A Backoff Algorithm Based on Residual Energy for Medium Access Control in Wireless Sensor Networks

Chiwoo Cho,Jinnyun Kim,Icksoo Lee,Seokyeol Heo,Kijun Han 대한전자공학회 2006 ICEIC:International Conference on Electronics, Inf Vol.2006 No.6

Growth hormone treatment for children with mucopolysaccharidosis I or II

Minji Im,Chiwoo Kim,Juyoung Sung,Insung Kim,Ji-Hoon Hwang,Min-Sun Kim,Sung Yoon Cho 대한의학유전학회 2023 대한의학유전학회지 Vol.20 No.2

Purpose: Despite enzyme replacement therapy (ERT) and/or allogeneic hematopoietic stem cell transplantation, individuals with mucopolysaccharidosis (MPS) I or II often experience significant growth deficiencies. This study aimed to assess the safety and efficacy of recombinant human growth hormone (hGH) treatment in children diagnosed with MPS I or II. Materials and Methods: A total of nine pediatric patients—four with MPS I and five with MPS II—underwent treatment with ERT and hGH at Samsung Medical Center. Results: The mean hGH dose administered was 0.26±0.03 mg/kg/week. In the MPS I group, three patients showed an increase in height Z-score from -4.09±0.83 to -3.68±0.43 after 1 year of hGH treatment, and to -3.10±0.72 by the end of the hGH regimen. In the MPS II group, while the height Z-score of four patients decreased according to standard growth charts, it improved from 1.61±1.79 to 2.71±1.68 based on the disease-specific growth chart through hGH treatment. Two patients discontinued hGH treatment due to lack of efficacy after 22 and 6 months each of treatment, respectively. No new-onset neurological symptoms or necessity for prosthetic or orthopedic surgery were reported during hGH treatment. Conclusion: This study provides insights into the impact of hGH on MPS patients, demonstrating its potential to reverse growth deceleration in some cases. Further research is needed to explore the long-term effects of hGH on changes in body composition, muscle strength, and bone health in this population.

모바일 디바이스 배터리 소모 분석 기법

송지영(Jiyoung Song),조치우(Chiwoo Cho),정유림(Youlim Jung),지은경(Eunkyoung Jee),배두환(Doo-Hwan Bae) 한국정보과학회 소프트웨어공학 소사이어티 2018 소프트웨어공학회지 Vol.27 No.1

제한된 자원인 모바일 디바이스 배터리의 소모는 회로 설계자들이 회로를 분석 및 평가할 때 중요한 척도가 된다. 기존의 모바일 디바이스 배터리 소모 분석을 위해 여러 배터리 소모 모델 생성 연구가 수행되었으며, 배터리 소모 모델 생성 기법은 센서의 사용 유무, 런타임 모델 생성 여부, 검증 및 테스팅 목적으로의 모델 이용 여부 등에 따라 서로 다른 특징을 가진다. 본 연구에서는 모바일 디바이스회로 설계자들이 회로를 분석하는데 도움을 주기 위한 목적으로 지금까지 연구되어 온 배터리 소모 모델분석 기법들에 대하여 비교 및 평가하고자 한다. 평가 결과를 기반으로 향후 모바일 디바이스 배터리 소모 분석 연구의 발전 방향을 제안한다. The consumption of mobile device batteries which are limited resources is an important criterion when circuit designers analyze and evaluate circuits. For this reason, researchers conducted researches with different models of battery consumption to analyze power consumption of mobile devices. The battery consumption model generation techniques have various characteristics depending on availability of sensors, run-time model generation, and models for using in verification and testing. However, there is lack of comparison and analysis between varied battery consumption model generation methods. In this research, we compare and evaluate the analysis methods which have been studied so far to support the circuit investigation for circuit designers. Finally, we suggest the direction of researches in battery consumption analysis using the comparison result.

실내·외 측위를 위한 Path-Loss Model 기반 거리측정

김량수(Ryangsoo Kim),김인식(Inshick Kim),조치우(Chiwoo Cho),임혁(Hyuk Lim) 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.6

In Situ Dry Etching Processes for Moly Multi - Layers with application to the Reduced Process - Less Mask TFT

MunPyo Hong,Sanggab Kim,Chungi Yu,Seongyun Cho,Jangsoo Kim,Chiwoo Kim,Honggun Yang,Joonhyung Souk 한국진공학회 1997 한국진공학회 학술발표회초록집 Vol.- No.-

Frequency and Quadrature-Amplitude Modulation for Downlink Cellular OFDMA Networks

Hong, Sungnam,Sagong, Min,Lim, Chiwoo,Cho, Sunghye,Cheun, Kyungwhoon,Yang, Kyeongcheol IEEE 2014 IEEE journal on selected areas in communications Vol.32 No.6

<P>The distribution of the intercell interference (ICI) in conventional cellular networks employing orthogonal frequency-division multiple-access (OFDMA) with quadrature-amplitude modulation (QAM) tends to approach a Gaussian distribution when all available subcarriers in each cell are fully loaded. Recently, it has been also shown that the worst-case distribution of the ICI as additive noise in wireless networks with respect to the channel capacity is Gaussian. Thus, the channel capacity in cellular networks is expected to be further enhanced when the ICI could be designed properly so that it has a non-Gaussian distribution. This observation motivates us to propose, in this paper, a downlink cellular OFDMA network employing a modulation scheme called frequency and QAM (FQAM). We also derive maximum-likelihood metrics for the binary or non-binary error-correcting codes employed in the proposed network and propose their practical sub-optimal versions. Numerical results demonstrate that the distribution of the ICI in the proposed network deviates far from the Gaussian distribution. As a result, the transmission rates for the cell-edge users in the proposed network are significantly improved. In addition, the measurement results using practically implemented FQAM-based OFDMA systems verify that the transmission rates for the cell-edge users can dramatically increase, compared with the conventional QAM-based OFDMA network.</P>

반복적인 저혈당으로 엑솜 시퀀싱을 통해 31개월에 진단된 Citrin 결핍증 1례

김치우,황정윤,양아람,김진섭,이태헌,장자현,조성윤,진동규,Kim, Chiwoo,Hwang, Jeongyun,Yang, Aram,Kim, Jinsup,Lee, Taeheon,Jang, Ja-Hyun,Cho, Sung Yoon,Jin, Dong-Kyu 대한유전성대사질환학회 2017 대한유전성대사질환학회지 Vol.17 No.2

Citrin 결핍증은 요소회로 이상 질환 중 하나로, 7q21.3에 위치한 SLC25A13 유전자에 돌연변이로 발생하는 상염색체 열성 유전질환이다. 세 가지 표현형 중에 신생아 간내 담즙 정체형, 제 2형 시트룰린혈증은 잘 알려졌지만, 성장부진과 이상지질혈증형은 최근에 밝혀지고 있는 표현형으로 아직 우리나라에 보고된 적이 없다. 성장부진과 이상지질혈증형에서는 경미할 수는 있으나 식욕감소, 피곤함, 성장부진, 저혈당, 시트룰린 상승, 이상지질혈증, 젖산염/피루브산염 상승과 같은 이상이 관찰될 수 있다. 또한 저혈당으로 내원하였을 때 일반적인 검사로는 원인 규명이 어려울 수 있다. 저자들은 생후 30개월에 반복적인 저혈당으로 내원하여 소변 유기산 분석, 호르몬 검사와 같은 대사 이상 검사에서 명확한 특정 진단명이 의심되지 않아, 생후 31개월에 targeted exome sequencing을 통해 복합이형접합 SLC25A13 유전자 돌연변이[c.852_855del (p.Met285Profs*2), c.1177+1G>A]를 발견하여 성장부진과 이상지질혈증으로 발현한 citrin 결핍증을 우리나라에서 최초로 진단하여 보고하는 바이다. Citrin deficiency is an autosomal recessive disorder caused by mutations in the SLC25A13 gene on chromosome 7q21.3, and a type of urea cycle disorder that causes hyperammonemia. Although neonatal intrahepatic cholestasis and adult-onset type II citrullinemia, a type of citrin deficiency, have been described well in many articles for several decades, failure to thrive and dyslipidemia caused by citrin deficiency (FTTDCD), the other type of citrin deficiency, has been only identified recently. There was previously no case report about FTTDCD in Korea. Patients with FTTDCD could present with loss of appetite, fatigue, failure to thrive, hypoglycemia, hypercitrullinemia, dyslipidemia, and an increased lactate/pyruvate ratio. Routine evaluation may not reveal the cause of hypoglycemia caused by citrin deficiency. We recently had a case that presented with recurrent hypoglycemia in a 30-month-old boy. Chemistry profiling, urine organic acid analysis, plasma acylcarnitine analysis, and hormone studies indicated values within the normal range or non-specific findings. Mutation analysis to identify the cause of hypoglycemia identified the subject as a compound heterozygote carrying each of the c.852_855del ($p.Met285Profs^*2$), and c.1177+1G>A mutant alleles. We report here on this unusual case of citrin deficiency presenting with FTTDCD for the first time in Korea.

First female Korean child with Coffin-Lowry syndrome: a novel variant in RPS6KA3 diagnosed by exome sequencing and a literature review

Song Ari,Im Minji,Kim Min-Sun,Noh Eu Seon,Kim Chiwoo,Jang Jahyun,Lee Sae-Mi,Ki Chang-Seok,Cho Sung Yoon,Jin Dong-Kyu 대한소아내분비학회 2023 Apem Vol.28 No.1

Coffin-Lowry syndrome (CLS, OMIM # 303600) is a rare X-linked disorder caused by mutations in RPS6KA3. CLS is characterized by facial dysmorphism, digit abnormalities, developmental delays, growth retardation, and progressive skeletal changes in male patients. Females with CLS are variably affected, complicating diagnosis. Here, we describe the clinical and molecular findings in a female Korean child with CLS and review the associated literature. A 5-year-old girl presented with short stature and developmental delays. She had a coarse facial appearance characterized by a prominent forehead, hypertelorism, thick lips, and hypodontia. She also had puffy tapering fingers and pectus excavatum. We performed exome sequencing and identified a novel, likely pathogenic, heterozygous variant, c.326_338delinsCTCGAGAC (p.Val109Alafs*10), in RPS6KA3 (NM_004586.2). This is the first Korean female genetically diagnosed with CLS. In contrast to the delayed bone age reported in previous studies, our patient showed advanced bone age and central precocious puberty. CLS should be considered as a differential diagnosis of short stature, tapering fingers, and developmental delay. We suggest that molecular techniques can be a useful tool for diagnosis of rare disorders such as CLS because such conditions are not simple, and the associated spectrum of phenotypes can vary.

Joint Problems in Patients with Mucopolysaccharidosis Type II

Kim, Min-Sun,Kim, Jiyeon,Noh, Eu Seon,Kim, Chiwoo,Cho, Sung Yoon,Jin, Dong-Kyu Association for Research of MPS and Rare Diseases 2021 Journal of mucopolysaccharidosis and rare disease Vol.5 No.1

Hunter syndrome or mucopolysaccharidosis type II (MPS-II) (OMIM 309900) is a rare lysosomal storage disorder caused by deficiency in the activity of the enzyme iduronate-2-sulfatase. This enzyme is responsible for the catabolism of the following two different glycosaminoglycans (GAGs): dermatan sulfate and heparan sulfate. The lysosomal accumulation of these GAG molecules results in cell, tissue, and organ dysfunction. Patients can be broadly classified as having one of the following two forms of MPS II: a severe form and an attenuated form. In the severe form of the disease, signs and symptoms (including neurological impairment) develop in early childhood, whereas in the attenuated form, signs and symptoms develop in adolescence or early adulthood, and patients do not experience significant cognitive impairment. The involvement of the skeletal-muscle system is because of essential accumulated GAGs in joints and connective tissue. MPS II has many clinical features and includes two recognized clinical entities (mild and severe) that represent two ends of a wide spectrum of clinical severities. However, enzyme replacement therapy is likely to have only a limited impact on bone and joint disease based on the results of MPS II studies. The aim of this study was to review the involvement of joints in MPS II.