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In this paper, we present an adaptive hopping algorithm for a wireless personal area network (WPAN) receiver applying a frequency hopping. Analytical results based on the closed-form solutions for the aggregate throughput show that the proposed hopping algorithm using two denned hopping criteria is more effective method for the all kinds of interferers and gives an enhanced throughput with a moderate computational complexity.

This paper considers a channel estimation technique in a wireless personal area network (WPAN) system with complementary code keying (CCK) signaling over multipath fading channels. The performance of the proposed coherent detector is compared with that of a noncoherent detector, and a significant improvement of performance is observed in terms of the bit error probability.

We present a coarse frequency-offset synchronization technique for an OFDM-based transmission system with an emphasis on the Eureka-147 DAB receiver. The proposed frequency-offset synchronization algorithm using two defined correlation functions is shown to have high robustness against a large range of symbol timing offset with a moderate implementational complexity.

This paper describes an adaptive timing synchronization scheme and DC-offset compensation technique for a short-ranged Bluetooth system. The synchronization scheme estimates the variance of the partial-band interference, which is utilized for the trigger threshold value of the inquiry scan and page scan states, while DC-offset compensation scheme is designed using the access codes which are known to each Bluetooth device. Numerical results show the proposed synchronization algorithm is robust to the partial-band noise interference and of low complexity. Also, the new DC-offset compensation method shows more reliable estimation ability of DC-offset than the existing method without extra hardware burdens.

In the present report, we describe an unusual case of an intramural gastric abscess caused by a foreign body, detected in the form of a subepithelial tumor. A 64-year-old woman was referred to our gastroenterology clinic for further evaluation of a gastric subepithelial tumor. The patient presented with a 1-month history of sustained dull epigastric pain. Esophagogastroduodenoscopy revealed an ill-demarcated, round, smooth, protruding lesion with a small central erosion on the great curvature of the proximal antrum. Endoscopic ultrasonography indicated the presence of an ovoid, heterogeneous, hypoechoic lesion with small echogenic foci located in the submucosa and muscularis propria layers. An abdominal computed tomography scan showed focal gastric wall thickening and regional lymph node enlargement. Endoscopic submucosal dissection was performed for definite diagnosis and management. Thus, we detected a toothpick and removed it using grasping forceps. The final diagnosis was an intramural gastric abscess caused by a toothpick.

Endoscopic submucosal dissection (ESD) is a widely accepted treatment for early gastric and esophageal cancer. Compared to endoscopic mucosal resection, ESD has the advantage of enabling en bloc removal of tumors regardless of their size. However, ESD can result in a large artificial ulcer, which may lead to a considerable deformity. Circumferential mucosal defects of more than three-fourths the esophageal circumference, long longitudinal mucosal defects (>30 mm), and lesions in the upper esophagus are significant risk factors for the development of post-ESD strictures of the esophagus. In the stomach, a circumferential mucosal defects more than three-fourths in extent and longitudinal mucosal defects >5 cm are risk factors of post-ESD stricture. If scheduled early, regular endoscopic balloon dilation is effective in controlling and preventing post-ESD stricture. Moreover, intralesional steroid injections or oral steroids can achieve remission of dysphagia or reduce the need for repeated endoscopic balloon dilation. However, further study is needed to improve the prevention of stricture formation.

A 61-year-old man was referred to the hospital for treatment of a laterally spreading tumor (LST) 4 cm in diameter, which was located in the sigmoid colon 24 cm from the anal verge (Fig. 1). It was decided to treat the tumor using ESD without preprocedural histologic diagnosis because the tumor was granular-type suspicious of adenoma or adenocarcinoma confined to the mucosa. ESD was performed using gastroscope (GIF-Q260; Olympus, Tokyo, Japan) with room air insufflation. Following elevation of the submucosal layer by injection of a sodium hyaluronate acid and saline mixed solution (Fig. 2A), circumferential incision and submucosal dissection were performed, using a flex knife and IT-II knife (Olympus). The tissue was dissected along the submucosal layer after incising approximately one-third of the lesion. Thirty minutes after initiating the procedure, a small perforation occurred during dissection using a flex knife (Fig. 2B). During the 10 minutes following perforation, dissection of the surrounding area was done before endoclipping because the clips could A Case of Pneumorrhachis and Pneumoscrotum Following Colon Endoscopic Submucosal Dissection

While a number of diagnostic methods have been developed, endoscopic ultrasound (EUS) still takes the most important role in the preoperative evaluation of esophageal cancer. EUS can detect lesions of all esophageal cancer and can accurately perform T staging. In a recent meta-analysis of EUS in esophageal cancer, the sensitivity and specificity of EUS on esophageal cancer were 81.6% and 99.4% in T1, 81.4% and 96.3% in T2, 91.4% and 94.4% in T3, and 92.4% and 97.4% in T4, respectively. The use of EUS can reduce unnecessary surgeries and lead to apply proper treatments to patients. The advance of endoscopic submucosal dissection have necessitated the presurgical detection of early cancer lesions without lymph node metastasis. Understanding the practical meanings of images shown by EUS is important to decide patients for whom endoscopic treatments can be effective. In early gastric cancer, EUS can accurately predict mucosal and SM1 (invasion into the submucosal layer of less than 500 µm from muscularis mucosa) lesions, which are considered as good indications for endoscopic treatments.

45세 남자가 내원 1년 전부터 시작된 구역, 구토를 동반하지 않는 식후 상복부 불편감을 주소로 1차 의료기관에서 상부위장관 내시경 검사를 시행 후, 십이지장의 내측으로 주유두부의 부종을 동반한 비 후 소견을 보여 추가적인 검사를 위해 본원으로 전원되었다. 과거력에 만성 B형간염이 있었으며 가족력에는 특이소견 없었다. 내원 당시 이학적 검사에서 복부의 압통 및 팽만, 장음 감소나 항진 등의 이상소견은 보이지 않았다. 일반혈액검사에서 백혈구 9,000/mm, 혈색소 14.5 g/dL, 혈소판 295,000/mm, 일반화학검사에서는 총단백 6.2 g/dL, 알부민 4.0 g/dL, 혈당 84 mg/dL, 혈청요소질소 12 mg/dL, 크레아티닌 1.2 mg/dL, 총콜레스테롤 178 mg/dL, AST 21 IU/L, ALT 26 IU/L, 총 빌리루빈 1.0 mg/dL, 전해질 검사에서 나트륨 143 mEq/L, 칼륨 4.1 mEq/L였다. 상부위장관 내시경검사에서 유두부의 부종 및 발적 소견과 함께 위와 십이지장에 다량의 음식물 저류를 보여서 십이지장 이하 부위의 폐쇄소견을 의심하였다. 상부위장관조영술에서는 위, 십이지장, 근위 부 공장이 확장되어 있었으며 조영제의 통과가 지체되어 있었다. 소장 은 군집되어 우측 복강 내로 모여있었으며, 대장은 좌측 복강 내에 위 치하고 있었다(Fig. 1). 복부 전산화단층촬영 검사에서 Treitz 인대는 A Case of Duodenal Obstruction Due to Intestinal Malrotation Diagnosed in Middle-aged Man

Zollinger-Ellison syndrome (ZES) is characterized by gastrinoma and resultant hypergastrinemia, which leads to recurrent peptic ulcers. Because gastrinoma is the most common pancreatic endocrine tumor seen in multiple endocrine neoplasia type I (MEN 1), the possibility of gastrinoma should be investigated carefully when patients exhibit symptoms associated with hormonal changes. Ureteral stones associated with hyperparathyroidism in the early course of MEN 1 are known to be its most common clinical manifestation; appropriate evaluation and close follow-up of patients with hypercalcemic urolithiasis can lead to an early diagnosis of gastrinoma. We report a patient with ZES associated with MEN 1, and urolithiasis as the presenting entity. A 51-year-old man visited the emergency department with recurrent epigastric pain. He had a history of calcium urinary stone 3 years ago, and 2 years later he had 2 operations for multiple jejunal ulcer perforations; these surgeries were 9 months apart. He was taking intermittent courses of antiulcer medication. Multiple peripancreatic nodular masses, a hepatic metastasis, parathyroid hyperplasia, and a pituitary microadenoma were confirmed by multimodal imaging studies. We diagnosed ZES with MEN 1 and performed sequential surgical excision of the gastrinomas and the parathyroid adenoma. The patient received octreotide injection therapy and close follow-up.

Endoscopic submucosal dissection (ESD) is a highly refined technique compared to conventional endoscopic mucosal resection. It enables complete resection of early gastric cancer (EGC) which has no possibility of lymph node metastasis. Indication for ESD of EGC generally entails early gastric cancer confined to the mucosa with well differentiated histology, though there are clinically suitable expanded criteria. As ESD requires specific skill and expertise, endoscopists need to be familiarized with basic methods and the use of special devices. The essence of the technique is to dissect the submucosal layer with direct vision and maintain the cutting plane above the underlying proper muscle layer. Although there are some differences in the detailed technical aspect, the cardinal method of ESD is now well established and standardized. Furthermore, research and development of new ESD devices that render more efficient, safe ESD are still in progress to improve the overall result of ESD on early gastric cancer.

Beaulieu et al. (2000) proposed four signal-to-noise ratio (SNR) estimators in the time domain. The authors propose SNR estimators for an M-ary phase shift keying (MPSK) modulation in the frequency domain. A discrete Fourier transform (DFT) algorithm is used for the frequency domain analysis of the received signal. The frequency spectra enable biased SNR estimation. Circular correlation is used for robust and fast SNR estimation when the frequency offset occurs at the received signal. Simulation results show that the new estimators present good performance even when a large frequency offset occurs.

A channel estimation technique with interference cancellation in a wireless personal area network system with complementary code keying signalling is described. The performance of the proposed coherent detector is compared with that of a non-coherent detector, and a significant performance improvement as a result of the self-interference cancellation feature is observed.

An adaptive hopping technique for a frequency-hopped WPAN receiver is presented. The proposed algorithm using two defined hopping criteria is more friendly towards all kinds of interferers and gives an enhanced throughput with a moderate computational complexity.

A channel estimation technique for a short-range Bluetooth system is presented. Each Bluetooth device in the connection state knows the access codes used in the ad-hoc networks, which is utilised for the channel compensation. The proposed channel estimator can be implemented without degrading the frame and spectral efficiency by using the access code specified for the Bluetooth system.

When the chest roentgenogram reveals the presence of multiple pulmonary nodules, the basic investigation includes a history, physical examination, routine hematologic and urine studies, and sputum specimens to search the etiology. We have experienced a case of endometrial sarcoma with metastasis to the lung.

showed the highest value by 7.6, and followed by that of 3,~, 1=: and over 4," branch in this order. The seed yield varied from 168 tb 289g' m~' and the average of all soybean cultivars w~s 225g m~'. The relation beiween the seed yield and th~ days'of flOwering to maturing date was high significant difference (r=0.575, p

fixation in soybean (Sallan and Scott,1987) and it may be sensitive response at V5 to R5 stagein different growth stages of soybean. Also, the floodeffect on the growth of soybean were manifested in theyellowing and abscission of leaves at the lower nodes,stunting, and reduced dry weight and seed yield (Scott

2 . The mean pod numbers of 22 soybean cultivars treated with non-EWS and EWS were 58.6 and 37.1 per plant, respectively. The number of seed of soybeans treated with EWS also decreased about 49% of that with non-EWS. The correlation coefficient was slightly higher in 20 days (r=0.459, p