• Title/Summary/Keyword: KeumCheon

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A 4-Channel Multi-Rate VCSEL Driver with Automatic Power, Magnitude Calibration using High-Speed Time-Interleaved Flash-SAR ADC in 0.13 ㎛ CMOS

  • Cho, Sunghun;Lee, DongSoo;Lee, Juri;Park, Hyung-Gu;Pu, YoungGun;Yoo, Sang-Sun;Hwang, Keum Cheol;Yang, Youngoo;Park, Cheon-Seok;Lee, Kang-Yoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.3
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    • pp.274-286
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    • 2016
  • This paper presents a 4-channel multi-rate vertical-cavity surface-emitting laser (VCSEL) driver. In order to keep the output power constant with respect to the process, voltage, temperature (PVT) variations, this research proposes automatic power and magnitude. For the fast settling time, the high-speed 10-bit time-interleaved Flash-successive approximation analog to digital converter (Flash-SAR ADC) is proposed and shared for automatic power and magnitude calibration to reduce the die area and power consumption. This chip is fabricated using $0.13-{\mu}m$ CMOS technology and the die area is $4.2mm^2$. The power consumption is 117.84 mW per channel from a 3.3 V supply voltage at 10 Gbps. The measured resolution of bias /modulation current for APC/AMC is 0.015 mA.

2.6 GHz GaN-HEMT Power Amplifier MMIC for LTE Small-Cell Applications

  • Lim, Wonseob;Lee, Hwiseob;Kang, Hyunuk;Lee, Wooseok;Lee, Kang-Yoon;Hwang, Keum Cheol;Yang, Youngoo;Park, Cheon-Seok
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.3
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    • pp.339-345
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    • 2016
  • This paper presents a two-stage power amplifier MMIC using a $0.4{\mu}m$ GaN-HEMT process. The two-stage structure provides high gain and compact circuit size using an integrated inter-stage matching network. The size and loss of the inter-stage matching network can be reduced by including bond wires as part of the matching network. The two-stage power amplifier MMIC was fabricated with a chip size of $2.0{\times}1.9mm^2$ and was mounted on a $4{\times}4$ QFN carrier for evaluation. Using a downlink LTE signal with a PAPR of 6.5 dB and a channel bandwidth of 10 MHz for the 2.6 GHz band, the power amplifier MMIC exhibited a gain of 30 dB, a drain efficiency of 32%, and an ACLR of -31.4 dBc at an average output power of 36 dBm. Using two power amplifier MMICs for the carrier and peaking amplifiers, a Doherty power amplifier was designed and implemented. At a 6 dB back-off output power level of 39 dBm, a gain of 24.7 dB and a drain efficiency of 43.5% were achieved.

Dual Bias Modulator for Envelope Tracking and Average Power Tracking Modes for CMOS Power Amplifier

  • Ham, Junghyun;Jung, Haeryun;Bae, Jongsuk;Lim, Wonseob;Hwang, Keum Cheol;Lee, Kang-Yoon;Park, Cheon-Seok;Yang, Youngoo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.802-809
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    • 2014
  • This paper presents a dual-mode bias modulator (BM) for complementary metal oxide semiconductor (CMOS) power amplifiers (PAs). The BM includes a hybrid buck converter and a normal buck converter for an envelope tracking (ET) mode for high output power and for an average power tracking (APT) mode for low output power, respectively. The dual-mode BM and CMOS PA are designed using a $0.18-{\mu}m$ CMOS process for the 1.75 GHz band. For the 16-QAM LTE signal with a peak-to-average power ratio of 7.3 dB and a bandwidth of 5 MHz, the PA with the ET mode exhibited a poweradded efficiency (PAE) of 39.2%, an EVM of 4.8%, a gain of 19.0 dB, and an adjacent channel leakage power ratio of -30 dBc at an average output power of 22 dBm, while the stand-alone PA has a PAE of 8% lower at the same condition. The PA with APT mode has a PAE of 21.3%, which is an improvement of 13.4% from that of the stand-alone PA at an output power of 13 dBm.

Development and Evaluation of a School-based Anger Management Program (SAMP) for Adolescents (학교기반 분노관리 프로그램의 개발 및 효과)

  • Park, Young-Joo;Ryu, Ho-Sihn;Han, Keum-Sun;Kwon, Jung-Hye;Kim, Han-Kyeom;Cho, Yoon-Jung;Kang, Hyun-Cheol;Cheon, Suk-Hee;Yoon, Ji-Won
    • Journal of Korean Academy of Nursing
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    • v.39 no.1
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    • pp.145-156
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    • 2009
  • Purpose: This study was done to develop a school-based anger management program (SAMP) of 4 sessions and examine its effects on the anger, anger expression, psychosomatic responses, psychosocial responses, and immunologic responses in adolescents. Methods: A quasi-experimental study using a nonequivalent control group, pre-post design with repeated measures was used. Chi-square test, t-test, paired t-test, and Fisher's exact test were used to analyze the data. Results: There were no differences between the experimental and control groups in outcome variables except for lymphocytes. However, following additional analyses, statistically significant differences by time point were observed for pain sensitivity, T cell, Helper T (Th) cell, Suppressor (Ts) cell and Natural Killer (NK) cell post-treatment, entrapment and psychosomatic symptoms at the 4-week follow-up, and resilience at the 10-week follow-up for the experimental group. Conclusion: Although some modifications in contents and administration will be required to increase the effectiveness of the program for anger management, SAMP can be used to promote anger management ability in adolescents.

A Study on the "Diagnosis and Treatment of the Postpartum Syndromes[婦人産後脈證幷治]" in "Synopsis of Golden Chamber ("금궤요략.부인산후맥증병치제이십일(婦人産後脈證幷治第二十一)"에 대(對)한 연구(硏究))

  • Lee, Yun-Cheon;Koh, Seung-Wook;Park, Kum-Sook;Jeong, Heon-Young;Keum, Kyoung-Su
    • Journal of Korean Medical classics
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    • v.21 no.1
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    • pp.43-62
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    • 2008
  • After parturition, woman in childbed's health can grow worse. Because when woman in childbed gives birth, Genital organ can be damaged, and lost a lot of blood, and also consume a lot of physical strengths. So, after parturition, woman in childbed is easy to fall in disease if do not take care in health specially. So after parturition, woman in childbed should be careful in stress, sleep, food etc. This thesis described Postpartum Spasm[痙病], Oppressive Feeling and Dizziness[鬱冒], Constipation[便秘], Abdominal Pain[腹痛], Diarrhea[下利], Annoyance[煩亂] and Vomitting Sickness[嘔逆]. Postpartum Spasm[痙病]'s major symptom is rigided body. This disease corresponds to Tetanus in modem medicine, and bacterial infection is assumed for cause. By Oriental medicine, after parturition, when blood is lacking, if patient takes wind, this disease breaks out. Oppressive Feeling and Dizziness[鬱冒]'s major symptom is dizzy head and gloomy eye. After parturition, when blood is lacking, if patient sweats too much and take cold, this disease breaks out. After parturition, if patient consumes a lot of resins of human body, Constipation[使秘] breaks out. There are four causes to Abdominal pain[腹痛]. First, due to deficiency and cold treats by Danggwisaenggangyangyuktang(當歸牛薑羊肉湯). Second, due to stagnation of Gi(氣) treats by Jisiljakyaksan(枳實芍藥散). Third, due to blood stasis treats by Ha-eohyeoltang(下瘀血湯). Fourth, due to lochiorrhea treats by Daeseunggitang(大承氣湯). After parturition, Annoyance[煩亂] and Vomitting Sickness[嘔逆] due to fever of difficiency treat by Jukpidaehwan(竹皮大丸). After parturition, Febrile diarrhea[熱性下利] treats by Baekduonggagamchoagyotang(白頭翁加甘草阿膠湯). This disease is similar with present Bacillary Dysentery. After parturition, Exteroceptive disease due to taking wind treats by Yangdaltang. Due to wind and fever treats by Jukyeoptang(竹葉湯).

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Wound healing effect of regenerated oxidized cellulose versus fibrin sealant patch: An in vivo study

  • Yoon, Hyun Sik;Na, Young Cheon;Choi, Keum Ha;Huh, Woo Hoe;Kim, Ji Min
    • Archives of Craniofacial Surgery
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    • v.20 no.5
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    • pp.289-296
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    • 2019
  • Background: Topical hemostatic agents are used when ligation, electrocauterization, or other conventional hemostatic methods are impractical. Because a hemostatic agent is a foreign body, it can cause foreign body reactions, inflammation, and infections that can interfere with the wound healing process. Therefore, we should select hemostatic agents after considering their effects on wound healing. Here, we compared the effects of hemostatic agents on wound healing in a rectus abdominis muscle defect in rats. Methods: Twelve Sprague Dawley rats were subjected to creation of a $6{\times}6mm$ defect in the rectus abdominis muscle and divided into four groups: control group; group A, Tachosil fibrin sealant patch; group B, Surgicel Fibrillar oxidized regenerated cellulose; and group C, Surgicel Snow oxidized regenerated cellulose. For the histologic analysis, biopsies were performed on the 3rd, 7th, and 27th days. Results: The foreign body reaction was the weakest in group A and most significant in group C. The inflammatory cell infiltration was the weakest in group A and similar in groups B and C. Muscle regeneration differed among periods. The rats in group A were the most active initially, while those in group C showed prolonged activity. Conclusion: Tachosil and Surgicel administration increased inflammation via foreign body reactions, but the overall wound healing process was not significantly affected. The increased inflammation in the Surgicel groups was due to a low pH. We recommend using Tachosil, because it results in less intense foreign body reactions than Surgicel and faster wound healing due to the fibrin action.

Prospective evaluation of the clinical utility of whole-exome sequencing using buccal swabbing for undiagnosed rare diseases

  • Chong Kun Cheon;Yong Beom Shin;Soo-Yeon Kim;Go Hun Seo;Hane Lee;Changwon Keum;Seung Hwan Oh
    • Journal of Genetic Medicine
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    • v.19 no.2
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    • pp.76-84
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    • 2022
  • Purpose: Whole-exome sequencing (WES) has been a useful tool for novel gene discovery of various disease categories, further increasing the diagnostic yield. This study aimed to investigate the clinical utility of WES prospectively in undiagnosed genetic diseases. Materials and Methods: WES tests were performed on 110 patients (age range, 0-28 years) with suspected rare genetic diseases. WES tests were performed at a single reference laboratory and the variants reported were reviewed by clinical geneticists, pediatricians, neurologists, and laboratory physicians. Results: The patients' symptoms varied with abnormalities in the head or neck, including facial dysmorphism, being the most common, identified in 85.4% of patients, followed by abnormalities in the nervous system (83.6%). The average number of systems manifesting phenotypic abnormalities per patient was 3.9±1.7. The age at presentation was 2.1±2.7 years old (range, 0-15 years), and the age at WES testing was 6.7±5.3 years (range, 0-28 years). In total, WES test reported 100 pathogenic/likely pathogenic variants or variants of uncertain significance for 79 out of 110 probands (71.8%). Of the 79 patients with positive or inconclusive calls, 55 (50.0%) patients were determined to have good genotype-phenotype correlations after careful review. Further clinical reassessment and family member testing determined 45 (40.9%) patients to have been identified with a molecular diagnosis. Conclusion: This study showed a 40.9% diagnostic yield for WES test for a heterogeneous patient cohort with suspected rare genetic diseases. WES could be the feasible genetic test modality to overcome the diversity and complexity of rare disease diagnostics.

A Documentational Study on the Development of Chi-Kung-Hak (기공학(氣功學) 발달(發達)에 관한 문헌적(文獻的) 연구(硏究))

  • Kim Woo-Ho;Hong Won-Sik
    • Journal of Korean Medical Ki-Gong Academy
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    • v.1 no.1
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    • pp.13-59
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    • 1996
  • Dep. of Classics &Medical History, College of Oriental Medicint, Kyung Hee University Today, many people are more interested Today, many people are more interested in preventing the disease than curing it. Chi-Kung(氣功) is the way of Life-Cultivation(養生法) peculiar to the orient, it is reported in china that Chi-Kung has an excellent curative value not only in curing the disease but also in preventing it. But the full-scale study of Chi-Kung is not be made up to now in Korea, so I studied the developmental history of chinese Chi-Kung through the oriental medical books. From this study, I reached the following conclusions; 1. Chi-Kung is naturally derived from the self-preservation instinct to adapt oneself to circumstances of the nature, but in the investigation from the documentational records, it is originated in the treatment method of the Sam-Huang-O-Jae(三皇五帝) period to cure the abnormal circulation of the vital force and blood caused by damp(濕). 2. As the principle and the method of the Life-Cultivation of the Chun-Chu-Jeon-Kook(春秋戰國) period were recorded in Huang-Jae-Nai-Gyung(黃帝內經) detailly and the remedy examples by ancient Chi-Kung such as Tao-Yin(導引), Haeng-Chi(行氣) were presented, we considered that theoretical basis of the development of Life-cultivation and Chi-Kung study was furnished in that period. 3. A famous doctor, Hwa-Ta(華引) lived in Han dynasty, researched the theory and practice of Tao-Yin transmitted from the former generations, as that result, he formed a kind of medical, gymnastics what is called O-Keum-Hi(五禽?). It is considered that 'O-Keum-Hi' is a Tao-Yin method developed more practically and systemetically than the Tao-Yin appeared in the 'Jang-Ja'(莊子) or 'Hoy-Nam-Ja'(淮南子). 4. In Wui-Jin-Nambook-Jo(魏曺南北朝) periods, the contents of Chi-Kung were more abundant under the influence of Buddhism(佛敎) and Taoism(道敎). Galhong(葛洪), the author of 'Po-Bak-Ja'(抱朴子) arranged the ancient Chi-Kung method systematically first of all, Tao-Goeng-Gyung, the author of 'Yang-Seong-Yeun-Myung-Rok'(養性延命錄) recorded the 'Yook-Ja-Geul'(六字訣) first time. 5. There is a new development of Chi-Kung therapy in Soo-Tang-Odae(隋唐五代) periods, especially So-Won-Bang(巢元方), the author of 'Jey-Bang-Won-Hwu-Ron' collected almost all of the Chi-Kung method, for curing the disease formed before Soo(隋) period. From that fact, we supposed that Chi-Kung was utilized more widely in curing the disease. 6. 'So-Ju-Cheon-Hwa-Hu-Peob'(小周天火候法) was adopted as the best orthodox approach under the influence of Nae-Tan-Taoist(道敎內丹學波) in Song-Keum-Won(宋金元) periods, especially in the song dynasty, 'Pal-Dan-Geum'(八段錦) was appearde and assignment of six-Chi(六氣) for bowel and viscera in the 'Yook-Ja-Geul'(六字訣) was decided firmly, that is to say Lung-Si(肺-?), Heart-Kha(心-呵), Spleen-Hoa(脾-呼), liver-Hoe(肝-噓), Kidney-chui(賢-吹), Three-Burner-shi(三焦-?). 7. In Myung-Cheong(明淸) periods, The general practitioner applied the principle of 'Byun-Jeng-Ron-Chi(辨證論治) to the Chi-Kung field, and after Myung dynasty the style of doing 'Yook-Ja-Gyel'(六字訣) was developed to the moving style. 8. Today, in china, the study on the Chi-Kyung is being progressed constantly under the positive assistance of government, Chi-Kung-Hak(氣功學) has taking its place as a branch of study step by step. It is considered that the establishment of Chi-Kung-Hak Classroom(氣功學敎室) and Medical Chi-Kung Center(氣功療法室) for special and systematic research are needed, at the same time the settlement of institutional system for training the Chi-Kung technician(氣功師) is also needed.

A Documentational Study on the Development of Chi-Kung-Hak (기공학(氣功學) 발달(發達)에 관한 문헌적(文獻的) 연구(硏究))

  • Kim, Woo Ho;Hong, Won Sik
    • Journal of Korean Medical classics
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    • v.4
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    • pp.19-73
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    • 1990
  • Today, many people are more interested in preventing the disease than curing it. Chi-Kung (氣功) is the way of Life-Cultivation (養生法) peculiar to the orient, it is reported in china that Chi-Kung has an excellent curative value not only in curing the disease but also in preventing it. But the full-scale study of Chi-Kung is not be made up to now in Korea, so I studied the developmental history of chinese Chi-Kung through the oriental medical books. From this study, I reached the following conclusions ; 1. Chi-Kung is naturally derived from the self-preservation instinct to adapt oneself to circumstances of the nature, but in the investigation from the documentational records, it is originated in the treatment method of the Sam-Huang-O-Jae (三皇五帝 )period to cure the abnormal circulation of the vital force and blood caused by damp (濕). 2. As the principle and the method of the Life-Cultivation of the Chun-chu-Jeon-Kook (春秋戰國) periods were recorded in Huang-Jae-Nai-Gyung (黃帝內徑) detailly and the remedy examples by ancient Chi-Kung such as Tao-Yin (導引), Haeng-Chi (行氣) were presented, we considered that theoretical basis of the development of Life-cultivation and Chi-Kung study was furnished in that period. 3. A famous doctor, Hwa-Ta (華陀) lived in Han dynasty, researched the theory and practice of Tao-Yin transmitted from the former generations, as that result, he formed a kind of medical gymnastics what is called O-Keum-Hi (五禽戱). It is considered that 'O-Keum-Hi' is a Tao-Yin method developed more practically and systemetically than the Tao-Yin appeared in the 'Jang-Ja' (莊子) or 'Hoy-Nam-Ja' (淮南子). 4. In Wui-Jin-Nambook Jo (魏晋南北朝) periods, the contents of Chi-Kung were more abundant under the influence of Buddhism (佛敎) and Taoism (道敎). Galhong (葛洪), the author of 'Po-Bak-Ja' (抱朴子) arranged the ancient Chi-Kung method systematically first of all, Tao-Goeng-Gyung (陶宏景), the author of 'Yang-Seong-Yeun-Myung-Rok' (養性延命錄) recorded the 'Yook-Ja-Geul' (六字訣) first time. 5. There is a new development of Chi-Kung therapy in Soo-Tang-Odae (隋唐五代) pefiods, especially So-Won-Bang (巢元方), the author of 'Jey-Byung-Won-Hwu-Ron' (諸病源候論) collected aimost all of the Chi-Kung method, for curing the disease formed before soo (隋) period. From that fact, we supposed that Chi-Kung was utilized more widely in curing the disease. 6. 'So-Ju-Cheon-Hwa-Hu-Peob' (小周天火候法) was adopted as the best orthodox approach under the influence of Nae-Tan-Taoist (道敎內丹學派) in Song-Keum-Won (宋金元) periods, especially in the song dynasty, 'Pal-Dan-Geum' (八段錦) was appeared and assignment of six-Chi (六氣) for bowel and viscera in the 'Yook-Ja-Geul' (六字訣) was decided firmly, that is to say Lung-Si (肺-呬), Heart-Kha (心-呵), Spleen-Hoa (脾-呼), Liver-Hoe (肝-噓), Kidneychui (賢-吹), Three-Burner-shi (三焦-嘻). 7. In Myung-Cheong (明淸) periods, The general practitioner applied the principle of 'Byun-Jeng-Ron-Chi' (辨證論治) to the Chi-Kung field, and after Myeong dynasty the style of doing 'Yook-Ja-Gyel' (六字訣) was developed to the moving style. 8. Today, in china, the study on the Chi-Kung is being progressed constantly under the positive assistance of government, Chi-Kung-Hak (氣功學) has taking its place as a branch of study step by step. It is considered that the establishment of Chi-Kung-Hak Classroom (氣功學教室) and Medical Chi-Kung Center (氣功療法室) for special and systematic research are needed, at the same time the settlement of institutional system for training the Chi-Kung technician (氣功師) is also needed.

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Comparision of Physical Habitat Suitability Index for Fishes in the Rivers of Han and Geum River Watersheds (한강 및 금강수계 하천에서 어류의 물리서식처 적합도지수 비교)

  • Kang, Hyeongsik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1B
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    • pp.71-78
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    • 2012
  • The habitat suitability is an important factor to estimate the distribution and size of the physical habitat in river. This suitability is also a key factor to decide the ecological flow discharge for the fish. For the ecological analysis in river, accurate values of habitat suitability index for various fishes are necessary. In general, fish habitat is affected by the physical factor of the flow depth and velocity as well as the chemical and biological factors of nutrient and attached algae. Thus, the condition of the fish habitat is expected to be changed with each watershed and tributary. In this study, the habitat suitability indices for fishes were proposed by using the field monitoring data in the rivers of the Han and Geum river watersheds. The proposed indices for three fishes are compared: Zacco platypus, Zacco temminckii, and Coreoleuciscus splendidus. The results show that Zacco platypus has a similar distribution of habitat suitability index in two watersheds. Zacco temminckii and Coreoleuciscus splendidus, however, have different distributions with watersheds. Also, for Zacco platypus, the developed indices at three tributaries of the Han river are compared: Cheng-mi stream, Dal stream, and Hong-cheon stream. The comparision shows that the index in the Cheng-mi stream is different with those in the other rivers. This is expected to be because of a high nutrient concentration at the Cheong-mi stream.