한국 수구 국가대표와 상비군 선수의 체력요인 비교

Yuezhu Zhou,김창선,이승재,민석기 한국운동생리학회 2023 운동과학 Vol.32 No.1

PURPOSE: The purpose of the study was to evaluate isokinetic muscle strength (IMS), anaerobic power, basic physical fitness, and body composition of Korean water polo athletes in the national team (NT) and reserve team (RT). METHODS: Twenty-nine male water polo athletes (aged 22.2±1.9 years) including 14 NT and 15 RT athletes participated in this study. The participants were evaluated for physiological parameters such as body composition, physical fitness, IMS, and anaerobic power. The IMS of the knees and shoulders (60°/s, 180°/s, and 240°/s, indicating maximal muscle strength, muscle power, and muscle endurance, respectively) and trunk (30°/s and 120°/s) were measured using a dynamometer (NORM, CSMI, USA). Anaerobic parameters were also measured using the 30-s maximal ergometer cycling Wingate test (Monark, Sweden). RESULTS: No significant differences in the IMS of the knee were found between two groups. Although the IMSs of shoulder flexion at 180o/s and 60°/s were not significantly different between the two groups, the IMSs of shoulder extension at 180o/sec and 60°/s in NT athletes were higher than those in RT athletes (p<.05, p<.01). There were no significant differences between the NT and RT (NS) groups in the left and right knee flexion/extension ratios (H/Q ratio, 60o/sec, 180o/sec). However, a significant difference was found in the right shoulder extension/flexion ratio (E/F ratio) between the two groups. Although height, muscle mass, fat mass, and Wingate anaerobic power were not significantly different between the two groups, the FEV1 and FVC of NT athletes were higher than those of RT athletes, respectively (p<.05, p<.01). CONCLUSIONS: These results suggest the athletic characteristics of water polo players who pass and shoot and make swimming movements. The difference in the shoulder extensor muscle strength was one of the determining factors for the performance of water polo athletes.

Half mJ Supercontinuum Generation in a Telecommunication Multimode Fiber by a Q-switched Tm, Ho:YVO4 Laser

Renlai Zhou,Jiancun Ren,Shuli Lou,Youlun Ju,Yuezhu Wang 한국광학회 2015 Current Optics and Photonics Vol.19 No.1

Up to ~520 μJ broadband mid-infrared (IR) supercontinuum (SC) generation in telecommunicationmultimode fiber (MMF) directly pumped by a 2.054 μm nanosecond Q-switched Tm,Ho:YVO4 laser isdemonstrated. An average output power of 3.64 W is obtained in the band of ~1900 to ~2600 nm, andthe corresponding optic-to-optic conversion efficiency is 67% by considering the coupling efficiency. Thespectrum has extremely high flatness with negligible intensity variation (<2%) in the wavelength intervalof ~2070 to ~2475 nm. The SC long-wavelength edge is limited by the silicon glass material loss, andby optimizing the MMF length, the SC spectrum could extend out to ∼2.6 μm. The output SC pulseshapes are measured at different output powers, and no splits are found. The SC laser beam is nearlydiffraction limited with an M2 =1.15 in 2.1 μm measured by the traveling knife-edge method, and thelaser beam spot is monitored by an infrared vidicon camera

국궁 활쏘기 동작 시 근활성 분석

김창선 ( Changsun Kim ),( Zhou Yuezhu ),박동호 ( Dong-ho Park ),김기훈 ( Kihoon Kim ),정왕수 ( Wangsoo Jeong ),김혜리 ( Hye-ree Kim ),이기광 ( Kikwang Lee ),민석기 ( Seok-ki Min ) 한국스포츠정책과학원(구 한국스포츠개발원) 2021 체육과학연구 Vol.32 No.1

〔목적〕 양궁종목에서 근전도를 이용한 운동학적 연구는 증가했지만, 우리나라 전통 활쏘기인 국궁 관련 연구는 전무한 실정이다. 본 연구의 목적은 국궁 궁사를 대상으로 활쏘기 동작중의 근전도를 평가하는 것이다. 〔방법〕 대상자는 국궁 궁사 10명으로 활쏘기 자세에 따라 마주 서기 그룹(PSG, n=5)과 사선 서기 그룹(OSG, n=5)의 두 집단으로 구분하였다. 근전도는 준비(Set), 거궁(Set up), 만작(Full draw), 발시(Release), 마치기(Ending) 등 5개 동작의 활쏘기 국면에서 12개의 근육에서 근전도를 측정했다. 〔결과〕 만작 및 발시 시의 뒤어 깨세모근, 등세모근, 큰마름근, 깍지팔의 넓은등근, 위팔두갈래근, 아래팔폄근무리, 위팔세갈래근, 어깨올림근의 근활성은 유의하게 증가하였다가, 마치기 국면에서는 다시 감소했다(p<.01, p<.001). 또한, 척주세움근의 근활성은 만작 및 발시 시 증가(p<.01, p<.001)한 반면, 배곧은근, 넓다리곧은근, 큰볼기근에 있어서는 유의한 변화는 없었다. 마주 서기 집단과 사선 서기 집단을 비교한 결과, 사선 서기 집단의 넓다리곧은근 근활성은 마주 서기 집단의 발시(p<.05) 국면 보다 높았고, 마치기 국면까지 유지되었다(p<.05). 한편, 활의 장력이 높아질수록 발시 시에 깍지 팔의 위팔두갈래근 근활성이 높아졌다(p<.05). 〔결론〕 국궁 활쏘기 시 복부, 다리, 엉덩이 근육보다 양팔과 등 근육이 더 활성화된다는 것이 시사되었다. 또한, 마주 서기 자세시에 상체를 비틀기 위해 하지의 근활성이 억제될 가능성이 있으며, 활의 장력이 높을수록 깍지 팔의 위팔두갈래근 근력 증가가 필요할 것으로 판단된다. [Abstract] The past few decades has seen increasing kinematic studies using surface electoromyography (EMG) in archery, however there has been no such specific study in Korean traditional archery. The purpose of this study was to evaluate EMGs during archery shooting motion in Korean traditional archers. Ten men Korean traditional archers were participated, and divided into two groups according to the shooting stance; parallel stance group(PSG, n=5) and oblique stance group(OSG, n=5). The surface EMGs were measured 12 muscles during shooting motion of five events including Junbi(Set), Geogung(Set up), Manjak(Full draw), Balsi(Release), Machigi(Ending). At the result, muscle activity of posterior deltoid, trapezius, rhomboid major, latissimus dorsi, biceps brachii, forearm extensor bundle, triceps brachii, levator scapulae significantly increased at event of full draw and release, then significantly decreased again at event of ending, respectively(p<.01, p<.001). The muscle activity of erector spinae(ES) was also significantly increased at event of full draw and release(p<.01, p<.001), while no significant changes in muscles of rectus abdominis, rectus femoris(RF), gluteus maximus. As a result of comparing PSG and OSG, muscle activity of RF in OSG was higher than PSG at event of release(p<.05), it remained until event of ending(p<.05). On the other hand, the higher the tension of the bow, the higher the muscle activity of the draw arm at event of release(p<.05). These results suggest that when Korean traditional archery shooting, both side arm and back muscles are more activated than the abdomen, leg and hip muscles. The parallel stance might suppress the muscle activity of the lower extremities to twist the upper body. And the higher bowstring tension needs to increase of muscle strength in BB of draw arm.

Composition and abundance of microbiota in the pharynx in patients with laryngeal carcinoma and vocal cord polyps

Hongli Gong,Boyan Wang,Yi Shi,Yong Shi,Xiyan Xiao,Pengyu Cao,Lei Tao,Yuezhu Wang,Liang Zhou 한국미생물학회 2017 The journal of microbiology Vol.55 No.8

The pharynx is an important site of microbiota colonization, but the bacterial populations at this site have been relatively unexplored by culture-independent approaches. The aim of this study was to characterize the microbiota structure of the pharynx. Pyrosequencing of 16S rRNA gene libraries was used to characterize the pharyngeal microbiota using swab samples from 68 subjects with laryngeal cancer and 28 subjects with vocal cord polyps. Overall, the major phylum was Firmicutes, with Streptococcus as the predominant genus in the pharyngeal communities. Nine core operational taxonomic units detected from Streptococcus, Fusobacterium, Prevotella, Granulicatella, and Veillonella accounted for 21.3% of the total sequences detected. However, there was no difference in bacterial communities in the pharynx from patients with laryngeal cancer and vocal cord polyps. The relative abundance of Firmicutes was inversely correlated with Fusobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes. The correlation was evident at the genus level, and the relative abundance of Streptococcus was inversely associated with Fusobacterium, Leptotrichia, Neisseria, Actinomyces, and Prevotella. This study presented a profile for the overall structure of the microbiota in pharyngeal swab samples. Inverse correlations were found between Streptococcus and other bacterial communities, suggesting that potential antagonism may exist among pharyngeal microbiota.