Atomic layer deposited HfO[sub 2]/HfSi[sub x]O[sub y]N[sub z] stacked gate dielectrics for metal-oxide-semiconductor structures

Kim, Seokhoon,Woo, Sanghyun,Kim, Hyungchul,Jeong, Wooho,Park, Taeyong,Kim, Honggyu,Kim, Sung Bae,Jeon, Hyeongtag American Vacuum Society 2007 JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B - Vol.25 No.6

Atomic Layer Deposition of HfO2 Thin Films on Ultrathin SiO2 Formed by Remote Plasma Oxidation

Seokhoon Kim,전형탁,Hyungchul Kim,Inhoe Kim,Keunwoo Lee,Sanghyun Woo,Taeyong Park,Wooho Jeong 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4

An ultrathin SiO₂ layer was grown on a H-terminated Si substrate by using remote plasma oxidation. The subsequent HfO₂ deposition on the ultrathin SiO₂ was achieved by a remote plasma atomic layer deposition (RPALD). During the HfO₂ film deposition and rapid thermal annealing (RTA), the ultrathin SiO₂ buffer layer effectively suppressed the formation of Hf silicate layers in the interfacial region. The Hf silicate layer in the interfacial region grew with increasing RTA temperature. The positive fixed oxide charges in the HfO₂ film were reduced with increasing RTA temperature. The thickness of the HfO₂ films with an ultrathin SiO₂ buffer layer showed a lower effective fixed oxide charge density (Qf,eff) due to the shift of the flat band voltage (VFB) toward the positive direction, compared to those with H-terminated Si. The thin interfacial layer of the HfO₂ films with a thin SiO₂ buffer layer resulted in a low equivalent oxide thickness (EOT) value. The leakage current densities of the HfO₂ films increased because of the crystallization of the HfO₂ film after RTA. An ultrathin SiO₂ layer was grown on a H-terminated Si substrate by using remote plasma oxidation. The subsequent HfO₂ deposition on the ultrathin SiO₂ was achieved by a remote plasma atomic layer deposition (RPALD). During the HfO₂ film deposition and rapid thermal annealing (RTA), the ultrathin SiO₂ buffer layer effectively suppressed the formation of Hf silicate layers in the interfacial region. The Hf silicate layer in the interfacial region grew with increasing RTA temperature. The positive fixed oxide charges in the HfO₂ film were reduced with increasing RTA temperature. The thickness of the HfO₂ films with an ultrathin SiO₂ buffer layer showed a lower effective fixed oxide charge density (Qf,eff) due to the shift of the flat band voltage (VFB) toward the positive direction, compared to those with H-terminated Si. The thin interfacial layer of the HfO₂ films with a thin SiO₂ buffer layer resulted in a low equivalent oxide thickness (EOT) value. The leakage current densities of the HfO₂ films increased because of the crystallization of the HfO₂ film after RTA.

Communicating Healthy Food Choice

Sang-Yeon Kim,Jennifer Morey Hawkins,Hayeon Song,Tae-Seop Lim,Emily McCarthy. Cramer,Seokhoon Ahn,Jihyun Kim,Hyun-Joo Kim,Junghyun Kim,Hiroshi Ota 한국언론학회 2016 Asian Communication Research Vol.13 No.1

This research examines cultural influence on the preference of promotive (i.e., trying to eat more healthy foods) and preventive (i.e., trying to avoid unhealthy foods) dietary practices. Survey data were collected from students and older adults in Korea (N = 287) and the U.S. (N = 245). Only students participated in the survey in Japan (N = 145). Consistent with the prediction, Study 1 shows Korean mature adults are more willing to adopt preventive dietary practices, while American counterparts favor promotive eating habits. The pattern of the data was inconsistent with the prediction among student participants across the three nations. Individual-level data from Study 2 (N = 284) confirm that independent self-construal affects promotive dietary practice via increasing promotive regulatory self-focus. The indirect impact of interdependent self-construal on preventive dietary practice was less apparent. Practical implications for doctor-patient communication are discussed.

Toward High-Performance Hematite Nanotube Photoanodes: Charge-Transfer Engineering at Heterointerfaces

Kim, Do Hong,Andoshe, Dinsefa M.,Shim, Young-Seok,Moon, Cheon-Woo,Sohn, Woonbae,Choi, Seokhoon,Kim, Taemin Ludvic,Lee, Migyoung,Park, Hoonkee,Hong, Kootak,Kwon, Ki Chang,Suh, Jun Min,Kim, Jin-Sang,Lee American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.36

<P>Vertically ordered hematite nanotubes are considered to be promising photoactive materials for high-performance water-splitting photoanodes. However, the synthesis of hematite nanotubes directly on conducting substrates such as fluorine-doped tin oxide (FTO)/glass is difficult to be achieved because of the poor adhesion between hematite nanotubes and FTO/glass. Here, we report the synthesis of hematite nanotubes directly on FTO/glass substrate and high-performance photoelectrochemical properties of the nanotubes with NiFe cocatalysts. The hematite nanotubes are synthesized by a simple electrochemical anodization method. The adhesion of the hematite nanotubes to the FTO/glass substrate is drastically improved by dipping them in nonpolar cyclohexane prior to postannealing. Bare hematite nanotubes show a photocurrent density of 1.3 mA/cm(2) at 1.23 V vs a reversible hydrogen electrode, while hematite nanotubes with electrodeposited NiFe cocatalysts exhibit 2.1 mA/cm(2) at 1.23 V which is the highest photocurrent density reported for hematite nanotubes-based photoanodes for solar water splitting. Our work provides an efficient platform to obtain high-performance water-splitting photoanodes utilizing earth-abundant hematite and noble-metal-free cocatalysts.</P>

Indoor Location Determination Technology for Disaster States

Seokhoon Kim,JaiPyo Sung 중소기업융합학회 2015 중소기업융합학회 국제학술대회논문집 Vol.2 No.1

According to the expanding modern people's life time in the indoor, the importance of indoor LBS have been continuously gotten higher attention. This phenomenon is one of the inevitable IT trends which caused by the evolved computing paradigm, mobile and wireless communication technologies and Internet of Things. Although there are still several problems which are related to the accuracy and precision, it can be certainly overcome in the near future. However, the practical uses of indoor LBS are applied in some limited fields such as marketing, finance, and so on. So, we propose the improved indoor location determination technology, which is very suitable for disaster states, due to the fact that indoor LBS is more helpful technology when such emergency occurs, if the service, which has more applicable algorithms, can be used in the circumstances. The proposed technology will be a priming and trigger to save our life.

Traffic management in the mobile edge cloud to improve the quality of experience of mobile video

Kim, Seokhoon,Kim, Dae-Young,Park, Jong Hyuk Elsevier 2018 Journal of Computer Communications Vol.118 No.-

<P><B>Abstract</B></P> <P>The use of mobile network traffic is increasing due to the development of communication devices such as smart phones. Data traffic accounts for more than voice traffic. Video traffic accounts for the largest proportion of mobile data traffic and this proportion is increasing. However, various mobile environments affect the status of the mobile network and limit the provision of video services using the Internet. Therefore, a method for improving the quality of experience (QoE) of a video service in mobile environments is required. This paper presents a traffic management method using the mobile edge cloud. The mobile edge cloud is placed in the mobile edge network and monitors the status of mobile terminals. Through the mobile edge cloud, it becomes possible to effectively manage the traffic of mobile terminals by the network. The proposed method manages video traffic from the content server on the Internet according to the edge network status and mobility of a mobile terminal, and provides video traffic to mobile terminals. This method, using the mobile edge cloud, leads to improvement of the QoE for mobile video users. The superiority of this method compared to currently available systems was validated by computer simulation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper provides a traffic management method using the mobile edge cloud. The mobile edge cloud is placed in the mobile edge network and monitors the status of mobile terminals. Through the mobile edge cloud, it becomes possible to manage the traffic of mobile terminals effectively by the network. </LI> <LI> The proposed method manages video traffic from the content server in the Internet according to the edge network status and mobility of a mobile terminal and provides the video traffic to the mobile terminals. </LI> <LI> The proposed method using the mobile edge cloud leads to improvement of the QoE of mobile video users. </LI> <LI> By computer simulation, the superiority is validated. </LI> </UL> </P>

Packet Forwarding Scheme Based on Interworking Architecture for Future Internet

KIM, Seokhoon,RYOO, Intae The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.3

<P>This paper introduces a packet forwarding scheme based on interworking architecture that can provide quite a good QoS by minimizing processing delay which is the major part of the timeliness factor in New Generation IP-based networks. Based on path and resource reservation mechanism, the POSIA makes routers on the packet forwarding path synchronize with each other and then forward packets. We have shown that the POSIA outperforms the existing packet forwarding schemes like IntServ, DiffServ and MPLS through computer simulations using OPNET.</P>

Adaptive data rate control in low power wide area networks for long range IoT services

Kim, Dae-Young,Kim, Seokhoon,Hassan, Houcine,Park, Jong Hyuk Elsevier 2017 Journal of computational science Vol.22 No.-

<P><B>Abstract</B></P> <P>Internet of Things (IoT) technologies can provide various intelligent services by collecting information from objects. To collect information, Wireless Sensor Networks (WSNs) are exploited. The Low Power Wide Area Network (LPWAN), one type of WSN, has been designed for long-range IoT services. It consumes low power and uses a low data rate for data transmission. The LPWAN includes several communication standards, and Long Range Wide Area Network (LoRaWAN) is the representative standard of the LPWAN. LoRaWAN provides several data rates for transmission and enables adaptive data rate control in order to maintain network connectivity. In the LoRaWAN, the wireless condition is considered by the reception status of the acknowledgement (ACK) message, and adaptive data rate control is performed according to the wireless condition. Because the judgment of the wireless condition by the reception status of ACK messages does not reflect congestion, adaptive data rate control can lead to inefficiency in data transmission. For efficient data transmission in long-range IoT services, this paper proposes a congestion classifier using logistic regression and modified adaptive data rate control. The proposed scheme controls the data rate according to the congestion estimation. Through extensive analysis, we show the proposed scheme’s efficiency in data transmission.</P> <P><B>Highlights</B></P> <P> <UL> <LI> In this paper, the necessity of congestion estimation in long range IoT applications is described. Congestion Classifier using Logistic Regression and the modified adaptive data rate control scheme is designed. </LI> <LI> For the validation of the efficiency of the data transmission, analysis on the transmission delay is carried out. Results show that the proposed method outperforms state of the art methods. </LI> <LI> In this way, the proposal improves transmission efficiency in aspect of the transmission delay in wireless environment where congestion occurs. </LI> <LI> Our proposed method predicts congestion status by learning and determines whether a node drops data rate or not. Thus, it leads to avoiding unnecessary change of data rate. </LI> <LI> Through analysis on transmission delay, the proposed scheme has shown that it is the proper data rate control method for IoT networking in congestion environment. </LI> </UL> </P>

Taxonomic notes of Spilonota Stephens (Lepidoptera: Tortricidae: Olethreutinae) in Korea

Seokhoon Choi,Jeong-Nam Kim,Hanul Kim,Chang-Moon Jang,Tak-Gi Lee,Ulziijargal Bayarsaikhan,Yang-Seop Bae 한국응용곤충학회 2023 한국응용곤충학회 학술대회논문집 Vol.2023 No.04

Taxonomic notes of Spilonota Stephens and Lepteucosma Diakonoff (Lepidoptera: Tortricidae: Olethreutinae) in Korea

Seokhoon Choi,Jeong-Nam Kim,Hanul Kim,Ulziijargal Bayarsaikhan,Yang-Seop Bae 한국응용곤충학회 2023 한국응용곤충학회 학술대회논문집 Vol.2023 No.10

The genera Spilonota Stephens, 1834 and Lepteucosma Diakonoff, 1971 are belonging to the tribe Eucosmini, subfamily Olethreutinae. In Korea, there are five species of Spilonota recorded: S. albicana (Motschulsky, 1866), S. eremitana Moriuti, 1972, S. lechriaspis Meyrick, 1932, S. ocellana ([Denis & Schifferm?ller], 1775), and S. semirufana (Christoph, 1882). Only one species of Lepteucosma is recorded: L. huebneriana (Kocak, 1980). Both genera are agricultural pests that infest host plants belonging to the family Rosaceae, specifically causing damage to genus Malus (apple trees) and genus Rubus (blackberry plants), respectively. In this study, we provide a checklist of Korean Spilonota and Lepteucosma, with information of host plants and distribution for each examined species.