developed using the 3D face dimensions DB as well. Conclusions: Using the 3D face dimensions DB, the mean and standard deviation were featured for each of the 21 items and also the two fit test panels were newly developed in the study. It is suggested that the study outputs should be utilized practically and effectively in selection, use, and management of respirators at work, expecting that respiratory protection can be furthermore improved for respirator users including labor population across the country.

Conservation Treatment of Jangbogwan from the Joseon Dynasty (조선시대 장보관(章甫冠)의 보존처리)

  • Lee Hyelin;Park Seungwon
    • Conservation Science in Museum
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    • v.30
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    • pp.1-22
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    • 2023
  • This study aims to document the conservation treatment of the fine-hemp official headgear housed by the National Museum of Korea, and to reconsider its existing name following the restoration of the original form of the damaged cultural heritage asset. The headgear consists of a single inner frame with a vertical line at the front, a single outer frame surrounding the inner frame, and a double-layered headband that spans the circumference of the wearer's head and joins the inner and the outer frames. This study applied a conservation treatment to the men's undyed hemp headgear of the Joseon Dynasty in order to remove contaminants and foreign substances on the surface and repair the partially deteriorated and damaged fabric, thereby restoring and stabilizing the original shape and preparing it for exhibitions. The hemp headgear was sewed both by hand and with a sewing machine. Although its overall composition and style are similar to the same type of official headgear from the Joseon Dynasty, the use of a sewing machine supports the assumption that it was produced in the early 1900s. This study identified similarities between the overall composition and shape of the fully-preserved hemp official headgear and those of the jangbogwan, a type of men's official headgear worn by Confucian scholars as part of their everyday attire, and compared it with the shape of jangbogwan seen in documentary records, illustrations, prior research, and portraits from the Joseon Dynasty, as well as with the characteristics of extant jangbowan artifacts, eventually concluding that it is appropriate to classify and name the headgear as a jangbogwan.

Development of Eggs, Larvae and Juveniles of the Hemibarbus labeo from Wicheon Stream, Nakdonggang-River (낙동강 수계 위천에 서식하는 누치 Hemibarbus labeo의 난발생 및 자치어 형태발달)

  • Jae-Min Park;Kyeong-Ho Han
    • Korean Journal of Ichthyology
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    • v.36 no.1
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    • pp.10-19
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    • 2024
  • This study investigated the early life history of Hemibarbus labeo from in Wicheon, stream Nakdonggang-River, and compared their characteristics with closely related species. In April 2021, egg formation and development of autonomous fish were observed in fertilized eggs collected at four spawning sites. The size of the fertilized egg was 1.93~2.39 (average 2.22±0.15, n=30) mm. The water temperature was 22.2~24.1°C, and the hatching time took 109~115 hours. Newly after hatching, the total length of the yolk-sac larvae was 7.50~8.80 (average 7.99±0.46) mm, and the mouth and anus did not develop and had difficulty in being yolk. 6 days after hatching, the preflexion larvae were fed with a total length of 9.49~10.2 (9.78±0.23, n=30) mm. 10 days after hatching, the flexion larvae was 9.97~11.9 (10.7±0.72, n=30) mm in total length, and the tail of the vertebrae began to bend. 20 days after hatching, the postflexion larvae was 12.6~15.2 (13.9±0.77, n=30) mm in total length, and the tailbone was completely bent to 45°. 29 days after hatching, the total length of the juvenile was 16.9~19.8 (18.1±0.91, n=30) mm, and the number of fins reached an integer with 10 dorsal fins, 9 anal fins, and 7 ventral fins. The distribution of melanophore, such as the head, the center of the body, and the upper part of the fin, was different from that of the allied species during the postflexion larvae period, so the morphological characteristics could be distinguished.

Studies on Dairy Farming Status, Reproductive Efficiencies and Disorders in New Zealand (I) A Survey on Dairy Farming Status and Milk Yield in Palmerston North Area (뉴질랜드 (Palmerston North) 의 낙농 현황과 번식 및 번식장해에 관한 연구(I) Palmerston North 지역의 낙농 현황과 우유 생산량에 관한 조사 연구)

  • 김중계;맥도날드
    • Korean Journal of Animal Reproduction
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    • v.24 no.1
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    • pp.1-18
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    • 2000
  • Eighty dairy farms in Palmers ton North area in New Zealand were surveyed on 1) general characteristics (10 Questions), 2) milk yield and feed supplementary (7 questions), 3) reproductive efficiencies (12 questions) and 4) reproductive disorders (12 questions) by mail questions from February to July, 1998. Among those 4 items from 38 dairy farms (47.5%), especially in items 1) and 2), overall dairy farming situation, supplementary feeding and milk yields were surveyed and analyzed for Korean dairy farmers (especially in Cheju island) to have better understanding or higher economical gains. The results were as follows. 1. In dairy experience, 21 (45%) among 38 dairy farms surveyed were answered that farming less than 15 years, 15~19 year, 20~25 years and over 26 years experience were 3 (7.9%), 7 (18.4%), 6 (15.8%) and 5 (13.2%) which generally showed longer experience compare to Korean dairy farming situation. In survey of labour input and business goal of dairy farming, self-managing farms, sharemilkers, unpaid family manpowering farms, manager running farms, farms with hired worker, farms with part time helper and other type was 21 (55.3%), 10 (26.3%), 2 (3.5%), 3 (5.3%), 18 (31.6%), 2 (3.5%), and 1 (1.8%), respectively. 2. Analyzing pasture and tillable land, pasture according to feeding scale (200, 300 and 400 heads) were 56, 90 and 165.3 ha, and tillable lands were 51, 78 and 165 ha which showed some differences among feeding scale. In recording methods in 38 farms replied, 36 (95%) dairy handbook and 23 (70%) dual methods taking farms were higher than that of 10 (26.3%) computer and 15(39.5%) well-recorder methods. 3. Dairy waste processing facilities in environmental field were almost perfect except of metropolitan area, and so no problem was developed in its control so far. Hence, 26 farm (68.4%) of pond system was higher rather than those in 8 (21.2%) of using as organic manure after storing feces of dairy cattle, 1(2.6%) bunker system and 3 (7.9%) other type farms. 4. In milking facilities, 33 farms (86.9%) of Harringbone types were higher than those in 3 (7.9%) of Walkthrough types, 1 (2.6%) of Rotary system and other types. Although the construction facilities was not enough, this system show the world-leveled dairy country to attempted to elevate economic gains using the advantage of climatic condition. 5. In milking day and yearly yield per head, average 275 milking days and 87 drying days were longer than that of 228 average milking days in New Zealand. Annual total milk yield per head and milk solid (ms) was 3,990 kg and approximately 319 kg. Dairy milk solid (ms) per head, milk yield, fat percentage was 1.2 kg, 15.5 kg and average 4.83% which was much higher than in other country, and milk protein was average 3.75%. 6. In coclusion, Palmerstone North has been a center of dairy farming in New Zealand for the last 21 years. Their dairy farming history is 6~9 year longer than ours and the average number of milking cows per farm is 355, which is much greater than that (35) of Korea. They do not have dairy barn, but only milking parlors. Cows are taken care of by family 0.5 persons), are on a planned calving schedule in spring (93%) and milked for 240~280 days a year, avoiding winter. Cows are dried according to milk yield and body condition score. This management system is quite different from that of Korean dairy farms. Cows are not fed concentrates, relying entirely on pasture forages and the average milk yield per cow is 3,500 kg, which is about 1/2 milk yield of Korean dairy farms. They were bred to produce high fat milk with an average of 4.5%. Their milk production cost is the lowest in the world and the country's economy relies heavily on milk production. We Korean farmers may try to increase farming size, decreasing labor and management costs.

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