The modified Yule-Walker method for multidimensional infinite-variance periodic autoregressive model of order 1

Giri Prashant,Grzesiek Aleksandra,Żuławiński Wojciech,Sundar S.,Wyłomańska Agnieszka 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.2

The time series with periodic behavior, such as the periodic autoregressive (PAR) models belonging to the class of the periodically correlated processes, are present in various real applications. In the literature, such processes were considered in different directions, especially with the Gaussian-distributed noise. However, in most of the applications, the assumption of the finite-variance distribution seems to be too simplified. Thus, one can consider the extensions of the classical PAR model where the non-Gaussian distribution is applied. In particular, the Gaussian distribution can be replaced by the infinite-variance distribution, e.g. by the α-stable distribution. In this paper, we focus on the multidimensional α-stable PAR time series models. For such models, we propose a new estimation method based on the Yule-Walker equa-tions. However, since for the infinite-variance case the covariance does not exist, thus it is replaced by another measure, namely the covariation. In this paper we propose to apply two estimators of the covariation measure. The first one is based on moment representation (moment-based) while the second one—on the spectral measure representation (spectral-based). The validity of the new approaches are verified using the Monte Carlo simulations in different contexts, including the sam-ple size and the index of stability of the noise. Moreover, we compare the moment-based covariation-based method with spectral-based covariation-based technique. Finally, the real data analysis is presented.

각종 갑상선 질환이 요중 17 - Ketosteroids, 17 - Hydroxycorticosteroids 및 Pituitary Gonadotropin배설과 Thorn Test 성적에 미치는 영향에 관한 연구

정원영(WY Chung) 대한산부인과학회 1965 Obstetrics & Gynecology Science Vol.8 No.5

The influences of various thyroid function states on the adreno-cortical functions were strdied through the measurement of the urinary excretion of 17-Ketosteroids, 17-Hydroxycorticosteroids and pituitary gonadotropin. The Thron test was also carried out with the intramuscular injection of 25 mg of ACTH and the changes in the circulating eosinophil cell count, urinary excretion of 17-KS and 17-OHCS were also evaluated. The materials selected were 96 female patients with various thyroid diseases, namely, 41 hyperthyroid, 29 euthyroid and 12 hypothyroid. The follow up studies were done in 13 hyperthyroid and 6 hypothyroid patients after the appropriate treatment. Following were the results: 1) The mean values of 24 hr excretion of urinary 17-KS were: 11, 11±2.97mg in euthyroid, 10.18 ±3.14mg in hyperthyroid, and 7.01±2.68mg in hypothyroid groups respectively. Thus the excretion of urinary 17-KS showed a slightly lower in hyper-, and a markedly lower in hypothyroidism. The mean values of 24 hr excretion of urinary 17-OHCS were: 0.72±0.25mg in euthyroid, 0.81±0.29mg in hyperthyroid, and 0.44±0.16mg in hypothyroid groups respectively. Thus the excretion of urinary 17-OHCS showed a slightly higher in gyper-, and lower in hypothyroidsim. 2) The follow up studies revealed statistically significant differences between the values before and after the treatment. In hyperthyroidism, the 24 hr excretion of urinary 17-KS were 10.17±2.86 before, and 11.70±3.28mg after the treatment, while the 24 hr excretion of urinary 17-OHCS were 1.16±0.28 mg before, and 0.82±0.27mg after the treatment. In hypothyoidism, the 24 hr excretion of urinary 17 KS were 5.34±2.06mg before, and 7.75±3.18mg after the treatment, while the 24 hr excretion of urinary 17-OHCS were 0.34±0.08mg before, and 0.65±0.33mg after treatment. 3) The 24 hr excretion of urinary 17-KS and 17-OHCS were also determined before and after the intramuscular injection of 25mg of ACTH. In euthyroidism, the 17-KS values were 11.27±2.04mg before and 13.44±1.46mg after ACTH, while the 17-OHCS values were 0.68±0.23mg before, and 0.96±0.20mg after ACTH. In hyperthyroidsism the 17-KS values were 9.26±3.48mg before and 10.70±2.23mg after ACTH, while the 17-OHCS values were 0.78±0.23mg before, and 0.93±0.25mg after ACTH. In hypothyroidism, the 17-KS values were 4.99±2.44mg begore, and 5.86±3.39mg after ACTH while the 17-OHCS value were 0.35+0.07mg before, and 0.58+0.28mg after ACTH. Thus the reponses to the 17-OHCS balues were 0.35±0.07mg before, and 0.58±0.28mg after ACTH. Thus the responses to the 17-OHCS values were 0.35±0.07mg before, and 0.58±0.28mg after ACTH. Thus the responses to ACTH were: adequate in euthyroid, inadequate in hyperthyroid and significant in hypothyroid. 4) The eosinophil cell counts after the intramuscular injection of 25mg of ACTH showed a marked decrease in eu-, and hyperthyroid group, while an inadequate response in hypothyroid group, which, however, showed the normal responses after the treatment. 5) The excretion of urinary pituitary gonadotropin were in normal range in eu-, and hyperthyroid groups, while a very low values in some myxedema patients along with the lower values of 17-KS and 17-OHCS, which, however, also returned to normal range after the treatment.

자궁근종에서 발생한 자궁평활근육종의 1예

손위익(WY Sohn),최준영(JY Choe),최형달(HD Choe),남태현(TH Nam) 대한산부인과학회 1973 Obstetrics & Gynecology Science Vol.16 No.3

자궁근종에서 발생한 자궁평활근육종의 1예를 보고하는 바이다. The sarcomatous changes of uterine myoma is a rare entity. A case of leiomyosarcoma regarded to originate from uterine myoma, observed in 28 years old nulliparous housewife, is presented and the literature is reviewed. The diagnosis was made by postoperative routine biopsy of operative specimen. The patient was treated by total abdominal hysterectomy, and a subsequent salpingo-oophorectomy was not performed, and she has been healthy with regular activity until now.

산아손실을 중심으로한 쌍태아임신의 임상적 고찰

정원영(WY Chung),백성현(SH Baik),문재훈(ZH Moon) 대한산부인과학회 1965 Obstetrics & Gynecology Science Vol.8 No.3

It is reported that the perinatal mortality in twinpregnancy is high, and that the second twin is lost more often than the first. In the present study, we submitted for analysis 101 cases of twin pregnancy admitted to Obstetric Ward, N.M.C. among 5,687 deliveries from January 1959 to the end of 1964. Total number of perinatal deaths was 25, excluding 8 of less than 28 weeks gestation. The perinatal mortality was 127, per 1,000 deliveries. We summerized the result as follows: 1) There were eighteen primigravida and eighty-three multipara. Primigravida have a slightly higher rate of fetal mortality than multipara. 2) Birth weight of the infants was closely related to the main cause of death in each case. One hundred percent of fetal loss occurred in infants weighing under 1,000gm, whereas the fetal loss among 1,000-2,000 group was 43.8% of the first twin and 34.8% of the second one, and 7.9% of the first, 10.0% of the second respectively among the group 2.000-2,500g. In the group weighing more than 2,500 g, the fetal loss was 2.3% of the 1st twin, and 7.1% for the second twin group. The critical birth weight in connection with fetal loss would appear to be 2,000 g. 3) As to the time interval between delivery of the first and the second infant in our series, two thirds of the second twin were delivered within 30 minutes with 12.8% mortality. However, fetal mortality of the second twin was 100% after 60 minutes in 3 cases. 4) In 51 registered cases, 4(7.8%) cases were diagnosed for twins after the first twin was delivered. In 50 unregistered cases, 10(20%) cases were diagnosed after the first twin. The importance of diagnosing the presence of the second twin before administering any oxytotic drug cannot be over emphasized. On 3 occasions where such drugs were administered, both the second infants subsequently died. 5) If 10.0g/100ml hemoglobin is used as a tentative borderline value for anemia of 51 registered cases, only 10 were anemic, while 31 of unregistered cases had moderate or severe anemia. 6) Twenty-one cases were under care for toxemia among 51 of registered cases. and 24 in 50 unregistered. There were no evidence of eclampsia in the registered cases. whereas 6 of the unregistered toxemic patients had eclamptic fit. 7) The fetal loss of second twin showed slightly high mortality rate in breech than cephalic delivery in ourseries. In two cases in our series, total hysterectomy was carried out due to atonic bleeding. There were 4 cases of congenital anomalies: thoracopagus, anencephalus and heart anomaly.

Endoscopic Management of Peptic Ulcer Bleeding: Recent Advances

Philip WY Chiu 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.5

Bleeding peptic ulcers remained as one of the commonest causes of hospitalization worldwide. While endoscopic hemostasis serves asprimary treatment for bleeding ulcers, rebleeding after endoscopic hemostasis becomes more and more diffcult to manage as patientsare usually poor surgical candidates with multiple comorbidities. Recent advances in management of bleeding peptic ulcers aimed tofurther reduce the rate of rebleeding through—(1) identification of high risk patients for rebleeding and mortality; (2) improvement inprimary endoscopic hemostasis and; (3) prophylactic angiographic embolization of major arteries. The technique and clinical evidencesfor these approaches will be reviewed in the current article.

진행된 자궁경부암의 박탈상피세포상

손유익(WY Sohn),안종호(JH Ahn),이태호(TH Lee) 대한산부인과학회 1975 Obstetrics & Gynecology Science Vol.18 No.7

In order to determine the possibilily of occurance of false negative cases, the cytogram was studied on 30 cases of advanced Ca. Of the uterine cervix who visited the cancer center of Kyungbook National University Hospital Taegu, Korea from Oct. 1, 1972 to Sep 30, 1973. In this study randomly seleteced 39 cases of ca in situ of the uterine cervix diagnosed by surgical specimen, who visited same institution during Jan. 1, 1972 to Sep.30, 1973 served as control from comparison and the following results were obatined. The difference of false negative rate between vaginal pool smear and cervical scraping smear of advnaced Ca. of the cervix was insighnificant. Only minimal difference was noted between advanced Ca. and Ca. in situ of the uterine cervix. Regarding exfoliated number of dyskaryotic cells no difference was noted between both smear method of advanced Ca. Of the uterine cervix. On the other hand marked increment was noted on Ca. in situ of the cervix. The incidence of a case which showed exfoliation of benign cells over 500, in 36 cases out of 39 cases Ca. in situ and 2 cases out of 30 cases of advanced Ca. of the cervix were 92.3% and 6.7% respectively. the difference being statistically sighnificant. Concerning the rate of exfoliated malignant cells, marked difference was noted between Ca. in situ and advanced Ca. of the uterine cervix in the group of 0.1% to 1.0% and about dyskaryotic and benign cells no case was found both more than 30.1% group and less than 50.0% of Ca. in situ of uterine cervix respectively. Both advanced Ca and in situ of the uterine cervix the most frequent combination found in exfoliated rate of each cell type in order of dominant was benign dyskaryotic and malignant cell.

Case Report: Arthroscopic Management of Elbow Ganglion, 8-year Follow-up.

Clara WY Wong,PC Ho,LK Hung 대한견주관절의학회 2014 대한견주관절학회 학술대회논문집 Vol.2014 No.3

중독 임신중독증에 병발한 무뇨증 1치험예

정원영(WY Chung),이교웅(KW Lee),권순욱(SW Kwon) 대한산부인과학회 1964 Obstetrics & Gynecology Science Vol.7 No.8

1. 중독임신중독증으로 인하여 초래된 급성신기능부전의 일례를 경험한 바 있어 보고하였다. 2. 입원후 첫 2-3일 간의 수분공급은 600+배설량의 원칙에 비하여 다소 과량을 공급함으로 인하여 조기에 폐수종을 초래하게 된 동기가 된 것으로 생각된다. 3. 환자는 7일째 tracheotomy를 시행한 후 극적인 호전을 보며 congestive heart failure의 위기를 모면하였다. 4. Rheomacrodex 투여로 신장순환을 촉진시키고 만족스러운 이뇨작용을 얻을 수 있었다. 5. 발병 6개월 후에는 신장기능의 완전 회복을 확인하였다. ... 자간증... 임신성고혈압.... The Case reported was 36 years old women who had eclampsia on delivery and developed acute renal failure. Therapy initially is directed toward the Control of water balance. The patient was tried to maintain on 600 cc of water plus the measured fluid loss. Tracheotomy was performed because patient was unable to expectorate her coughing sputum on 5 th date of admission. Hyperkalemia accompamy critical event. During diuretic phase, patient was replaced the adequate amount of sodium, potassium and water. Repeated blood and uriuary biochemistry returued normal level on 27th of postpartum date but low urine specific gravity which was restored completely on 5 months later.

뇨루의 임상적 관찰

정원영(WY Chung),권순옥(SU Kwon) 대한산부인과학회 1964 Obstetrics & Gynecology Science Vol.7 No.2

1. 56예의 요루에 대한 임상적관찰소견을 보고하며 원인별로는 난산으로 인한 요루발생수가 가장 많았다. 2. 수반된 제여건과 수술전처치와 예후에 관하여서 문헌적고찰과 경험을 기술하였다. 3. 수술의 방법에 있어서 여러가지 방법을 소개검토하였으며, 특히 Sims 방법과 Collins 방법을 가장 많이 시행하여 좋은 성적(제2표)을 얻었으나 suprapubic approach 는 만족할만한 결과를 얻지 못하였다. 4. 36예의 환자중 28예에서 1회수술을 하여 19예에서 성공하였으며 7예에서 2회의 수술을 하여 4예에서 성공하였으며 1예에 있어서는 4회 수술을 시도하였으나 실패하였다(제14표). 5. 수술후 감량으로 인한 합병증은 13예에서 볼 수 있었으며 뇨배양검사에서 E. Coli의 감량이 가장 많았다. 1예는 폐기전으로 수술후 18일에 급사하였으며 이는 부검으로 확인되었다. 4예에서 urinary incontinence 가 속발하였으나 이는 괄약근의 손상이 기능적으로 치유되지 못했기 때문이었다. 6. 수술의 실패에 대하여 검토해본 결과 제15표와 같은 결과를 얻었으나 특히 catheter 폐쇄로 인한 요루의 재발은 술후처치를 주의깊게 함으로서 피할 수 있는 점으로 사료된다. Our study represents the review of the case histories of 36 patients admitted to or discharged from National Medical Center with diagnosis of urinary fistula, from January 1959 through end of 1963. The causes of these fistulas were analysed and methods of management were reviewed. Particular attention was paid to those patients in whom surgical repair of the fistula was carried out and an attempt was made to evaluate the factors responsible for success of repair. Of 56 cases of urinary fistulas studied, 26 were the result of obstetric dystocia and 16 were associated with abdominal operations including Wertheim`s operation and in the remainder of the cases the lesion were related to chemical cauterization for treatment of prolapse of uterus and TB. These cases were compared with Dr. Ruseel`s 74 cases, which besides ordinary obstetrical fisseries tulas also included urinary fistula due to radium therapy and vaginal operations, where as in our no such cases were seen. Six of the fistulas healed spomaneously. One was an obstetrical fistula while others five were fistula which occured as the result of radical operation for cervical cancer. In 36 patients operative procedure were carried out on 45 occasions. These operations were mostly designed to close the fistulous opening by the vaginal approach but in 15 cases abdominal approach was used. In 20 cases of large fistulas the ureteral orifices were found either at the edge of the fistula or near to it. In most of those cases extensive scar formation with poor circulation was found. Of these 20 cases eight were discharged as inoperable, five were operated by interposition of uterus or Martius operation in combination with layer to layer closure after insertion of ureter catheter. In the remaining 7 cases the fistulas were so large and fibrosis were so extensive that it was impossible to make sufficient mobilization of the surrounding tissue to make suture without tension. Operation was carried out in 86 cases, complete cure were 21, in complete cure in 4 cases where urinary incontinence followed after the operation despite closure of fistula, failure in 11 cases. Certain general principles for management of vesicovaginal fistula were described. 1) Complete urologic study and diagnosis. 2) Elimination of infection before and after operation. 3) Optimal time of operation about 6 months after fistula developed. 4) For good operative result it is very important to make good exposure of vaginal tract, to make complete excision of scar tissue, to make sufficient mobilization and suture always to apply sutures in healthey tissue without tension. 5) Continuous, effective postoperative bladder drainage for days should be carried out to allow solid healing of bladder wound.

Evaluation of different bioimpedance methods for assessing body composition in Asian non-dialysis chronic kidney disease patients

( Sean Wy Lee ),( Clara Lee Ying Ngoh ),( Horng Ruey Chua ),( Sabrina Haroon ),( Weng Kin Wong ),( Evan Jc Lee ),( Titus Wl Lau ),( Sunil Sethi ),( Boon Wee Teo ) 대한신장학회 2019 Kidney Research and Clinical Practice Vol.38 No.1

Background: Chronic kidney disease (CKD) is associated with fluid retention, which increases total body water (TBW) and leads to changes in intracellular water (ICW) and extracellular water (ECW). This complicates accurate assessments of body composition. Analysis of bioelectrical impedance may improve the accuracy of evaluation in CKD patients and multiple machines and technologies are available. We compared body composition by bioimpedance spectroscopy (BIS) against multi-frequency bioimpedance analysis (BIA) in a multi-ethnic Asian population of stable, non-dialysis CKD patients. Methods: We recruited 98 stable CKD patients comprising 54.1% men and 70.4% Chinese, 9.2% Malay, 13.3% Indian, and 8.2% other ethnicities. Stability was defined as no variation in serum creatinine > 20% over three months. Patients underwent BIS analyses using a Fresenius body composition monitor, while BIA analyses employed a Bodystat Quadscan 4000. Results: Mean TBW values by BIS and BIA were 33.6 ± 7.2 L and 38.3 ± 7.4 L; mean ECW values were 15.8 ± 3.2 L and 16.9 ± 2.7 L; and mean ICW values were 17.9 ± 4.3 L and 21.0 ± 4.9 L, respectively. Mean differences for TBW were 4.6 ± 1.9 L (P < 0.001), for ECW they were 1.2 ± 0.5 L (P < 0.001), and for ICW they were 3.2 ±1.8 L (P < 0.001). BIA and BIS measurements were highly correlated: TBW r = 0.970, ECW r = 0.994, and ICW r = 0.926. Compared with BIA, BIS assessments of fluid overload appeared to be more associated with biochemical and clinical indicators. Conclusion: Although both BIA and BIS can be used for body water assessment, clinicians should be aware of biases that exist between bioimpedance techniques. The values of body water assessments in our study were higher in BIA than in BIS. Ethnicity, sex, body mass index, and estimated glomerular filtration rate were associated with these biases.