Diagnostic Imaging of Congenital Meningoencephalocele in a Holstein Calf

Kwon, Kyunghun,Lee, Byungho,Choi, Sooyoung,Cho, Jongki,Lee, Youngwon,Choi, Hojung The Korean Society of Embryo Transfer 2017 한국동물생명공학회지 Vol.32 No.1

A 10-day-old, Holstein calf with facial mass of 10 cm in diameter at the forehead region referred to Veterinary Medical Teaching Hospital in Chungnam National University. The mass was soft and fluctuating swelling. It had normal skin and hair hanging forward from frontal region and was thought to contain cerebrospinal fluid. On the skull radiography, cauliflower like-irregular marginated, soft tissue opacity mass was identified craniodorsal to the frontal bone. The mass appeared as a cyst filled with anechoic fluid on ultrasonography. Soft tissue structures considered brain tissues were observed in the deep area of the mass. On the computed tomography, a large skull defect of left side frontal bone was found, and heterogeneous materials were exposed through the defect but exposure of cerebral meninges and brain tissue were not confirmative. On magnetic resonance imaging, herniated left brain parenchyma showed heterogenous T2 and T1 hyperinsensity. In the intracranium, T2 hyperinstense and T1 hypointense fluid was identified on the left side, instead of left cerebral parenchyma. Also leftward shift of right hemisphere and midline structure, including thalamus and midbrain, were observed. The definitive diagnosis was confirmed as a meningoencephalocele based on computed tomography and magnetic resonance imaging. The calf was euthanized and necropsy was performed. On necropsy, both hemisphere were developed unequally with different size. One side hemisphere was grown in the outside through 10 cm hole on the median plane.

Empirical evaluation of receiver-based TCP delay control in CDMA2000 networks

Kwon, Oh-keun,Cha, Hojung,Han, Seung-jae,Ha, Rhan John Wiley Sons, Ltd. 2007 International journal of communication systems Vol.20 No.8

<P>Wide-area broadband wireless technologies such as CDMA2000 often suffer from variable transfer rate and long latency. In particular, TCP window-based rate control causes excessive buffering at the base station because of the lower transfer rate of the wireless link than that of the wired backhaul link. This performance characteristic of TCP further increases the end-to-end delay, and additional resources are required at the base station. This paper presents a practical mechanism to control the end-to-end TCP delay for CDMA2000 networks (or other similar wireless technologies). The key idea is to reduce and stabilize RTT (round-trip time) by dynamically controlling the TCP advertised window size, based on a runtime measurement of the wireless channel condition at the mobile station. The proposed system has been implemented by modifying the Linux protocol stack. The experiment results, conducted on a commercial CDMA2000 1x network, show that the proposed scheme greatly reduces the TCP delay in non-congested networks, while not sacrificing the TCP throughput in congested networks. Copyright © 2006 John Wiley & Sons, Ltd.</P>

Diagnostic Imaging of Congenital Meningoencephalocele in a Holstein Calf

Kyunghun Kwon,Byungho Lee,Sooyoung Choi,Jongki Cho,Youngwon Lee,Hojung Choi 한국수정란이식학회 2017 한국동물생명공학회지 Vol.32 No.1

A 10-day-old, Holstein calf with facial mass of 10 cm in diameter at the forehead region referred to Veterinary Medical Teaching Hospital in Chungnam National University. The mass was soft and fluctuating swelling. It had normal skin and hair hanging forward from frontal region and was thought to contain cerebrospinal fluid.On the skull radiography, cauliflower like-irregular marginated, soft tissue opacity mass was identified craniodorsal to the frontal bone. The mass appeared as a cyst filled with anechoic fluid on ultrasonography. Soft tissue structures considered brain tissues were observed in the deep area of the mass. On the computed tomography, a large skull defect of left side frontal bone was found, and heterogeneous materials were exposed through the defect but exposure of cerebral meninges and brain tissue were not confirmative. On magnetic resonance imaging, herniated left brain parenchyma showed heterogenous T2 and T1 hyperinsensity. In the intracranium, T2 hyperinstense and T1 hypointense fluid was identified on the left side, instead of left cerebral parenchyma. Also leftward shift of right hemisphere and midline structure, including thalamus and midbrain, were observed. The definitive diagnosis was confirmed as a meningoencephalocele based on computed tomography and magnetic resonance imaging. The calf was euthanized and necropsy was performed. On necropsy, both hemisphere were developed unequally with different size. One side hemisphere was grown in the outside through 10 cm hole on the median plane.

A Study on the Performance of TDNN-Based Speech Recognizer with Network Parameters

Nam, Hojung,Kwon, Y.,Paek, Inchan,Lee, K.S.,Yang, Sung-Il The Acoustical Society of Korea 1997 韓國音響學會誌 Vol.16 No.e2

This paper proposes a isolated speech recognition method of Korean digits using a TDNN(Time Delay Neural Network) which is able to recognizc time-varying speech properties. We also make an investigation of effect on network parameter of TDNN ; hidden layers and time-delays. TDNNs in our experiments consist of 2 and 3 hidden layers and have several time-delays. From experiment result, TDNN structure which has 2 hidden-layers, gives a good result for speech recognition of Korean digits. Mis-recognition by time-delays can be improved by changing TDNN structures and mis-recognition separated from time-delays can be improved by changing input patterns.

Antiamnesic and/or Antidementic Activity of Opuntia ficus-indica var. saboten

Yubeen Kwon,Yulan Liao,Bokyung Koo,Hojung Bae,Jiabao Zhang,Eun Hye Han,Su Min Yun,Mi Kyung Lim,Sang Ho Lee,Seo Yun Jung,Jong Hoon Ryu 한국식품영양과학회 2017 한국식품영양과학회 학술대회발표집 Vol.2016 No.10

Production of High Grade Solid Fuel from Lignocellulosic Biomass by Solvent Extraction

Sukma Hidayat,Hojung Kwon,Donghyuk Chun,Jiho Yoo,Sangdo Kim,Jeonghwan Lim,Youngjoon Rhim,Sihyun Lee,Hokyung Choi 한국연소학회 2015 KOSCOSYMPOSIUM논문집 Vol.2015 No.12

PPP 모니터링에 기반한 CDMA2000 망의 무선 품질 측정

권오근(Ohkeun Kwon),차호정(Hojung Cha) 한국정보과학회 2003 한국정보과학회 학술발표논문집 Vol.30 No.1C

본 논문은 CDMA2000 1x 망에서 무선 품질을 PPP에서의 측정으로 파악하는 방법을 기술한다. 무선 연결은 높은 오류율과 지연으로 인해 유선과는 다른 특징을 가지며, CDMA2000 1x의 경우 이런 무선 특성을 극복하기 위한 재전송 특징이 나타난다. 본 논문에서는 무선 연결에서의 상위 계층 성능 개선을 위하여, 무선 상태를 파악하는 지표로서 PPP 계층에서 측정한 무선 연결에서의 패킷 전송 시간과 PPP 오류 형태를 제시한다. 실제 CDMA2000 1x망에서의 실험을 통해 제시한 측정값들이 무선 상태 변화를 반영하고 있음을 보인다.

Evaluation of Mammary Gland Calcification in Dogs; Radiography and Computed Tomography

Kim, Soochan,Kwon, Kyunghun,Choi, Hojung,Lee, Youngwon The Korean Society of Embryo Transfer 2017 한국동물생명공학회지 Vol.32 No.3

The mammary gland tumor (MGT) is the most common neoplasia in intact female dogs. Of these, 50% are malignant and metastasis to the other sites are often occurred. Therefore, it is very important for decision of treatment plan and prognosis to differentiate benign tumor from malignancies. Calcification of MGT is a very important imaging finding. The purpose of this study was to investigate the radiological and computed tomographic images of the MGT and the morphology and distribution of calcifications in the MGT using the Breast Imaging Reporting and Data System classification. A total of 42 dogs with MGT were included in this study. The dogs were divided into two groups into benign and malignant groups based upon histologic or cytologic results. The appearance of calcification in the tumor on radiographs and CT images was analyzed for the HU value of pre- and post-contrast injection, margin, surface, and shape of the tumor and the lymph node abnormalities. On radiographs, the positive predictive value of malignant and benign tumors was 72.72 and 85.71%, respectively. On CT examinations, the positive predictive value of malignant and benign tumors was the same value of 83.33%. The maximum diameter of the tumor and the presence of abnormal lymph nodes on CT images showed a strong correlation with malignancies. Therefore, it is thought that radiographs and CT provide useful information for evaluating MGT in dogs.

CDMA망에서 모바일 단말에 기반한 TCP 성능 개선

권오근(Ohkeun Kwon),차호정(Hojung Cha) 한국정보과학회 2004 한국정보과학회 학술발표논문집 Vol.31 No.1A

본 논문은 CDMA2000 1x 망에서 이동단말 측의 측정정보와 TCP 동작 수정을 통하여 TCP 윈도우 크기를 제한하고 RTT(Round Trip Time)을 일정 수준으로 안정화 시키는 방안을 제시한다. CDMA2000 1x망은 망 구성의 특성으로 인하여 큰 RTT 값을 가지면 변화가 큰 전송률을 제공한다. TCP는 이러한 CDMA2000망에서 지나치게 큰 전송 윈도우로 인하여 변동이 큰 RTT를 보이며 베이스 스테이션의 버퍼링 부하를 증가시킨다. 본 논문에서는 CDMA2000 1x망에서 사용되는 PPP프로토콜을 이용하여 무선 최대 전송률을 측정하고, TCP timestamp option을 이용하여 RTT를 측정하는 방안을 제시한다. 또한 이 측정 값을 적용하여 TCP 수신측에서 RTT와 베이스 스테이션의 버퍼링을 일정수준으로 유지시키는 방안을 제시하고, 리눅스 프로토콜 스택 수정을 통해 적용 결과를 보인다.

Evaluation of Mammary Gland Calcification in Dogs; Radiography and Computed Tomography

Soochan Kim,Kyunghun Kwon,Hojung Choi,Youngwon Lee 한국수정란이식학회 2017 한국동물생명공학회지 Vol.32 No.3

The mammary gland tumor (MGT) is the most common neoplasia in intact female dogs. Of these, 50% are malignant and metastasis to the other sites are often occurred. Therefore, it is very important for decision of treatment plan and prognosis to differentiate benign tumor from malignancies. Calcification of MGT is a very important imaging finding. The purpose of this study was to investigate the radiological and computed tomographic images of the MGT and the morphology and distribution of calcifications in the MGT using the Breast Imaging Reporting and Data System classification. A total of 42 dogs with MGT were included in this study. The dogs were divided into two groups into benign and malignant groups based upon histologic or cytologic results. The appearance of calcification in the tumor on radiographs and CT images was analyzed for the HU value of pre- and post-contrast injection, margin, surface, and shape of the tumor and the lymph node abnormalities. On radiographs, the positive predictive value of malignant and benign tumors was 72.72 and 85.71%, respectively. On CT examinations, the positive predictive value of malignant and benign tumors was the same value of 83.33%. The maximum diameter of the tumor and the presence of abnormal lymph nodes on CT images showed a strong correlation with malignancies. Therefore, it is thought that radiographs and CT provide useful information for evaluating MGT in dogs.