• Title/Summary/Keyword: stand-off

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Reflecting on the History and Future of Republic of Korea Navy (대한민국 해군창설 : 회고와 당부)

  • Hahm, Myung-Soo
    • Strategy21
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    • s.37
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    • pp.5-31
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    • 2015
  • The Republic of Korean Navy (ROKN) started from scratch. However, ROKN demonstrated its Blue Navy capabilities successfully to the entire world by conducting "Operation Early Dawn" at the Aden Bay, Yemen in Jan 2011. On the event of the 70th anniversary of the ROKN, I would like to retrospect past gleaning from voyages and challenges we had in the past. At the very inception of the ROKN, Korean government as well as senior military leaders recognized that it had no time to spare to clean up military those were insinuated deeply by communist agents. It was the top priority of the government. The Mongumpo Operation which was not well known, conducted by ROKN was one of the clean-up drive. The Korean War sometimes called as "a fire from land put-off at the sea". The world famous "Incheon Landing" which reversed war situation from the Nakdong Perimeter also done by Sea Power. ROKN conducted various maritime operations including not only Incheon Landing, but amphibious operation at Hungnam, mine sweeping, sea convoy, Wonsan Withdrawal. On the same day of the Korean War started, 25th June 1950, unless the victory of the ROKNS Baekdusan (PC 701) at the Korean Strait, the waning lamp light of Korea could not be rekindled by the participation of the U.N. The ROKN rescued the 17th regiment of Korean Army from the isolation at the Ongjin Peninsular and transported gold and silver bars stored at the Bank of Korea to the Navy supply deposit in Jinhae safely. ROKN special intelligence unit conducted critical HUMINT which led Incheon Landing success. One of important mission ROKN conducted successfully was not only transporting war fighting materials but also U.S. provided grains to starving Koreans. ROKN participated Vietnam campaign from 1960s and conducted numerous maritime transportation operations supplying materials to Vietnam military forces along the long coastal lines. Experienced Naval Officers and enlisted men who discharged and acquired as merchant marine certificate supported most of the U.S. sea lift operations throughout the Vietnam campaign. ROK-US Combined Forces which had been honed and improved its war fighting capabilities through the Korean War and out of Vietnam jungle playing key deterrent against threat from north Korea. However, those threat level will be completely different when north Korea finish its nuclear weapon ambition. In order to stand firm against north Korean nuclear threat, I would like to expect strong political leadership supporting nuclear submarine for ROKN.

The Forecasting a Maximum Barbell Weight of Snatch Technique in Weightlifting (역도 인상동작 성공 시 최대 바벨무게 예측)

  • Hah, Chong-Ku;Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.15 no.3
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    • pp.143-152
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    • 2005
  • The purpose of this study was to predict the failure or success of the Snatch-lifting trial as a consequence of the stand-up phase simulated in Kane's equation of motion that was effective for the dynamic analysis of multi-segment. This experiment was a case study in which one male athlete (age: 23yrs, height: 154.4cm, weight: 64.5kg) from K University was selected The system of a simulation included a multi-segment system that had one degree of freedom and one generalized coordinate for the shank segment angle. The reference frame was fixed by the Nonlinear Trans formation (NLT) method in order to set up a fixed Cartesian coordinate system in space. A weightlifter lifted a 90kg-barbell that was 75% of subject's maximum lifting capability (120kg). For this study, six cameras (Qualisys Proreflex MCU240s) and two force-plates (Kistler 9286AAs) were used for collecting data. The motion tracks of 11 land markers were attached on the major joints of the body and barbell. The sampling rates of cameras and force-plates were set up 100Hz and 1000Hz, respectively. Data were processed via the Qualisys Track manager (QTM) software. Landmark positions and force-plate amplitudes were simultaneously integrated by Qualisys system The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 9Hz calculated with Andrew & Yu's formula. The input data of the model were derived from experimental data processed in Matlab6.5 and the solution of a model made in Kane's method was solved in Matematica5.0. The conclusions were as follows; 1. The torque motor of the shank with 246Nm from this experiment could lift a maximum barbell weight (158.98kg) which was about 246 times as much as subject's body weight (64.5kg). 2. The torque motor with 166.5 Nm, simulated by angular displacement of the shank matched to the experimental result, could lift a maximum barbell weight (90kg) which was about 1.4 times as much as subject's body weight (64.5kg). 3. Comparing subject's maximum barbell weight (120kg) with a modeling maximum barbell weight (155.51kg) and with an experimental maximum barbell weight (90kg), the differences between these were about +35.7kg and -30kg. These results strongly suggest that if the maximum barbell weight is decided, coaches will be able to provide further knowledge and information to weightlifters for the performance improvement and then prevent injuries from training of weightlifters. It hopes to apply Kane's method to other sports skill as well as weightlifting to simulate its motion in the future study.

A Study on Design of Wind Blade with Rated Capacity of 50kW (50kW 풍력블레이드 설계에 관한 연구)

  • Kim, Sang-Man;Moon, Chae-Joo;Jung, Gweon-Sung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.3
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    • pp.485-492
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    • 2021
  • The wind turbines with a rated capacity of 50kW or less are generally considered as small class. Small wind turbines are an attractive alternative for off-grid power system and electric home appliances, both as stand-alone application and in combination with other energy technologies such as energy storage system, photovoltaic, small hydro or diesel engines. The research objective is to develop the 50kW scale wind turbine blades in ways that resemble as closely as possible with the construction and methods of utility scale turbine blade manufacturing. The mold process based on wooden form is employed to create a hollow, multi-piece, lightweight design using carbon fiber and fiberglass with an epoxy based resin. A hand layup prototyping method is developed using high density foam molds that allows short cycle time between design iterations of aerodynamic platforms. A production process of five blades is manufactured and key components of the blade are tested by IEC 61400-23 to verify the appropriateness of the design. Also, wind system with developed blades is tested by IEC 61400-12 to verify the performance characteristics. The results of blade and turbine system test showed the available design conditions for commercial operation.

A Seismic Study on Muddy Sediment Deposits in the Northern Shelf of the East China Sea (동중국해 북부대륙붕에 발달한 니질 퇴적체의 탄성파 연구)

  • Choi Dong-Lim;Lee Tae-Hee;Yoo Hae-Soo;Lim Dhong-Il;Huh Sik;Kim Kwang-Hee
    • Economic and Environmental Geology
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    • v.38 no.6 s.175
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    • pp.633-642
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    • 2005
  • We present the sedimentary sequence and distribution pattern of the late Holocene muddy deposits in the northern East China Sea shelf using the high-resolution 'Chirp' profiles. The seismic sedimentary sequence overlying acoustic basement (basal reflector-B) can be divided into two depositional units (Unit 1 and 2) bounded by erosional bounding surface (mid reflector-M). The lower Unit 1 above basal reflector-H is characterized by the acoustically parallel to subparallel reflections and channel-fill facies. The upper Unit 2, up to 7 m in thickness, shows seismically semi-transparent seismic facies and lenticular body form. On the base of sequence stratigraphic concept, these two sediment units have developed during transgression and highstand period, respectively, since the last sea-level lowstand. The transgressive systems tract (Unit 1) lie directly on the sequence boundary (reflector B) that have farmed during the last glacial maximum. The transgressive systems tract in this study consists mostly of complex of delta, fluvial, and tidal deposits within the incised valley estuary system. The maximum flooding surface (reflector M) corresponding to the top surface of transgressive systems tract is obviously characterized by erosional depression. The highstand systems tract (Unit 2) above maximum flooding surface is made up of the mud patch filled with the erosional depression. The high-stand mud deposits showing a circle shape just like a typhoon symbol locates about 140 km off the south of Cheju Island with water depth of $60\~90m$. Coverage area and total sediment volume of the mud deposits are about $3,200km^2$ and $10.7\times10^9\;m^3$, respectively. The origin of the mud patch is interpreted as a result of accumulating suspended sediments derived from the paleo-Yellow and/or Yangtze Rivers. The circular distribution pattern of the mud patch appears to be largely controlled by the presence of cyclonic eddy in the northern East China Sea.

A Study on the Changing Perception of Queen Mother of the West from the Perspective of Yin-Yang Theory (음양론 관점에서 본 서왕모(西王母) 인식 변화 고찰)

  • Jo Min-hwan
    • Journal of the Daesoon Academy of Sciences
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    • v.42
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    • pp.45-73
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    • 2022
  • The phenomenon of veneration for Queen Mother of the West [西王母 Chn: Xiwangmu Kr: Seowangmo] is a 'cultural flow' that has garnered great interest not only in China but also in Korea for many years. To properly understand the cultural trend regarding the Queen Mother of the West, it is essential to view the related mythology as it corresponds to East Asian women as well as the transformation of society's view of women. In addition to the outcomes that result from the establishment of a patriarchal society, the relationship between goddesses and gods gradually becomes a relationship of discrimination based upon differences. Accordingly, as women change into objects that are given meaning rather than subjects that give meaning, the de-sacredization of the goddess occurs. This paper focused on the changes in the perception of the Queen Mother of the West from the view of Yin-Yang theory. This approach shows a transition process of transforming wherein she has morphed into an assistant or spouse of a god as part of a trend that deemphasizes the divinity of her as a stand-alone goddess. Yin-Yang theory is the key to understanding culture, history, and art as well as Chinese philosophy. This key can be further applied to the theme of women in mythology. What is particularly noteworthy about the process by which the Queen Mother of the West was defined as a goddess is that she was original described as half-human and half-beast and yet by the time her depictions became fully human and fully woman, she was described instead as an absolute beauty endowed with great artistic talent. In this paper, it will be revealed that the perception of the Queen Mother of the West, as an absolute beauty and artistic talent, is embedded with the male societal desire for an image of the feminine as understood via Yin-Yang theory. Queen Mother of the West as she was depicted in the Classic of Mountains and Seas (山海經 Chn: Shanhaijing Kr: Sanhaegyeong) had a half-human half-beast form that instilled people with fear of disasters and punishments from heaven. However, in the Han Dynasty, her religious significance became that of an object to ward off evil and attain blessings. By the time of the novel, Tales of the Strange (志怪小說 Chn: Zhiguaixiaoshuo Kr: Jigoesoseol), from the Wei, Jin, Southern and Northern Dynasties, she was transformed into a goddess in the image of beautiful woman in charge longevity and immortality. From the perspective of Yin-Yang theory, the changes in the perception of Queen Mother of the West was found to contain the following meaning: as an extension of the establishment of a patriarchal system and subordinate laws, her new form was made to be pleasing to the male gaze and Yin-Yang theory was brought in to support those changes later.