• Title/Summary/Keyword: divers

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On-site Investigation and Verification of Effect of the Sea Urchin Removal Devices (전기장 자극을 활용한 성게제거장치의 해상성능 평가)

  • Kim, Dae-Jin;Lee, Jungkwan;Kim, Seonghun;Oh, Wooseok;Oh, Taegeon;Lee, Donggil;Lee, Kyounghoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.6
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    • pp.954-959
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    • 2020
  • This study aimed to verify the effectiveness of rescue apparatus, that can capture crabs using external stimuli such as food and electricity, without relying on divers. In this study, a microcomputer-based controller and an IC-device-based controller were developed, and spot inspection was conducted using 20 modules and 30 sea urchin removal modules. Accordingly, 58, 18, 17, and 74 sea urchins were introduced in the first, second, third and fourth experiments, respectively. The result of evaluating the lure of each removal mechanism, based on the catch per unit effort, with an electrical stimulus was 1.1 (32/10), with a feeding stimulus was 3.4 (100/29), and with electrical and feeding stimuli was 3.5 (35/10).

Study on Properties of Carbon Sheet Molding Compound(C-SMC) according to Resin and Carbon Fiber Ratio (수지 및 탄소섬유 함유량에 따른 C-SMC 복합재료 물성 연구)

  • Seo, Dae-kyung;Yang, Suk-gon;Kim, Ki Young;Park, Min Gee;Park, Dae-gyu;Lee, Eun-ha;Kim, Yong-tae;Bae, Jin-Seok
    • Textile Coloration and Finishing
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    • v.32 no.4
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    • pp.245-254
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    • 2020
  • The sheet molding compound composite has been applied divers section. This paper reports processing of carbon fiber reinforced thermosetting composite with diverse resins and which was composed of chopped carbon fiber (30 ~ 60 wt%). Normally the paste that the viscosity is over 15,000 cps has been used in traditional Sheet molding compound (SMC) machine. In this research, SMC machine was designed to make Carbon-sheet molding compound (C-SMC) prepreg which was composed with low viscosity resin (1,800 ~ 2,500 cps increase up to 10,000 cps after aging). In order to confirm the optimal processing condition. Mechanical strength tests including tensile test, shear test, impact test, flexural strength test were conducted on C-SMC composites. Plus we identified the correlation between the mechanical properties and prepreg processing condition (carbon ratio and applied resin).

Development and Applications of an Optic Oxygen Sensor Datalogger for in situ Dissolved Oxygen Monitoring in Coastal Water (연안 용존산소 현장 모니터링용 산소광센서 데이터로거 개발 및 적용)

  • Jae Seong, Lee;Hyunmin Baek
    • Ocean and Polar Research
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    • v.45 no.2
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    • pp.33-42
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    • 2023
  • Dissolved oxygen (DO) is a crucial parameter for assessing environmental conditions in aquatic ecosystems. However, commercial in situ dataloggers for oxygen optodes can be relatively expensive and limited in their specifications. In this paper, we present a novel design for a DO datalogger system based on the control boards family with RP2040 MCU chipset. Our design includes two types of dataloggers: a simple logging system and a programmable system for sampling rates via magnetic switches underwater for divers. We provide detailed descriptions of the system, including the MicroPython source code and drawings to aid in construction. We also discuss the various applications of our DO datalogger system in monitoring dissolved oxygen concentration in coastal waters and assessing the benthic metabolism of aquatic ecosystems. Our DO datalogger system provides an affordable and flexible option for researchers to accurately monitor DO concentrations in aquatic environments, and thereby improve our understanding of these complex ecosystems.

Analysis of Factors Affecting the Health Behavior of Taxi-drivers (택시운전기사의 건강행위에 영향을 미치는 요인분석)

  • Ko, Ja-Kyung
    • Journal of East-West Nursing Research
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    • v.15 no.2
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    • pp.71-81
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    • 2009
  • Purpose: This study was conducted to find out interrelation of health behavior and related variables to provide basic data for an effective health promotion for the taxi-divers. Methods: 293 male taxi-drivers from 2 cities in Korea participated in this study. The data were collected using questionnaires from April 17th to Jun 3rd, 2006, and analyzed by descriptive statistics, t-test, ANOVA, Pearson correlation, and multiple regression. Results: There were statistically significant differences according to monthly income, past illness or surgery, current disease or medication, frequency of fright on daily driving (FFDD), driving fatigue, working style, social support in health status; current disease or medication, FFDD, driving fatigue, duty shift, social support in health perception; body mass index (BMI), FFDD, driving fatigue, intention of changing job, social support in health behavior. Social support, health status, health perception, and health behavior were significantly correlated with one another. The multiple regression analysis showed that health perception (17.8%), BMI (6.8%), intention of changing job (5.7%), and driving fatigue (4.2%) explained the 34.5% variance of health behavior. And the 22.6% of variance of health perception was explained by social support (12.2%), health status (6.9%), and duty shift (3.2%). Conclusions: To promote the taxi-drivers' health, nursing intervention strategies unique for them should consider health behavior and affecting factors.

Exploring Perception on the Swimming Rating System

  • Hyo Rim KIM;Jae Woong KIM;Myung Seok SEO
    • Journal of Sport and Applied Science
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    • v.7 no.4
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    • pp.1-5
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    • 2023
  • Purpose: The purpose of the study is to analyze the perception of swimming rating system. Research design, data, and methodology: In this study, practitioners and leaders of Korean swimming federation were selected as the subjects of the study to institutionalize the grade of swimming. Data analysis was categorized according to word frequency after coding using the Nvivo 12.0 program, and words were visualized using the word cloud program. PASW/WIN 21.0 was employed to analyze demographic characteristics. Triangular verification and expert meetings were conducted three times to increase the validity of the study. In these meetings, the study excluded subjective interpretation and errors of the researcher. Results: First, as a result of analyzing the perception of practitioners before educational training, 16 words and the total frequency of words was 21 times. Second, as a result of analyzing the perception of practitioners after educational training, 22 words and a total of 25 frequencies were found. Third, as a result of analyzing the leader's perception before educational training, 32 words and the total frequency of words was 63 times. Fourth, as a result of analyzing the leader's perception after educational training, 41 words and a total of 72 frequencies were found. Conclusions: Findings indicated divers feelings and thoughts of practitioners and leaders of Korean swimming federations towards swimming rating system. Further implications were discussed.

Optimum Application Rates of Phosphate and Potassium Fertilizer under Forcing Culture for High-Quality Rhodiola rosea L. Production (바위돌꽃 (Rhodiola rosea L.)의 촉성재배시 인산과 칼리의 적정시비량)

  • Lee, Kang-Soo;Li, Long-Gen;Hwang, Seon-Ah;Cho, Jae-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.6
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    • pp.423-429
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    • 2009
  • Rhodiola rosea L., a traditional medicinal plant in Eastern Asia, is widely used by astronauts, divers and mountaineers to improve their stress resistance. This experiment was conducted to investigate the optimum application rates of phosphate and potassium under the forcing cultivation for high-quality Rhodiola rosea L. production. The application rate of $8kg\; 10a^{-1}$ of phosphate and $30kg\;10a^{-1}$ of potassium showed the highest yield of Rhodiola rosea L. root. There was no significant difference between the application rates of phosphate or potassium fertilizer and the content of salidroside.

The Experimental Study for inferring the Safety-Factor of the Limit of Span-Deflection in Standard Specifications for Highway Bridges for Setting the Standard of the Measurement Criteria in RC Girder (철근콘크리트 거더의 관리기준치 설정을 위한 도로교설계기준 처짐 제한치의 안전계수 추정에 관한 실험적 연구)

  • Joo, Bong-Chul;Park, Ki-Tae;Hwang, Yoon-Koog;Lee, Woo-Sang
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.1 s.53
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    • pp.145-151
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    • 2009
  • The span deflection among the monitoring items of bridge measurement system in real time is representative behaviour and important index of superstructure condition. the limit of span deflection in Standard Specifications for Highway Bridge in Korea has been applied to the method that is making the management-criteria for span deflection in bridge measurement system. But the limit concern mainly serviceability of divers. So it is difficult to find the safety factor of the limit from the viewpoint of bridge safety. This study estimated the safety factor of the limit of span-deflection in Standard Specifications for Highway Bridge in Korea from the viewpoint of bridge safety by the indoor structural test.

Kinematic Analysis of Back Somersault Pike According to Skill Level in Platform Diving

  • Park, Jiho;Yoon, Sukhoon
    • Korean Journal of Applied Biomechanics
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    • v.27 no.3
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    • pp.157-164
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    • 2017
  • Objective: The purpose of this study was to investigate kinematic differences in back pike somersault in platform diving according to skill level and to apply the findings to improve performance. Method: Korean divers participating in this study were divided into a skilled group (age: $21.6{\pm}4.16y$, height: $1.68{\pm}0.03m$, weight: $62.0{\pm}3.94kg$, career: $12.6{\pm}5.13y$) and a less-skilled group (age: $20.6{\pm}2.7y$, height: $1.72{\pm}0.05m$, weight: $64.8{\pm}6.76kg$, career: $12.2{\pm}2.49y$) and an independent t-test was performed to analyze differences between groups at the moment of takeoff. Results: The two groups showed significant differences in displacement and velocity of center of mass (COM), takeoff angle, hip joint angle, knee joint angular velocity, and hip joint angular velocity at the takeoff (p<.05), and significant differences in displacement of COM, hip joint, and ankle joint during flight (p<.05). Conclusion: For a successful back pike, the COM should rise quickly in the vertical direction and the hip joint angle and angular velocity should increase. To improve performance, the back pike turn should be practiced on the ground before an attempt on a 10-m platform, to stretch the ankle and knee joints and enable quick flexion of the hip joint when turning in flight.

The Development of Digital Contents Based on Jeiu Haenyeo's Anti-Japan Resistance (제주해녀항일운동 기반 디지털 콘텐츠 개발)

  • Jo, Eun-Hee;Lim, Ji-Young;Hahn, Eun-Mi;Yang, Hye-Sun;Bae, In-Suk;Hong, Yoon-Ji;Yoon, Mi-Hye;Kim, Seong-Baeg;Kim, Dong-Jun
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.168-171
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    • 2006
  • The Haenyeo of Jeju exists as a unique human resource only in Korea and Japan in the world. Especially, the anti-Japan opposition movement of the Haenyeo of Jeju, which had started to get the right to live on their own in 1931, had developed as the national liberation movement by struggling against a colonial of Japan and the official regulation association that was a plundering organization of Japan. Accordingly, there is making an effort to register Jeju's women divers as The National Treasure in UNESCO's Memory of the world. In this research, we are going to make stuff like a digital storytelling, characters, animation movies, games, and hompage to let our children understand and succeed the spirit and culture of the Haenyeo. We'll also use these contents for the education. We examine ways to recreate the culture resources related to the Haenyeo who gradually vanishes.

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A Kinematical Analysis of 205B Motion in Platform Diving (플랫폼 다이빙 종목 205B동작의 운동학적 분석)

  • Lee, Chong-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.53-62
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    • 2008
  • The purpose of this research was to analyze the kinematics of the 205B movement in platform diving. For the experiment, 2 athlete from the national diving team were chosen as the subject and two S -VHS video cameras were used. For this diving players preparing for the olympics participated. It was shown that the mean total took $1.112{\pm}0.12s$. In order to perform better, the divers time must be increased, at take off and rotation must be done high up and the horizontal distance must be shorted to main entrance of the water. To enter the water safely, the jump has to be high, the horizontal speed slow and the vertical speed as fast as possible. At E1 the lower limbs change in speed should decrease and after the rotation begins at E2. At take off, the jump is more important than the rotation for the performance of the dive. At take off, the trunk angular velocity was high, and this was needed to jump high for moment of inertia for rotation because for efficient jumping the upper body has to spread out and increase the height of the center of mass.