• Title/Summary/Keyword: 반동방식

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Analysis of Isolation System for Impulsive Force Device with Recoil Mechanism (반동방식 충격기구의 완충시스템 해석)

  • Kim, HyoJun;Ryu, BongJo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.3 s.96
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    • pp.272-279
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    • 2005
  • In this study the optimal isolation system for the prototype HIFD(high impulsive force device) is investigated. For this purpose, firstly, the dynamic behavior of a human body and a transmitted force under specific operation conditions are analyzed through a series of experimental works using the devised test setup. In order to design the optimal dynamic absorbing system, the parameter optimization process is performed using the simplified isolation system model based on the experimental results of linear impulse and transmitted force. Finally, under the parameters satisfying the constraints of the buffering displacement and the transmitted force, the performance of the designed isolation system for the prototype HIFD is evaluated by experiment.

Change in Countermovement Jump Strategy by Varying Jump Height Based on Simplified Framework for Center of Mass Mechanics (반동을 이용한 수직 점프 시 높이 변화에 따른 운동역학 및 상변화 시점에서의 지면반력 벡터 변화)

  • Kim, Seyoung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.4
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    • pp.277-283
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    • 2017
  • In this study, we investigated how a jumping strategy changes with an increase in the vertical jump height for a resultant ground reaction force (GRF) vector. We expected that the resultant force vector between two sequential motion phases (i.e., countermovement and push-off) of the countermovement jump would significantly change with the vertical jump height to take advantage of the resulting supportive force (i.e., an initial push-off force larger than the body weight) through the countermovement phase. Nine healthy young subjects were instructed to jump straight up to five different height levels ranging from 191 cm to 221 cm, and the kinematic and kinetic data were obtained in regular trials. The results showed that a lower center of mass position and larger resultant force vector were clearly observed in a higher jump, implying that the countermovement strategy changed with the vertical jump height to prepare for sufficient joint deviation and obtain a force advantage for larger push-off work.

Coherent and Semi-Coherent Correlation Detection of DSSS-FSK Signals for Low-Power/Low-Cost Wireless Communication (저전력, 저가격 무선통신을 위한 DSSS-FSK 신호의 동기 및 반동기 상관 검파)

  • Park Hyung Chul
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.4 s.334
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    • pp.1-6
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    • 2005
  • For the low power and low cost transceivers, direct sequence spread spec01m frequency-shift keying (DSSS-FSK) is proposed. A transmitter of the DSSS-FSK signal can be implemented by a simple direct modulation using the phase locked loop. Since the DSSS-FSK signal has negligible power around the carrier frequency, low cost direct conversion receiver can be used. Optimum coherent and semi-coherent correlation detection methods for the DSSS-FSK signal are proposed and analyzed. Segmented semi-coherent correlation detection method is proposed to improve the bit error rate performance in the large carrier frequency offset.

A Study on the Decompression Performance by the Orifice Diameter (오리피스의 직경에 따른 감압성능에 관한 연구)

  • Park, Bong-Rae;Yun, Ki-Jo;Jang, Kyeong-Nam;Choi, Jung-Ung;Baek, Eun-Sun
    • Fire Science and Engineering
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    • v.26 no.6
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    • pp.57-63
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    • 2012
  • The modern trend for high-rise buildings makes the application of fire protection systems difficult and the current systems have a limitation to provide appropriate functions. Indoor hydrant systems are fire suppression systems installed in most buildings that require valves, hoses, and nozzles to be manually operated in the event of a fire. Therefore, high discharge pressure can cause difficulty in the operation of indoor fire hydrant systems and damage to hoses due to a high reaction force. To prevent these problems, the pressure is reduced and decompression valves are commonly installed at angle valves which are the discharge points of indoor hydrants. In the case of high-rise buildings, however, there are cases where stable operation is difficult even with the installation of decompression valves. To verify this, we have measured the decompression performance by the orifice diameter and calculated the reaction force. Results of the study showed that decompression valves need to be produced in different sizes to provide stable decompression where high pressure is required as in high-rise buildings.

Clinical Features of Acute Nonspecific Mesenteric Lymphadenitis and Factors for Differential Diagnosis with Acute Appendicitis (급성 비특이성 장간막 림프절염의 임상 소견과 급성 충수돌기염과의 감별 인자)

  • Shin, Kyung Hwa;Kim, Gab Cheol;Lee, Jung Kwon;Lee, Young Hwan;Kam, Sin;Hwang, Jin Bok
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.7 no.1
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    • pp.31-39
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    • 2004
  • Purpose: Although acute nonspecific mesenteric lymphadenitis (ANML) is probably common cause of abdominal pain in children, which can be severe enough to be an abdominal emergency, the clinical features of mesenteric lymphadenitis are not clear. Also, a differential diagnosis with acute appendicitis (APPE) is indispensable to avoid serious complications. The clinical features of ANML were determined, and the risk factors for differential diagnosis with APPE were analyzed. Methods: Between November 2000 and May 2001, data from 26 patients (aged 1 to 11 years) with ANML and 21 patients (aged 2 to 13 years) with APPE were reviewed. ANML was defined as a cluster of five or more lymph nodes measuring 10 mm or greater in their longitudinal diameter in the right lower quadrant (RLQ) without an identifiable specific inflammatory process on the ultrasonographic examination. There were risk factors on patient's history, physical examination, and laboratory examination; the location of abdominal pain, abdominal rigidity, rebound tenderness, fever, nocturnal pain, the vomiting intensity, the diarrhea intensity, the symptom duration, and the peripheral blood leukocytes count. Results: Of the 26 ANML patients and 21 APPE patients, abdominal pain was noted on periumbilical (76.9% vs 14.2%), on RLQ (11.5% vs 71.4%), with abdomen rigidity (7.6% vs 80.9%), with rebound tenderness (0.0% vs 76.1%)(p<0.05), in the lower abdomen (11.5% vs 14.2%), and at night (80.8% vs 100.0%) (p>0.05). The clinical symptoms were vomiting (38.4% vs 90.4%), the vomiting intensity ($1.5{\pm}0.7$ [1~3]/day vs $4.5{\pm}2.9$ [1~10]/day), diarrhea (65.3% vs 28.5%) (p<0.05), and fever (61.5% vs 76.2%)(p>0.05). The period to the subsidence of abdominal pain in the ANMA patients was $2.5{\pm}0.5$ (2~3) days. The laboratory data showed a significant difference in the peripheral blood leukocytes count ($8,403{\pm}1,737[5,900{\sim}12,300]/mm^3\;vs\;15,471{\pm}3,749[5,400{\sim}20,800]/mm^3$)(p<0.05). Discriminant analysis between ANML and APPE showed that the independent discriminant factors were a vomiting intensity and the peripheral blood leukocytes count and the discriminant power was 95.7%. Conclusion: The clinical characteristics of ANML were abrupt onset of periumbilical pain without rigidity or rebound tenderness, a mild vomiting intensity, normal peripheral leukocytes count, and relatively short clinical course. If the abdominal pain persist for more than 3 days, and/or the vomiting intensity is more than 3 times/day, and/or the peripheral leukocytes count is over $13,500/mm^3$, abdominal ultrasonography is recommended to rule out APPE.

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Studies on the Directivity of Gokjungkyeong(Kyung Overlapped with Gok) which was specified in Byeokgye-ri, Yangpyeong-gun and the Hwaseo Lee, Hang-ro's Management in Byeokwon Garden (양평 벽계리에 설정된 곡중경(曲中景)의 지향성과 화서(華西) 이항로(李恒老)의 벽원(蘗園) 경영)

  • Jung, Woo-Jin;Rho, Jae-Hyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.3
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    • pp.78-97
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    • 2016
  • The objectives of this study are to examine the context of the establishment of Suhoe Gugok, Byeokgye Gugok Vally, and Nosan Palkyung, which have been established in Seojong-myeon of Yangpyeong-gun, by literature review and site investigations, and to determine the sceneries of Byeokgye scenic site as enjoyed and managed during the period of Hwaseo Lee, Hang-ro(華西 李恒老). The results of the study are as follows. First, Byeokgye Gugok Vally(黃蘗九曲) and Nosan Palkyung(蘆山八景), which have been established after the period of Hwaseo and theorized to have been established around key scenic areas associated with Hwaseo's activities, the analysis results showed that they were collecting sceneries of modern times. The extensive overlap between Byeokgye Gugok Vally and concentrated scenic elements of Suhoe Gugok(水回九曲), and the artificial configuration from the end point of Suhoe Gugok to the beginning point of Nosan Palkyung, reveal the pattern of space conflict and hegemony between Byeokgyes of Suip-ri and Nomun-ri. This is likely to be caused by the conflict between the historicity of the group that enjoyed Byeokgye prior to Hwaso's period and the strong territoriality of the space filled with the image of Hwaseo. Second, Byeokgye Gugok Vally was the secondary spatial system created by selecting the most scenic sites in Suip-ri while expanding the area of Nosan Palkyung. After establishment of Byeokgye Gugok Vally, the spatial identity of the entire Byeokgyecheon area was effectively established. This was a "Hwaseo-oriented" move, including the complete exclusion of the scenic sites from the pre-Hwaseo period such as Cheongseo Gujang and Suhoe Gugok's Letters Carved on the Rock. Consequently, the entire Byeokgyecheon area was reorganized into a cultural scenic site with Heoseo's influence. Third, Fifth, creations of Gugok(九曲) to determine the lineage of the Hwaseo School from Juja(朱子) to Yulgok(栗谷) to Uam(尤庵) to Hwaseo is likely to be an opportunity of birth and external motivation of the establishment of new Gugok Palkyung. In other words, Nosan Palkyung and Byeokgye Gugok Vally are likely to have been created as a reaction to the change of the center of the Hwaseo School to Okgyedong, and with strategic orientation based on the motivation and needs such as creation of the connecting space between Mui Gugok, Gosan Gugok, and Okgye Gugok, and the elevation of Hwaseo's status. Fourth, from the Hwaseo's Li-centric point of view, all revered sites in Beokwon(蘗園) that he managed existed as the spatial creative work to experience the existence of "li" through the objects in the landscape and the boundary of the spirit of emptiness of the aesthetic self. This clearly shows how Byeokgye Gugok Vally or Nosan Palkyung must be defined, and furthermore, appreciated and approached, prior to discussing it as the space associated with Hwaseo. Fifth, Nosan Palkyung was composed of cultural scenic landscapes of Gokjungkyung(曲中景) with eight scenic sites where Hwaseo gave his teachings and spend time around, in the Byeokgye of Nomun-ri area of Byeokgye Gugok Vally. The sceneries is, however, collected by depending on Hwaseo's Letters Carved on the Rock and poetry. Consequently, an inner exuberance of Nosan Palkyung is satisfied beside Byeokgye Gugok Vally, but its conceptual adequacy leaves room for questions.

Hwaunsi(和韻詩) on the Poems of Tu Fu(杜甫) and Su Shi(蘇軾) Written by Simjae(深齋) Cho Geung-seop(曺兢燮) in the Turning Point of Modern Era (근대 전환기 심재 조긍섭의 두(杜)·소시(蘇詩) 화운시)

  • Kim, Bo-kyeong
    • (The)Study of the Eastern Classic
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    • no.56
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    • pp.35-73
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    • 2014
  • This paper examined the poem world of Simjae(深齋) Cho Geung-seop(曺兢燮: 1873-1933) in the turning point of the modern era, focused on his Hwaunsi (和韻詩: Poems written by using the rhymes of other poets' poems). In his poems, there are lots of Hwaunsi on the poems of Tu Fu(杜甫) and Su Shi(蘇軾), especially. This makes him regarded as a medieval poet, engaged in Chinese poem creation in the most traditional method in the turbulent period. Looking at the Hawunsi(和韻詩) alone, Simjae's creative life became the starting point of turnaround at around 40 years old. Before the age of 40, the poets in the Tang Dynasty and Song Dynasty and Ming Dynasty and Qing Dynasty and Korean figures like Lee Hwang(李滉), as well as Tu Fu and Su Shi were the subjects of his Hwanunsi. After the age of 40, some examples of writing poems using the rhymes of other poets' poems, especially Korean figures related to regions, are often found, reducing Hwaunsi on Tu Fu and Su Shi. Simjae called Tu Fu the integration of poets, talking about the integrity of poetic talent and his being highly proficient in mood and view. As reflecting such an awareness, the themes and moods and views are demonstrated diversely in Simjae's Hwaunsi. Although, he did not reveal his thinking about the poems of Su Shi, he seemed to love Su Shi's poems to some degree. The closeness to the original poems, the poems of Tu Fu are relatively higher than those of Su Shi. Roughly speaking, Simjae tried to find his own individuality, intending to follow Tu Fu, but, he seemed to attempt to reveal his intention using Su Shi's poems, rather than trying to imitate. To carefully examine, Simjae wrote Hwaunsi, but he did not just imitate, but revealed the aesthetics of comparison and difference. In many cases, he made new meanings by implanting his intentions in the poems, while sharing the opportunity of creation, rather than bringing the theme and mood and view as they are. The Hwaunsi on Su Shi's poems reveal the closeness to the original poems relatively less. This can be the trace of an effort to make his own theme and individuality, not being dominated by the Hwaun(和韻: using the rhymes of other poets' poems) entirely, as he used the creative method having many restrictions. However, it is noted that the Hwaunsi on Tu Fu's poems was not written much, after the age of 40. Is this the reason why he realized literary reality that he could not cope with anymore with only his effort within the Hwaunsi? For example, he wrote four poems by borrowing Su Shi's Okjungsi(獄中詩: poem written in jail) rhymes and also wrote Gujung Japje(拘中雜題), in 1919, while he was detained. In these poems, his complex contemplation and emotion, not restricted by any poet's rhymes, are revealed diversely. Simjae's Hwaunsi testifies the reality, in which Chinese poetry's habitus existed and the impressive existence mode at the turning point of the modern era. Although, the creation of Hwaunsi reflects his disposition of liking the old things, it is judged that his psychology, resisting modern characters' change, affected to some degree in the hidden side. In this regard, Simaje's Hwaunsi encounters limitation on its own, however, it has significance in that some hidden facts were revealed in the modern Chinese poetry history, which was captured with attention under the name of novelty, eccentricity and modernity.