환율 변동성 예측 모형의 실증분석 -원/달러 환율을 중심으로-

최생림 ( Sang Rim Choi ),형남원 ( Nam Won Hyung ) 한국국제경영학회 2003 國際經營硏究 Vol.14 No.1

Various volatility forecasting models were tested and compared using shor-term and long-term Korean won/US dollar exchange rates. EWMA model, like in other previous research, shows better estimates than GARCH-type time series models in short-term. In long-term analysis, the relative dominance of EWMA model decays rapidly and the power of FIGARCH model, among other GARCH models, proves to be superior due to its long memory reflecting mechanism.

오공약침의 안전성에 대한 임상적 연구

소기숙,최회강,박소영,고강훈,김성남,이옥자,윤민영,문형철,김성철,이정훈,나원경,So, Ki-suk,Choi, Hoi-kang,Park, So-young,Koh, Kang-hun,Kim, Sung-nam,Lee, Ok-ja,Yun, Min-young,Mun, Hyung-chul,Kim, Sung-chul,Lee, Jung-hun,Na, Won-kyung 대한침구의학회 2004 대한침구의학회지 Vol.21 No.1

Objective: Recently scolopendrid aquacupuncture has been a good effect on pain control but it has not been known about clinical safety. So, In order to prove the clinical safety of scolopendrid aquacupuncture, We have observed the physical reac-tion and clinical pathology test after scolopendrid aquacupuncture treatment. Methods: We analyzed physical reaction and clinical pathology test before and after Scolopendrid aquacupuncture treatment of 30 patients suffering from pain, who admitted department of Acupunture and Moxibustion, College of Oriental Medicine, Won-Kwang University Kwangju hospital. Results & Conclusions: The results were summarized as follows. 1) The distribution of sex was 14 males and 16 females, and the average of patients age was 46.2 years. 2) The distribution of symptom was lumbago, lumbago with radiating pain, nuchal pain and knee joint pain. 3) In the 30 patients treated with Scolopendrid aquacupuncture, hematologic test did not show remarkable change. 4) In the 30 patients treated with Scolopendrid aquacupuncture, Liver function test(AST, ALT, ALP) showed a slight decrease on the contrary, and abnormal rate showed a decrease of 1.0%(from 3.3% to 2.3%) compared with previous study. 5) In the 30 patients treated with Scolopendrid aquacupuncture, Renal function test(BUN, Cr) and abnormal rate(from 2.5% to 2.0%) showed a slight decrease on the contrary. 6) In the 30 patients treated with Scolopendrid aquacupuncture. Electrolyte were normal range before & after treatment. 7) In the results of the Urine analysis of 30 patients, Leukocyte, Protein. Glucose, Keton, Bilirubin, U-bilinogen were not detected before and after Scolopendrid aquacupuncture treatment, and the rest almost made no difference. 8) In the Physical reactions, all of the patients complained of pain of body partially, only one patient showed reddish and itch, but symptoms like those were entirely disappeared within 24 hours and whole body pain, swelling, headache, dizziness, fatigue and nausea was not observed.

Retrospective evaluation of toceranib phosphate (Palladia) for treatment of different tumor types in 31 dogs

Choi, Seo-In,Nam, Ye-Lim,Kim, Jin-Kyoung,Park, Hyung-Jin,Song, Kun-Ho,Seo, Kyoung Won The Korean Society of Veterinary Science 2021 大韓獸醫學會誌 Vol.61 No.1

The purpose of this retrospective study was to provide additional data on the use of toceranib in a wide variety of tumor types in small breed dogs, especially < 8 kg (except 5 dogs). This was a retrospective study of 31 dogs with malignant tumors treated with a 2.5 mg/kg median dose of toceranib (Palladia; Zoetis, USA) on a Monday-Wednesday-Friday schedule. Clinical benefit was observed in 13 of 15 dogs (86.7%, 3 with complete response, 4 with partial response, 6 with stable disease) with gross disease. Distant metastasis, response to treatment, and treatment setting were significantly associated with survival time. Negative prognostic factors were multiple chemotherapy and distant metastasis (affecting progression-free survival [PFS]), surgery, regional enlarged lymph nodes, underlying disease, and toxicity (affecting median survival time [MST]). Positive prognostic factors were epithelial and round cell tumor (affecting PFS), epithelial tumor, microscopic disease, no evidence of disease response, and stable disease (MST). In conclusion, a clinical benefit from toceranib treatment was noted in most of the dogs with gross disease in our study. This study suggested that the toceranib is probably selective treatment to various tumor types in small breed dogs.

Morphological Changes by Submerged Culture Conditions for the Mycelial Optimal Growth of Cordyceps sinensis and Immunological Properties of Hot Water Extract of Mycelium

Hyung Joo Suh(서형주),Jang Won Choi(최장원) 한국생물공학회 2010 KSBB Journal Vol.25 No.1

The mycelial dispersed growth of Cordyceps sinensis was optimized in submerged batch culture at initial pH of 5.0, 150 rpm, and 25℃. The morphological data showed much more dispersed growth of C. sinenesis at initial pH of 5.0. Also, projected area, main hyphal length and number of tips for the mycelial growth of initial pH 5.0 were higher than those of other initial pHs. The industrial medium for mycelial production of C. sinensis was determined to be molasses of 100 g and crushed brewery yeast of 10 g per liter as carbon and nitrogen sources, respectively. With these culture conditions, the maximum production of mycelia was approximately 30.0 g per liter by batch culture in 5-liter jar fermenter with no controlled pH. This result suggests that large-scale mycelia production of C. sinensis may be possible in submerged batch culture. The hot water extract of mycelia from C. sinensis was mainly composed of 83.0% carbohydrate, 11.8% protein, 1.9% lipid, and 2.4% ash and there were present glucose, mannose, galactose, and arabinose as molar ratio of 8.79 2.59:1.34:1.0 in the carbohydrate, respectively. In the experiment using spleen cell and macrophage, the extract showed potent mitogenic and immuno-stimulating activities and among various components, an important factor that contribute to the immunological activities was turned out to be carbohydrate moiety.

Molecular Mechanism of Tetrabromobisphenol A (TBBPA)-induced Target Organ Toxicity in Sprague-Dawley Male Rats

Choi, Jae-Seok,Lee, Young-Jun,Kim, Tae-Hyung,Lim, Hyun-Jung,Ahn, Mee-Young,Kwack, Seung-Jun,Kang, Tae-Seok,Park, Kui-Lea,Lee, Jae-Won,Kim, Nam-Deuk,Jeong, Tae-Cheon,Kim, Sang-Geum,Jeong, Hye-Gwang,Lee Korean Society of ToxicologyKorea Environmental Mu 2011 Toxicological Research Vol.28 No.2

Brominated flame retardants (BFRs) are present in many consumer products ranging from fabrics to plastics and electronics. Wide use of flame retardants can pose an environmental hazard, which makes it important to determine the mechanism of their toxicity. In the present study, dose-dependent toxicity of tetrabromobisphenol A (TBBPA), a flame retardant, was examined in male prepubertal rats (postnatal day 18) treated orally with TBBPA at 0, 125, 250 or 500 mg/kg for 30 days. There were no differences in body weight gain between the control and TBBPA-treated groups. However, absolute and relative liver weights were significantly increased in high dose of TBBPA-treated groups. TBBPA treatment led to significant induction of CYP2B1 and constitutive androstane receptor (CAR) expression in the liver. In addition, serum thyroxin (T4) concentration was significantly reduced in the TBBPA treated group. These results indicate that repeated exposure to TBBPA induces drug-metabolising enzymes in rats through the CAR signaling pathway. In particular, TBBPA efficiently produced reactive oxygen species (ROS) through CYP2B1 induction in rats. We measured 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in the kidney, liver and testes of rats following TBBPA treatment. As expected, TBBPA strongly induced the production of 8-OHdG in the testis and kidney. These observations suggest that TBBPA-induced target organ toxicity may be due to ROS produced by metabolism of TBBPA in Sprague-Dawley rats.

Performance Analysis of the Robust Least Squares Target Localization Scheme using RDOA Measurements

Choi, Ka-Hyung,Ra, Won-Sang,Park, Jin-Bae,Yoon, Tae-Sung The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.4

A practical recursive linear robust estimation scheme is proposed for target localization in the sensor network which provides range difference of arrival (RDOA) measurements. In order to radically solve the known practical difficulties such as sensitivity for initial guess and heavy computational burden caused by intrinsic nonlinearity of the RDOA based target localization problem, an uncertain linear measurement model is newly derived. In the suggested problem setting, the target localization performance of the conventional linear estimation schemes might be severely degraded under the low SNR condition and be affected by the target position in the sensor network. This motivates us to devise a new sensor network localization algorithm within the framework of the recently developed robust least squares estimation theory. Provided that the statistical information regarding RDOA measurements are available, the estimate of the proposition method shows the convergence in probability to the true target position. Through the computer simulations, the omnidirectional target localization performance and consistency of the proposed algorithm are compared to those of the existing ones. It is shown that the proposed method is more reliable than the total least squares method and the linear correction least squares method.

Comparative Analysis of Patterns of Care Study of Radiotherapy for Esophageal Cancer among Three Countries

Won Joo Hur(허원주),Youngmin Choi(최영민),Jeung Kee Kim(김정기),Hyung Sik Lee(이형식),Seok Reyol Choi(최석렬),Il Han Kim(김일한) 대한방사선종양학회 2008 Radiation Oncology Journal Vol.26 No.2

목 적: 식도암의 방사선 치료에 대해 최초로 시행한 한국의 PCS의 결과를 토대로 미국, 일본에서 시행한 결과와 비교 분석하여 식도암 환자들의 특징, 진단 및 치료방침의 차이를 파악해 향후 범 국가적으로 활용할 시스템의 구축에 응용 하고자 하였다. 대상 및 방법: 국내의 21개 병원의 방사선 종양학과에서 1998-1999년 동안 식도암으로 확진 된 후 방사선 치료를 받은 총 246명을 대상으로 하였다. 이 결과를 미국 59개 병원에서 식도암 환자 414명을 연구한 PCS 결과 (Suntharalingam)와 비교 하였다. 또 일본의 76개 병원에서 수술과 방사선치료를 받았거나 수술, 방사선 치료, 항암제 치료를 함께 받은 수술 군 환자 220명(Gomi), 수술을 받지 않고 방사선 치료만 시행하였거나 방사선 치료와 항암제치 료를 함께 시행한 비 수술 군 환자 385명(Murakami)을 대상으로 시행한 PCS 결과와 비교 분석하였다. 결 과: 환자들의 평균 연령은 일본의 비 수술 군이 가장 높았다(71세). 한국과 일본은 남성의 발생 빈도가 월등히 높았지만(9:1) 미국은 여성의 발생률이 23.1%였다. 한국과 일본은 편평상피세포암이 압도적으로 많았지만(한국 96.3%,일본 98%) 미국은 선암이 더 많은 양상을 보였다(49.6%). 병기결정을 위한 검사는 식도 내시경, 흉부 컴퓨터 단층촬영, 식도조영술을 가장 많이 사용하였고 미국과 일본은 복부 컴퓨터단층촬영을 복부 초음파보다 더 자주 시행하였다. 치료방침을 분석한 결과 방사선 단독치료의 비율은 한국이 23.2%, 일본이 39%인데 반해 미국은 9.5%에 불과하였다. 수술과 방사선 및 항암치료를 병용한 빈도는 미국(32.8%)과 일본 (49.5%)이 한국(11.8%)보다 높았다. 식도암 치료에 있어서 항암제 치료는 미국이 가장 높은 빈도로 사용되어졌고(89%) 동시항암방사선 치료도의 빈도도 미국이 가장 높았다(97%). 항암치료제는 3개국 모두에서 cisplatin과 5-FU를 가장 선호하였다. 방사선 조사량은 한국 55.8 Gy, 미국 50.4 Gy였고 일본은 수술 군(48 Gy)과 비 수술 군(60 Gy)이 현격한 차이를 보였다. 결 론: 한국, 미국, 일본에서 시행된 식도암 환자의 PCS 결과를 분석하여 환자 및 종양의 특징, 진단 및 치료 방침에 다소간의 상이점을 발견하였다. 그러나 방사선 조사량과 조사야 수, 방사선치료 에너지의 종류 등 방사선 기술적인 부분은 3개국 모두에서 큰 차이를 보이지 않았다. Purpose: For the first time, a nationwide survey of the Patterns of Care Study (PCS) for the various radiotherapy treatments of esophageal cancer was carried out in South Korea. In order to observe the different parameters, as well as offer a solid cooperative system, we compared the Korean results with those observed in the United States (US) and Japan. Materials and Methods: Two hundreds forty-six esophageal cancer patients from 21 institutions were enrolled in the South Korean study. The patients received radiation theraphy (RT) from 1998 to 1999. In order to compare these results with those from the United States, a published study by Suntharalingam, which included 414 patients [treated by Radiotherapy (RT)] from 59 institutions between 1996 and 1999 was chosen. In order to compare the South Korean with the Japanese data, we choose two different studies. The results published by Gomi were selected as the surgery group, in which 220 esophageal cancer patients were analyzed from 76 facilities. The patients underwent surgery and received RT with or without chemotherapy between 1998 and 2001. The non-surgery group originated from a study by Murakami, in which 385 patients were treated either by RT alone or RT with chemotherapy, but no surgery, between 1999 and 2001. Results: The median age of enrolled patients was highest in the Japanese non-surgery group (71 years old). The gender ratio was approximately 9:1 (male:female) in both the Korean and Japanese studies, whereas females made up 23.1% of the study population in the US study. Adenocarcinoma outnumbered squamous cell carcinoma in the US study, whereas squamous cell carcinoma was more prevalent both the Korean and Japanese studies (Korea 96.3%, Japan 98%). An esophagogram, endoscopy, and chest CT scan were the main modalities of diagnostic evaluation used in all three countries. The US and Japan used the abdominal CT scan more frequently than the abdominal ultrasonography. Radiotherapy alone treatment was most rarely used in the US study (9.5%), compared to the Korean (23.2%) and Japanese (39%) studies. The combination of the three modalities (Surgery+RT+Chemotherapy) was performed least often in Korea (11.8%) compared to the Japanese (49.5%) and US (32.8%) studies. Chemotherapy (89%) and chemotherapy with concurrent chemoradiotherapy (97%) was most frequently used in the US study. Fluorouracil (5-FU) and Cisplatin were the most preferred drug treatments used in all three countries. The median radiation dose was 50.4 Gy in the US study, as compared to 55.8 Gy in the Korean study regardless of whether an operation was performed. However, in Japan, different median doses were delivered for the surgery (48 Gy) and non-surgery groups (60 Gy). Conclusion: Although some aspects of the evaluation of esophageal cancer and its various treatment modalities were heterogeneous among the three countries surveyed, we found no remarkable differences in the RT dose or technique, which includes the number of portals and energy beams.

Distributed processing of a GPS receiver network for a regional ionosphere map

Choi, Kwang Ho,Lim, Joon Hoo,Yoo, Won Jae,Lee, Hyung Keun IOP Pub 2018 Measurement science & technology Vol.29 No.1

<P>This paper proposes a distributed processing method applicable to GPS receivers in a network to generate a regional ionosphere map accurately and reliably. For accuracy, the proposed method is operated by multiple local Kalman filters and Kriging estimators. Each local Kalman filter is applied to a dual-frequency receiver to estimate the receiver’s differential code bias and vertical ionospheric delays (VIDs) at different ionospheric pierce points. The Kriging estimator selects and combines several VID estimates provided by the local Kalman filters to generate the VID estimate at each ionospheric grid point. For reliability, the proposed method uses receiver fault detectors and satellite fault detectors. Each receiver fault detector compares the VID estimates of the same local area provided by different local Kalman filters. Each satellite fault detector compares the VID estimate of each local area with that projected from the other local areas. Compared with the traditional centralized processing method, the proposed method is advantageous in that it considerably reduces the computational burden of each single Kalman filter and enables flexible fault detection, isolation, and reconfiguration capability. To evaluate the performance of the proposed method, several experiments with field collected measurements were performed.</P>

Reassessing the significance of the <i>PAH</i> c.158G>A (p.Arg53His) variant in patients with hyperphenylalaninemia

Choi, Rihwa,Lee, Jeongho,Park, Hyung-Doo,Park, Jong Eun,Kim, Yong Hyuk,Ki, Chang-Seok,Lee, Soo-Youn,Song, Junghan,Kim, Jong-Won,Lee, Dong Hwan De Gruyter 2017 Journal of pediatric endocrinology & metabolism Vol.30 No.11

<P>Background: The accurate interpretation of sequence variation is critical for successful molecular diagnoses. It is also fundamental to the accurate diagnosis and treatment of phenylketonuria (PKU). This study aims to evaluate the significance of the c.158G > A (p.Arg53His) variant in the PAH gene, which was previously reported to be a pathogenic mutation that results in decreased phenylalanine hydroxylase enzyme activity in hyperphenylalaninemia (HPA) patients. Methods: Seven unrelated Korean patients with HPA genotyped with the c.158G > A variant were included in this study. The variant c.158G > A was classified by the standards and guidelines for the interpretation of sequence variants by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Results: By both directly collecting genetic data and comprehensively reviewing the existing literature, we found that this variant is more appropriately classified as 'Likely benign' rather than pathogenic. The allele's frequency is 2.57% in the general Korean population, which was greater than expected for phenylketonuria. This variant was observed to be homozygous in healthy subjects and was also observed in cis with other pathogenic variants. It is common in East Asian populations (especially in Koreans) compared to Western populations. There is a possibility that it causes decreased enzyme activity without leading to the full pathology of phenylketonuria. Conclusions: This study expands our understanding of the consequences of variation in PAH and its relationship to HPA.</P>

Microcystic Lymphatic malformation and Linear port wine stain in patients with Noonan syndrome(초)

( Hyung Min Lee ),( Seung Phil Hong ),( Chong Hyun Won ),( Sung Eun Chang ),( Mi Woo Lee ),( Jee Ho Choi ),( Kee Chan Moon ) 대한피부과학회 2010 초록집 Vol.48 No.10