Ankle Joint Cooling did not but Knee Joint Cooling altered the Quadriceps and Gastrocnemius Neuromuscular Activation During a Single-leg Drop Jump

( Jihong Park ),( Kyeongtak Song ),( Sae Yong Lee ),( Hohyung Ryu ) 한국운동생리학회(구 한국운동과학회) 2020 운동과학 Vol.29 No.3

PURPOSE: We examined the immediate effect on ankle or knee joint cooling on the lower-extremity activation during a single-leg drop jump. METHODS: Twenty healthy adults randomly completed three data collection sessions (a 20-minute ankle or knee joint cooling, or control). Two wireless surface electromyography (EMG, 2,000 Hz) electrodes were attached over the vastus medialis (VM) and the medial gastrocnemius (MG) on their right limb. Subjects were asked to drop down from a wooden box (a 30-cm height) on their right foot onto the force platform (2,000 Hz) and then performed an immediate jump as high as they could. Whole EMG signals (normalised by the mean EMG value recorded during a reference position) within the preactivation (100-ms prior to contact) and the ground contact (on the force platform) during the drop jump task were analysed using functional linear models (p=.05, Cohen’s d effect size: ES). RESULTS: After knee joint cooling, (1) the VM activation was decreased during the ground contact (6 to 14%, 30 to 45%, 60 to 90% for ES of 0.50, 0.47, and 0.61, respectively) and (2) the MG activation was increased during the preactivation (84- to 29-ms prior to initial contact, ES=1.30) and the ground contact (59 to 100%, ES=1.40). No changes were observed under the condition of ankle joint cooling or control. CONCLUSIONS: A 20-minute unilateral knee joint cooling may result in an ipsilateral quadriceps inhibition during a drop jump task. The gastrocnemius appears to increase activation as a compensatory strategy responding to the quadriceps inhibition. The altered neuromuscular activations do not seem to put an individual at risk of injury, resulting from compressive forces in the sagittal plane.

Knee Joint Cooling Inhibits Quadriceps but Facilitates Gastrocnemius Activation During A Single-leg Drop Jump Do We Need to Screen Before Starting Prevention Intervention?

( Jihong Park ),( Kyeongtak Song ),( Sae Yong Lee ),( Hohyung Ryu ) 대한운동사협회 2019 대한운동사협회 운동사대회자료집 Vol.2019 No.-

MERS 사태에 대한 대응 네트워크 분석

김지홍(Jihong Kim),송준호(Junho Song),김유심(Yushim Kim),구민영(Minyoung Ku),오성수(Seong Soo Oh),박희진(Heejin Park),차재혁(Jaehyuk Cha),김상욱(Sang-wook Kim) 한국정보과학회 2018 한국정보과학회 학술발표논문집 Vol.2018 No.12

지식자본과 기업 생산성: 특허 자료를 중심으로(1)

이지홍(Jihong Lee),김상동(Sangdong Kim),송근상(Keunsang Song) 서울대학교 경제연구소 2019 經濟論集 Vol.58 No.2

본 연구는 2003~2013년 기간 동안 한국 또는 미국 특허청에 특허활동 이력이 있는 504개의 국내 상장기업을 대상으로 지식자본과 기업 생산성의 상관관계를 분석한다. 단순 특허등록 수 외에 피인용 횟수를 기반으로 특허의 질을 반영한 특허스톡을 고려한 결과, 특허변수가 기업의 유형자산 및 노동투입 규모에 의해 설명되지 않는 실질매출 중 일부를 통계적으로 유의하게 설명할 수 있음을 확인하였다. 이러한 결과는 특허정보가 기업의 지식자본을 측정하는 대리변수로 활용될 수 있음을 시사한다. This paper analyzes the relationship between knowledge capital and firm productivity for 504 Korean listed firms that have registered patents in Korea or US during the period 2003-2013. We find various measures of patent stock that can explain firm revenue with statistical significance in addition to tangible capital and labor inputs. This result suggests that patent stock can be utilized as a proxy for measuring corporate knowledge capital.

A Study on Word Sense Disambiguation Using Bidirectional Recurrent Neural Network for Korean Language

Min, Jihong,Jeon, Joon-Woo,Song, Kwang-Ho,Kim, Yoo-Sung 한국컴퓨터정보학회 2017 韓國컴퓨터情報學會論文誌 Vol.22 No.4

Word sense disambiguation(WSD) that determines the exact meaning of homonym which can be used in different meanings even in one form is very important to understand the semantical meaning of text document. Many recent researches on WSD have widely used NNLM(Neural Network Language Model) in which neural network is used to represent a document into vectors and to analyze its semantics. Among the previous WSD researches using NNLM, RNN(Recurrent Neural Network) model has better performance than other models because RNN model can reflect the occurrence order of words in addition to the word appearance information in a document. However, since RNN model uses only the forward order of word occurrences in a document, it is not able to reflect natural language's characteristics that later words can affect the meanings of the preceding words. In this paper, we propose a WSD scheme using Bidirectional RNN that can reflect not only the forward order but also the backward order of word occurrences in a document. From the experiments, the accuracy of the proposed model is higher than that of previous method using RNN. Hence, it is confirmed that bidirectional order information of word occurrences is useful for WSD in Korean language.

User-Centric Thermal Management for Smartphones

Wook Song,Jihong Kim 한국정보과학회 2018 Journal of Computing Science and Engineering Vol.12 No.4

For high-performance smartphones, keeping the on-chip temperature under a given critical temperature is a major concern. In order to prevent the temperature from rising above the critical point, modern smartphones widely adopt the dynamic thermal management (DTM) scheme, which limits the maximum CPU frequency when the CPU reaches high temperatures (thus making the CPU temperature drop). In this paper, we propose a novel DTM scheme based on userperceived response time analysis called SmartDTM. Unlike existing DTM schemes that can significantly degrade the quality of user experience, SmartDTM explicitly accounts for the quality of the user experience in making DTM decisions. We divide an execution of a given user-interactive session into two intervals, one where the system response time directly affects the user experience and the other where the system response time does not affect the user experience. In the user-perceived response time interval, our proposed scheme conservatively makes DTM decisions so that the quality of the user experience is not affected by the reduced maximum CPU frequency. On the other hand, in the user-oblivious response time interval, SmartDTM aggressively lowers the CPU frequency so that the CPU temperature can be quickly decreased to a safe level without negatively affecting user experience. Our experimental results on an ODROID-XU+E board show that SmartDTM can improve the performances of user-perceived intervals by 12.2% and 21.4% over the Android’s default DTM policy when the initial temperature was set to 65°C and 70°C, respectively, under the critical temperature of 85°C.

한국어를 위한 Recurrent Neural Network 기반 동형이의어 중의성 해소 연구

민지홍 ( Jihong Min ),전준우 ( Joon-woo Jeon ),송광호 ( Kwang-ho Song ),김유성 ( Yoo-sung Kim ) 한국컴퓨터교육학회 2017 한국컴퓨터교육학회 학술발표대회논문집 Vol.21 No.1

영어에 대한 동형이의어의 중의성 해소를 위해 NNLM(Neural Network Language Model)을 사용하는 연구가 이루어지고 있으며, 최근에는 순서정보를 반영하는 신경망 모델인 RNN(Recuurent Neural Network)을 사용한 연구가 진행되고 있다. 본 연구에서는 신경망에 대한 한국어의 특성을 반영해 RNN을 한국어에 대한 동형이의어의 중의성 해소에 적용할 것을 제안하였으며, 실험을 통해 한국어에서도 순서 정보를 반영하는 RNN 기반 동형이의어 중의성 해소 모델이 유효함을 확인하였다.

Inhibition of MicroRNA-92a Improved Erectile Dysfunction in Streptozotocin-Induced Diabetic Rats via Suppressing Oxidative Stress and Endothelial Dysfunction

Tang Zhe,Song Jingyu,Yu Zhe,Cui Kai,Ruan Yajun,Liu Yang,Wang Tao,Wang Shaogang,Liu Jihong,Yang Jun 대한남성과학회 2023 The World Journal of Men's Health Vol.41 No.1

Purpose: To determine whether microRNA could be a therapy target of erectile dysfunction (ED) and the underlying mecha-nisms. Materials and Methods: Eight-week-old fasting male SD rats were intraperitoneally injected with streptozotocin to construct diabetic rat models. Diabetic ED rats were treated with miRNA-92a inhibitor. The cavernous nerves were electrically stimu-lated to measure the intracavernous pressure and mean arterial pressure of rats in each group. After the detection, the penile cavernous tissues are properly stored for subsequent experiments. Rat aortic endothelial cells were used in in vitro studies. Results: The expression of miR-92a was significantly increased in the corpus cavernosum of Streptozocin (STZ)-induced di- abetic rats and injection of miR-92a antagomir into the corpus cavernosum of diabetic rats significantly increased eNOS/NO/ cGMP signaling pathway activities, cavernous endothelial cell proliferation, endothelial cell-cell junction protein expression and decreased the levels of oxidative stress. These changes restored erectile function in STZ-induced diabetic rats. Moreover, in vitro study demonstrated that the miR-92a expression increased significantly in endothelial cells treated with high glucose, inhibiting AMPK/eNOS and AMPK/Nrf2/HO-1 signaling pathways in rat aortic endothelial cells via targeting Prkaa2, causing endothelial dysfunction and overactive oxidative stress, miR-92a inhibitor can improve the above parameters. Conclusions: miRNA-92a inhibitor could exert an inhibition role on oxidative stress and endothelial dysfunction to improve diabetic ED effectively.

한국 특허 패밀리 ― 데이터 구축과 분석

이지홍 ( Lee Jihong ),김상동 ( Kim Sangdong ),송근상 ( Song Keunsang ),김장원 ( Kim Jangwon ) 한국지식재산연구원 2020 지식재산연구 Vol.15 No.4

본 연구는 한국의 특허 패밀리 데이터를 구축하고 분석한다. 이지홍 외 4인(2020)에서 구축한 KoPDP 데이터베이스에 2017년까지의 PCT 국제출원정보를 추가하였다. 구축한 데이터에 의하면 1984년부터 2017년까지 한국에서 578,694건의 PCT특허가 출원되었으며, 이 중 310,508건이 최종 등록되었다. PCT출원 및 전통적인 파리출원을 통해 1990년대 중반부터 한국의 국제 특허 활동이 급증한 것으로 나타난다. 한국에서 출원된 국제 특허의 동등패밀리 데이터는 유럽특허청의 DOCDB를 통하여 구축하였다. 분석 결과, 한국 기업의 패밀리 사이즈는 꾸준히 증가했으며, 이러한 추세는 총자산, 매출, 또는 고용 규모가 큰 기업, 그리고 의약과 정보통신 산업에서 두드러진다. 또한 국제출원된 특허들 중 대다수가 미국특허청에 출원되고 있다. 본 연구는 삼성전자의 국제출원 동향에 대해서도 추가적으로 기술한다. This paper constructs and analyzes Korean patent family data. We expand the KoPDP database of Lee et al.(2020) by collecting information on all PCT applications up to 2017. Between 1984 and 2017, there were 578,694 PCT applications in Korea, 310,508 of which were eventually granted. Korean international patenting accelerated since the mid-1990s, via both PCT and traditional Paris routes. We use EPO’s DOCDB to define equivalent families of all international patent applications made in Korea. Our analysis reveals that patent family size of Korean firms steadily increased, especially for firms associated with high asset value, revenue, or employment, and with drugs & medical and IT & communication sectors. Most of Korean international patent applications involve USPTO. We also document international patenting trends of Samsung Electronics.

고전압 무효전력 보상기를 사용한 대규모 풍력발전 설비의 전력 품질 보상

김지홍(Kim, Jihong),송승호(Song, Seungho),정승기(Jeong, Seunggi) 한국신재생에너지학회 2012 신재생에너지 Vol.8 No.4

This paper describes a transformerless static synchronous campensator (STATCOM) system based on cascade H-bridge multilevel inverter with star configuration. It is designed not only for the dynamic and continuous compensation of the reactive power but also for the improvement of power quality of existing wind power plant. Especially, when the induction generator of wind turbine is directly connected to the grid, reactive power are occurred by exiting current. so a reactive power compensation system based on the cascade H-bridge multilevel STATCOM is proposed because the output power quality and controllability of reactive power are required by grid code in many different countries. Using various The proposed reactive power control strategy using a STATCOM is compared with the conventional scheme using fixed-size of capacitor bank through various simulation results.