http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Idiosyncratic risk and foreign investors : Empirical evidence from the Korean stock market
Junho Hwang 한국재무학회 2019 한국재무학회 학술대회 Vol.2019 No.11
This paper examines the effect of foreign ownership on idiosyncratic risk of individual stock in Korean stock market. We find that foreign ownership is negatively related to idiosyncratic risk. This result is robust to multiple idiosyncratic risk measures and regression methods. We find two underlying channels through which foreign ownership reduces the idiosyncratic risk: through influencing price informativeness and enhancing monitoring effect. Our results support that foreign investors reduce the idiosyncratic risk by enhancing monitoring, while the informativeness channel has weaker explanatory power.
황준호(JunHo Hwang) 대한용접·접합학회 2017 대한용접·접합학회지 Vol.35 No.4
Titanium, which is called ‘wonder metal’ has a variety of structural functions. Because of this, Titanium usage is increasing in higher value-added industries. Application technologies related to Titanium are also rapidly developing. Titanium has excellent specific strength and corrosion resistance. It also has a characteristic of low thermal strain and human-friendly. Due to these characteristics, the Titanium powder is being spotlighted as 3D printing material. Representative methods for producing titanium powders are roughly divided into three processes: gas atomization, hydrogenation-dehydrogenation(HDH), and plasma rotating electrode process(PREP). In particular, the water atomizing, which is a typical method for producing metal powder at low cost in general, is not suitable for producing titanium powder for 3D printing. This paper introduces the manufacturing process and market trends of titanium powder for 3D printing.
가시광 무선 랜 시스템에서 통신지연 감소를 위한 FDD 기반의 개선된 MAC 프로토콜
황준호(Junho Hwang),유명식(Myungsik Yoo) 대한전자공학회 2012 전자공학회논문지 Vol.49 No.10
가시광 무선 통신 기술은 LED와 PD를 이용한 차세대 무선 통신 기술로서 다양한 실내 응용 서비스 제공이 가능하다. 특히 가시광 무선 랜 서비스는 효율적인 조명 기능 이외에 고속의 데이터 전송이 가능하다는 점과 기존 ISM 대역 기반의 WPAN 통신 기술과의 간섭 회피가 가능하다는 점에서 새로운 WLAN 기술로 많은 관심을 받고 있다. 하지만 기존에 연구된 MAC 프로토콜은 상향 링크 접속 시 충돌이 발생하는 경우 충돌 인식 및 백오프 시간 등으로 인해 통신 지연이 발생한다. 이에 본 논문에서는 FDD 기반의 VLAN 시스템에서 상향 링크 프레임과 하향 링크의 프레임의 전송 시간차 이용하여 통신 지연을 최소화시킬 수 있는 MAC 프로토콜을 제안한다. 이와 더불어 모의실험을 토대로 제안하는 MAC 프로토콜의 통신 지연 감소를 확인할 수 있었다. The visible light communication takes advantages of LED and PD for communication and is considered as a next generation wireless communication technology. It can support variety indoor applications. Especially, Visible LAN service has drawn much attention due to high data rate and no interference with existing WPAN system as well as high efficiency in illumination . However, existing MAC protocol occurs a high communication delay due to uplink collision and backoff time. In this paper, to reduce packet delay, we propose an enhanced MAC protocol based on FDD where the time difference between uplink frame and downlink frame transmission is utilized. Through computer simulations, we verified that the proposed MAC protocol outperforms the existing MAC protocol in terms of average packet delay.