Video quality adaptation to limit energy usage in mobile systems

Jeong, Hyunmi,Yang, Jinwoo,Song, Minseok IEEE 2016 IEEE transactions on consumer electronics Vol.62 No.3

<P>In mobile systems, it is essential to limit the amount of energy consumption if the energy budget is low. This paper proposes a new scheme that makes use of quality scalability in scalable video coding (SVC) to limit energy usage by taking quality-of-experience (QoE) factors into account. To address the tradeoff between QoE and energy consumption, a new dynamic voltage and frequency scaling (DVFS) technique is proposed in which the fidelity level of each video segment is dynamically selected. The proposed scheme estimates the amount of energy consumption based on the analysis of the computational requirements to decode previous frames, and chooses the fidelity level to achieve the best video quality metric (VQM) value within a given energy budget. It was implemented on a recent commercial smartphone in which a new interface is provided for users to control the energy usage based on video quality. Real measurements show that it makes effective use of the remaining battery while maximizing QoE(1).</P>

계층적 비디오 코딩의 품질확장성을 활용한 전력 관리 기법

정현미(Hyunmi Jeong),송민석(Minseok Song) 한국정보과학회 2014 정보과학회 컴퓨팅의 실제 논문지 Vol.20 No.11

미디어 플레이어에서의 디코딩 과정은 많은 연산을 필요로 하며, CPU로부터 높은 소비전력을 초래한다. 디코딩 연산을 줄이는 것은 CPU 소비 전력을 감소시킬 수 있지만 사용자로부터 비디오 품질을 저하시키게 된다. 본 논문에서는 H.264의 품질 확장성을 이용하여 새로운 CPU 전력 관리 기법을 제안한다. 첫째, VQM(Video Quality Metric)을 사용하여 계층적 비디오 코딩의 서로 다른 양자화 인자를 고려한 새로운 비디오 품질 모델을 제안한다. 그리고 이전 디코딩 시간과 프레임 크기를 선택적으로 융합한 디코딩 시간 예측기법에 기반한 새로운 동적 전압 기법을 제안한다. 최신 스마트폰에서 구현하였고, 사용자 테스트를 수행하였다. 제안한 기법을 실제 측정에 적용하였을 때 리눅스 동적 전압 및 주파수 조절(DVFS) 거버너에 비해 34%의 에너지 감소를 보였고 사용자 테스트를 통해 실험 영상의 품질 하락을 사용자는 인지하지 못하거나 용인될 수 있음을 확인하였다. Decoding processes in portable media players have a high computational cost, resulting in high power consumption by the CPU. If decoding computations are reduced, the power consumed by the CPU is also be reduced, but such a choice generally results in a degradation of the video quality for the users, so it is essential to address this tradeoff. We proposed a new CPU power management scheme that can make use of the scalability property available in the H.164/SVC standard. We first proposed a new video quality model that makes use of a video quality metric(VQM) in order to efficiently take into account the different quantization factors in the SVC. We then propose a new dynamic voltage scaling(DVS) scheme that can selectively combine the previous decoding times and frame sizes in order to accurately predict the next decoding time. We then implemented a scheme on a commercial smartphone and performed a user test in order to examine how users react to the VQM difference. Real measurements show that the proposed scheme uses up to 34% fewer energy than the Linux DVFS governor, and user tests confirm that the degradation in the quality is quite tolerable.

H.264/SVC의 품질 확장성을 활용한 CPU 전력 관리 기법

정현미(Hyunmi Jeong),송민석(Minseok Song) 한국정보과학회 2014 한국정보과학회 학술발표논문집 Vol.2014 No.6

Graphical and SERS dual-modal identifier for encoding OBOC library

Kang, Homan,Koh, Yul,Jeong, Sinyoung,Jeong, Chulhwan,Cha, Myeong Geun,Oh, Min-Hye,Yang, Jin-Kyoung,Lee, Hyunmi,Jeong, Dae Hong,Jun, Bong-Hyun,Chang, Hyejin,Kim, Yong-Kweon,Lee, Yoon-Sik Elsevier 2020 Sensors and actuators. B, Chemical Vol.303 No.-

<P><B>Abstract</B></P> <P>‘Split-and-mix’ synthetic methods are widely utilized to prepare extensively large numbers of combinatorial libraries. For this, a simple and reliable encoding/decoding method is required to identify a lead compound, especially when it comes to combinatorial peptide/peptoid libraries. Here, we report a simple, efficient, and reliable on-bead peptoid ligand identification method using dual-modal identifiers (DM-IDs), which have a graphical pattern and a Raman signal. The DM-ID was designed to encode the sequence and the type of peptoid side chain by the number of holes and the surface-enhanced Raman scattering (SERS) signals, respectively. Using this dual encoding strategy, 5832 (18<SUP>3</SUP>)-individual peptides/peptoids can be encoded with 3 holes and 18 Raman label compounds. In addition, the method can be easily extended to encode more than one hundred billion ligands by expanding to 9 patterns with 3 holes in binary code. After pentapeptoids were encoded with DM-IDs during solid phase synthesis, the peptoid’s affinity towards streptavidin is successfully evaluated, and the on-bead peptoid sequence is determined by the graphical patterns and the SERS signatures of the DM-IDs. We believe that this encoding method using DM-IDs is a promising tool to construct one-bead-one-compound (OBOC) combinatorial libraries for drug discovery.</P> <P><B>Highlights</B></P> <P> <UL> <LI> On-bead peptoid ligand identification method using dual-modal identifiers (DM-IDs) is demonstrated. </LI> <LI> The DM-ID with graphical (hole structure) and optical (SERS spectrum) codes is successfully fabricated. </LI> <LI> The DM-ID is designed to dictate the sequence of peptoid ligand and the type of side chain. </LI> <LI> More than one hundred billion (18<SUP>9</SUP>)-individual ligands can be encoded with 9-hole patterns and 18 Raman label compounds. </LI> </UL> </P>

A survey investigating the current situation of the international visiting scholar program at the department of surgery in Korea

Seung-Bum Ryoo,Hyunmi Park,Yoon Dae Han,Hyeong-Gon Moon,Hee Jeong Kim,Kyung Chul Yoon,Jaseong Bae,Yang Jin Park,Jai Young Cho,Woon Kyung Jeong,Seung-Yong Jeong 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.99 No.4

Purpose: The number of international visiting scholars has been on the increase in Korea and we aim to investigate the program’s current situation. Methods: This cross-sectional study is based on an online survey questionnaire responded by international visiting scholars in surgical departments of 8 Korean hospitals between 2014 and 2018 about their experiences and satisfaction with the visiting scholar program. Results: A total of 1,496 international scholars from 80 countries visited various surgical departments in 8 Korean hospitals between 2014 and 2018. The numbers have been on the increase over the years. Out of 355 visiting scholars in 2018, 71 replied to the online survey, of whom 52 were male and 19 female, and mostly in their 30s and 40s. Information about the program was accessed mostly through friends or colleagues (42.3%) and international conferences (36.6%). The commonest funding source was private (35.2%) and more than half stayed for less than 3 months. The visiting scholar’s main roles were mostly observation or participation in surgery and clinical research. All but 1 were satisfied with the program (98.6%) and would recommend it to friends and colleagues, although the language barrier was identified as an inconvenience. Those aged 20–39 years with governmental or institutional funding were associated with stays of more than 1 year. Conclusion: The number of international visiting scholars at surgical departments in Korean hospitals has been on the increase with high satisfaction levels. Improvements need to be made on funding sources and lengthening visiting period to maximize the benefits of the program.

Hepatoprotective Effect of a Mixture Including Extract of Houttuynia cordata Thunb. against Alcohol-induced Toxicity in Mice

Hyunmi Lee,Haneul Jo,Yanghee You,Jeongjin Park,Changsik Jeong,Minjae Lee,Woojin Jun 한국식품영양과학회 2016 한국식품영양과학회 학술대회발표집 Vol.2016 No.10

연결재무제표 외부감사 시 타감사인 활용이 연결이익조정에 미치는 영향

지현미(Hyunmi Ji),박홍조(Hongjo Park),정태범(Taebeom Jeong) 한국산업경영학회 2010 한국산업경영학회 발표논문집 Vol.2010 No.2

우리나라는 세계적인 회계기준 단일화 추세에 부응하기 위하여 2007년 3월에 국제회계기준 도입을 위한 로드맵을 발표하고 2011년부터 국제회계기준을 전면 도입하기로 하였다. 한국채택국제회계기준에 따르면, 연결재무제표가 기본 재무제표로 되기 때문에 종전에 비해 연결재무제표의 역할이 한층 강화된다. 하지만 지배회사 외부감사인이 연결재무제표를 감사 할 때 종속회사 재무제표에 대해서는 타감사인의 감사 결과를 활용하는 것이 일반적인데, 만일 이 같은 타감사인의 활용이 연결재무제표의 정보적 신뢰성을 저해하는 요인으로 작용한다면 연결재무제표를 기본 재무제표로 하는 국제회계기준 도입의 취지가 상당부분 훼손될 수 있다. 이에 따라 본 연구에서는 연결재무제표를 감사하는 지배회사의 감사인이 종속회사의 재무제표를 감사한 타감사인의 감사의견을 얼마나 활용하는지 살펴보고, 그 활용정도와 자의적인 연결이익조정간의 관계를 검증해 보았다. 또한 이러한 검증 결과를 토대로 종속회사 재무제표에 대한 타감사인의 감사결과 활용에 대한 적절한 방향을 제시하고자 하였다. 연결재무제표에 대한 외부감사 시 지배회사 외부감사인의 타감사인 활용정도는 연결감사 보고서에 공시되는 자료를 이용하여, 연결감사보고서에 기재된 자산기준 타감사인 활용비율로 측정하였다. 연결이익조정의 측정치는 Kothari et al.(2005)의 모형을 기초로 연도별-산업별 횡단면 분석모형을 통해 추정한 재량적 발생액을 사용하였다. 또한 본 연구의 표본은 유가증권시장에 상장되어 있으면서 연결재무제표를 작성.공시하는 지배회사 중 금융업에 속하지 않는 2001년부터 2006년 사이의 12월 결산법인 860개 기업-년으로 구성되었다. 실증분석 결과, 연결재무제표에서 지배회사 감사인의 타감사인 활용정도가 높을수록 연결재무제표의 재량적 발생액이 증가하는 것으로 나타났다. 이러한 결과는 지배회사의 외부감사인이 연결재무제표를 감사하는 과정에서 그 종속회사의 재무제표에 대한 타감사인 활용정도가 클수록 연결이익조정도 함께 더 커지므로, 타감사인의 활용이 연결재무제표의 신뢰성을 저해하는 요인으로 작용한다고 해석할 수 있다. 본 연구의 공헌점은 국제회계기준 도입에 따라 연결재무제표가 기본 재무제표로 되는 상황에서 연결실체 내에서 타감사인 활용정도가 높을수록 연결이익조정이 더 많아진다는 것을 실증적으로 검증하였다는 점이다. 따라서 연결실체 내의 지배회사와 종속회사가 동일한 감사인을 선임하도록 하는 규정을 제도화해야 하는지에 대한 정책적 시사점을 제공할 수 있으리라 기대된다. As adoption K-IFRS, consolidated financial statements will be main financial reporting tools and the importance of these statements will be enhanced dramatically. Principal auditors of consolidated financial statements generally use the work of another auditor for subsidiaries. However this audit procedure for practical convenience can impair transparency and reliability of consolidated financial statements. It is because the difference of external auditors between parents and subsidiaries would be chance of discretional earnings management. We examine empirically the effect of using the work of another auditor on earnings management of consolidated financial statements. Therefore, we hypothesize that the more principal auditors of parents companies rely on the work of another auditor, the more will the firm manage their reported income of consolidated financial statements. We have performed empirical tests using 860 firm-year sample firms with consolidated financial statements from year 2001 to 2006. Our results show that parents firms using more the work of another auditor made more upward reported income managements. The results of our study imply that excessive reliance on the work of another auditor can impair the transparency and reliability of consolidated financial reporting. Therefore, regular authority should consider making subsidiaries assign same external auditors with parents companies. This study contributes to earnings management researches in that it provides empirical evidence that using the work of another auditor can be chance for upward reported earnings management in consolidated financial statements.

LSTM 모형을 이용한 수소 버스의 에너지 소비율 예측 모델 연구

이현미(Hyunmi Lee),장정아(Jeong-Ah Jang),김시우(Si Woo Kim),류도정(Dojeung Ryu) 한국가스학회 2022 한국가스학회 학술대회논문집 Vol.2022 No.5

산 염기 중화반응에 따른 부피 증가의 원인 탐구

박현미 ( Hyunmi Park ),서정쌍 ( Jung Sang Suh ),정대홍 ( Dae Hong Jeong ) 한국현장과학교육학회 2007 현장과학교육 Vol.1 No.1

본 연구에서는 고등학교 과학 교과서에 제시된 중화반응 실험에서 반응이 일어날 때 부피가 증가하는 현상에 대한 학생들의 인식을 조사하고 이에 관한 실험을 수행하여 그 원인을 분석하였다. 서울 소재 대학교 화학전공 2학년 학생들을 대상으로 이 현상의 원인에 대한 인식을 조사하였다. 조사결과 학생들의 대답은 단순히 물의 생성에 의한 부피 증가, 중화열에 의한 부피 팽창, 분자의 배열 변화 등의 의견을 가지고 있었다. 온도를 통제한 실험을 설계하여 염산과 수산화나트륨의 중화반응을 수행하였을 때 온도의 영향은 측정 오차범위 안으로 들어갈 만큼 적게 나타났다. H+와 OH- 이온으로 존재할 때와 물로 존재할 때의 부피 차이로 물의 생성에 의한 부피 증가의 영향은 이온과 물 분자의 크기를 비교했을 때 그 영향이 크지 않은 것으로 추정되었다. 이온에 의한 물 속 분자들의 배열 변화의 영향은 관찰된 중화반응에 부피 증가량과 비슷한 값을 주어 이 영향이 실질적 원인으로 분석되었다. 즉, H+와 OH- 이온의 주변으로 물 분자가 방향을 가지고 모이면서 물 분자 사이의 배열이 달라지고 전체적으로 물의 부피가 축소되어 있던 것이 중화반응이 일어나면서 H+와 OH- 이온의 수가 급격하게 줄어들면서 부피가 증가한 것으로 해석되었다. In this study, we analyzed the factors causing a volume increase in neutralization reaction experiment presented in high school science textbook. Second graders majoring in chemistry at a university in Seoul were investigated on their conceptions of the experimental result. Students showed such opinions that the volume increased just as much as the amount of water produced, the volume expanded due to the heat of neutralization, molecular rearrangement caused volume change, and so on. Experiments were performed to decide factors that have dominant effects. In an experiment controlling temperature factor, volume change was observed to be within measurement error range. The effect of volume increase by the amount of water produced was also estimated to be negligible. The volume change due to molecular rearrangement by ion in the water was estimated to be similar to the amount of the observed volume in neutralization reaction. Concludingly, it was understood that the volume of water being reduced by H+ and OH- ions, resumed back with a drastic decrease of H+ and OH- ions when the neutralization reaction occurred.

Unfavorable outcome of a paranasal cosmetic prosthesis caused by dental implants: a case report

Jo Hyunmi,Oh Yeonjin,Jeong Bong-Jin,Jung Junho,Ohe Joo-Young 대한치과이식(임프란트)학회 2020 The Korean Academy of Implant Dentistry Vol.39 No.3

This article presents an unfavorable outcome of a paranasal cosmetic prosthesis, Medpor, which is affected by dental implants. The paper provides treatment insight for oral and maxillofacial specialists. The patients had undergone mandibular set-back surgery combined with both paranasal augmentations using Medpor. In due course, dental implants were placed on the anterior maxilla a few years later. The patient suffered from persistent pain and purulent discharge, but no significant correlation was observed on the panorama and CBCT. Dental implants were inserted near the Medpor for a paranasal augmentation, affecting each other, resulting in clinical symptoms. Medpor, as a radiolucent material, was not visible on dental radiography. Its characteristics of a bony-like texture and color could mislead dentists to misjudge a bony structure clinically. Therefore, the dental implant fixtures were inserted near the Medpor. The Medpors on the affected area were infected, requiring it to be surgically removed. This suggests that both dental implants and Medpors failed. A comprehensive evaluation of patient history and strategic presurgical planning should be obtained to avoid an inappropriate consequence of grafting.