CMOD - C 분산 언어를 위한 컴파일러 및 언어 커널의 구현에 관한 연구

최성준(Sung-Jun Choi),안순신(Sun-Shin An) 한국정보과학회 1988 한국정보과학회 학술발표논문집 Vol.15 No.2

분산 시스템 (distributed system)을 프로그래밍 하는 데에는 기존의 일반 언어보다 분산 시스템을 기술할 수 있는 능력을 가지는 분산 프로그래밍 언어 (distributed programming language)를 사용하는 것이 보다 본질적인 방법이다. CMOD-C는 분산 시스템을 기술하기 위하여 C 언어를 기본으로 하여 병렬 처리 (concurrent processing), 시스템의 모듈화 (modularization), 두 가지 방식의 IPC, 모니터의 기능을 첨가해 설계한 언어이다. CMOD-C 프로그램을 수행시키기 위해서는 언어의 컴파일러와 함께 언어의 특성을 실제로 실행하여 주는 언어 커널 (language kernel)이 필요하다. 언어 커널은 언어의 특성상 여러가지 기능을 기존의 운영 체제에서 바로 제공하는 것이 적당치 못하므로, 운영 체제와 프로그램 사이에 존재하여 기능을 수행하도록 한 것이다. 본 연구에서는 이 CMOD-C 언어를 위한 컴파일러와 언어 커널의 구현을 목적으로 하며, 컴파일러는 CMOD-C의 기본 언어인 C 언어 컴파일러의 수정을 통하여 이루어지며, 언어 커널은 컴파일러의 출력에서 정보를 받아 실행할 수 있도록 하였다. 본 연구는 UNIX를 운영 체제로 하는 MC68000 machine 상에서 이루어졌다.

온라인 구매에서 소매점 명성이 소매점 태도에 미치는 영향 - 지각된 위험, 웹사이트 품질의 매개효과 -

최성준 ( Sung-jun Choi ),송균석 ( Kyun-seok Song ),노진경 ( Jin-kyung Noh ) 한국생산성학회 2018 生産性論集 Vol.32 No.1

The objective of this study is to identify the attitudes of customers who are using online stores, considering the current transition of customers’ buying activity from conventional offline stores to online stores. To do this, the factors that may have an impact on customer attitudes toward an online store were selected, which included the reputation of the store, website quality and perceived risk, and then the relationship between the factors was also analyzed. To be more specific, the influence of the reputation of an online store was analyzed in terms of the customers’ attitude, website quality and perceived risk. Moreover, a mediation analysis was performed not only on the effect of website quality and perceived risk related with transaction on the online shopping stores, but also on the mediated effect of multiple mediators: the reputation of the online store-website quality-perceived risk- attitude toward the online store. A survey of 557 subjects who had a purchase experience at an online shopping store was conducted, from June to September, 2016, when people are likely to purchase a product or service with high perceived risk or with high involvement. Respondents were reminded of their purchase experiences from March, three months before the survey, until September, the end of the survey. The survey group was accustomed to using computers and mobile phones. We analyzed attitudes of the respondents who had directly purchased a product for their personal or household use. The findings of this survey are as follows. The reputation of an online store is confirmed to have a positive impact both on the customers’ attitude toward the online store and the website quality. The perceived risk has a negative effect on the attitude toward the online store, while the website quality serves to reduce the perceived risk and has a positive influence on the attitude toward the online store. However, the website quality negatively meditates the impact of the reputation of the online store on the attitude toward store. In addition, the mediating effect between website quality and perceived risk is also verified to have been negative. Based on the findings of this research, companies that want to their online stores and ultimately attain their marketing goal are advised to build the reputation of their online stores, improve their website quality and reduce the risk perceived by customers during a transaction process. This would be an effective method of building and maintaining a positive attitude among customers toward an online store. A limitation of this study is that it is focused only on online purchases, and only four variables are used for the Mediateding analysis, even though there are variables other than the reputation of the online store, website quality and perceived risk and attitude toward the store that are worth considering. Moreover, there was no comparison performed between online and offline purchases, and the customers responses based on the distinctive characteristics of online shopping stores were not analyzed. Future research should considering the following. First, a comparative study between online and offline purchases would provide more useful findings from a practical perspective. Second, more diverse variables that can affect customers’ online purchase should be utilized. Third, customers have preference for various online shopping stores, and have used different online shopping stores. Therefore, if a comparative study between these stores were performed, it would provide more useful findings, from practical and academic perspective. Lastly, customers use an online shopping store and demand different levels of service depending on the characteristics of a product or service (involvement, etc.). Therefore, the products and services that customers purchase should be also be studied in the future by subdividing their characteristics.

모자에서 발생한 Waardenburg 증후군

최성준(Sung Jun Choi),김광수(Kwang Soo Kim),유희준(Hee Joon Yu),손숙자(Sook Ja Sohn) 대한피부과학회 1986 대한피부과학회지 Vol.24 No.4

We report a case of Waardenburgs syndrome in 18-year-old male patient who has total deafness of the right ear, heterochromia irides, hypopigmented patches on the face and trunk, and disseminated lentigines on the entire body surface since birth. His 51-year-old mother also has total deafness, heterochromia irides, white foreloek, and disseminated lentigines on the entire body surface. The patient with this disorder may complain of pigmentary abnormalities, and we believe dermatologists should pay more attention to systemic signs of the congen:ital pigmentary disorders.

밀크커피색 반점의 병리조직학적 관찰

최성준(Sung Jun Choi),유희준(Hee Joon Yu),손숙자(Sook Ja Sohn) 대한피부과학회 1986 대한피부과학회지 Vol.24 No.4

We observed 17 cases of cafe au lait spots histopathplogi ally. Out of 17 cases, 9 cases were neurofibromatosis with neurofibromas, 6 cases were neurofibromatosis without neurofibroma, and 2 cases were normal healthy persons. The results were as follows. l. In all 17 cases, melanin pigment was increased in melanocytes and keratinocytes. 2. Griant pigment granules were identified only in 3 cases of neurofibromatosis with neurofibromas.

고압수소 노출 고무소재의 물성변화 연구

최성준(Sung-jun Choi),조성민(Sungmin Cho),염지웅(Jiwoong Yeom),김영규(Young-kyu Kim) 한국가스학회 2020 한국가스학회 학술대회논문집 Vol.2020 No.10

GPGPU 병렬 프로그래밍을 이용한 H.264/AVC 고속 화면내 예측 모드 결정

최성준(Sung-Jun Choi),한기훈(Ki-Hun Han),유영수(Yeong-Soo Yoo) 한국방송·미디어공학회 2011 한국방송공학회 학술발표대회 논문집 Vol.2011 No.11

GPU의 병렬성과 연산능력을 일반적인 공학적 문제 해결에 적용하는 GPGPU 컴퓨팅에 대한 연구가 최근 활발히 진행되고 있다. 비디오 압축과정에는 많은 양의 화소 데이터에 동일하게 반복되는 연산을 수행하는 알고리즘이 많이 적용되므로 GPGPU를 통한 고속 병렬 계산의 응용 분야로 매우 적합하다. H.264/AVC는 비디오를 압축하는 가장 최신의 국제표준으로 여러 제품군과 서비스에 대한 적용되어 시장에서 널리 사용되고 있다. 본 논문에서는 GPGPU의 응용 분야로 주목 받고 있는 비디오 압축 분야에 대한 적용으로 H.264/AVC의 화면내 예측 모드 결정과정에 GPGPU 병렬 프로그래밍을 적용하여 예측모드 결정 속도를 향상하는 방법을 제안한다. GPU상에서의 데이터 병렬처리를 위해 CUDA C언어를 사용하였으며, CPU상에서의 연산은 C언어를 사용하여 구현되었다. GPU상에서 프레임 전체에 대한 화면내 예측 모드를 병렬적으로 결정함으로써 이에 소요되는 시간을 줄여 줄 수 있었다. 실험결과 GPU상에서 병렬적으로 예측 모드를 결정할 때 Full-HD급 영상에서 약 2.8배 정도의 속도 향상을 확인할 수 있었다. 향후 GPGPU 병렬 프로그래밍을 화면 내 예측뿐만 아니라 반복되는 연산을 수행하는 다른 알고리즘에도 적용하여 부호화기의 계산 부담을 덜어준다면 고속 실시간 비디오 압축 부호기 개발이 더욱 용이해 질것으로 기대된다.

한공각화증의 임상 및 병리조직학적 관찰

최성준(Sung Jun Choi),유희준(Hee Joon Yu),손숙자(Sook Ja Sohn) 대한피부과학회 1986 대한피부과학회지 Vol.24 No.3

We observed clinical and histopathological findings of porokeratosis in 16 cases which comprised 2 linear types, 4 superficial disseminat:ed forms, 4 disseminated superficial actinic porokeratosis and 6 plaque types. From the observation, the following results were obtained. l. Clinical results 1) Eleven cases were men, 5 cases were women, and the sex ratio was 2. 2 to 1, age distribution was from 6 to 61 years (mean age: 34. 2years), and the distribution of age of onsets was from 2 to 52 years(mean age of onset' 23. lyears). 2) Four cases had family history of porokeratosis, but linear forms did not. 3) Nine cases had pruritus especially, all cases of DSAP and DSP except 1 case complained pruritus. 4) Tmo cases of DSAP had tendency of summer exacerbations. 2. Histopathological results 1) Cornoid lamellae were prominent in all cases of plaque types and linear types, and minimal in all cases of DSAP and DSP except 1 case. 2) Epidermis between the cornoid lamellae were normal or acanthotic in all cases except 1 case of plaque types and linear types, and were atrophic in 5 cases of 8 cases in DSAP and DSP.

복부CT에서 면적에 따른 CTDI와 유효선량 및 SNR의 비교 연구

최성준(Sung-Jun Choi),강준국(Jun-Guk Kang),김수인(Su-In Kim),김윤호(Youn-Ho Kim),이도경(Do-Gyeong Lee),정진경(Jin-Gyung Jung),조아라(Ar-A Cho),장재혁(Jae-Hyeok Jang),권대철(Dae-Cheol Kweon) 대한방사선과학회(구 대한방사선기술학회) 2015 방사선기술과학 Vol.38 No.3

복부CT에서 면적을 산출하여 CTDI (computed tomography dose index) 변화에 따른 유효선량 및 SNR (signal to noise ratio)을 비교함으로써 진단적 가치가 높은 영상을 얻는 동시에 환자가 받는 피폭 선량 감소를 목적으로 한다. 복부CT 검사 환자 60명을 400-499 cm 2 (12명), 500-599 cm2 (21명), 600-699 cm 2 (17명), 700-799 cm 2 (9명) 4그룹으로 나누었다. 복부CT 데이터를 ImageJ 프로그램을 이용하여 환자의 면적을 산출하였고, CTDI, DLP, SNR 및 유효선량을 계산하였다. 복부면적이 증가할수록 CTDI는 7.3 mGy에서 13 mGy로 증가였고, DLP는 394.4 mGy･cm 에서 732로, 유효선량에서도 5.9 mSv가 11mSv로 증가하였다. SNR은 12.7에서 15 dB을 유지하였다. 복부면적에 따른 CTDI의 평균은 8.9 mGy, DLP의 평균은 481.5 mGy･cm, 유효선량은 7.2 mSV로 산출되었다. 복부하중계수에 DLP를 곱하여 산출한 유효선량은 통계적의로 유의한 차이가 없었고 (p < .05), SNR에서는 유의한 차이가 있었다(p > .05). 복부CT 영상검사에서 영상의 질 향상을 위해서는 환자의 면적에 따른 CTDI를 고려하여 환자의 피폭선량을 감소시킬 수 있어야 한다. To obtain the best SNR (signal to noise ratio) due to changes in CTDI (computed tomography dose index) made for the purpose of setting the optimum image obtained by reducing the dose in abdominal CT. Abdominal CT scans of 59 patients a 400-499 cm 2 (n = 12), 500-599 cm 2 (n = 21), 600-699 cm 2 (n = 17), 700-799 cm 2 (n = 9) were separated by four groups and the effective dose was used in the Excel to get the area of the patient using the ImageJ program. Patients of CTDI, DLP, SNR, the effective dose were analyzed. Abdominal CT area was increased to 13 mGy in CTDI is 7.3 mGy, DLP to 732 in 394.4 mGy･cm, also effec-tive dose was 5.9 mSv increase in 11mSv. SNR is 15 dB was maintained at 12.7. CTDI according to the aver-age of the abdominal area of 8.9 mGy, the average of the DLP was 481.5 mGy･cm, the effective dose is cal-culated to be 7.2 mSV. Effective dose was calculated by multiplying the load factor of DLP in the abdomen showed no statistically significant difference of (p < .05), there was a significant difference in SNR (p > . 05). To improve image quality of abdominal CT scan image in consideration of the CTDI according to the volume of the patient it should be able to reduce the radiation exposure of the patients.

진행성 비소세포폐암에서 Navelbine , Ifosfamide , Cisplatin 복합항암화학요법

김태원(Tae Won Kim),김상희(Sang Hee Kim),최성준(Sung Jun Choi),최종수(Jong Soo Choi),김상위(Sang We Kim),최은경(Eun Kyung Choi),서철원(Cheol Won Suh),이정신(Jung Shin Lee),김우성(Woo Sung Kim),김동순(Dong Soon Kim),김원동(Won Dong Ki 대한내과학회 2001 대한내과학회지 Vol.60 No.5

N/A Background : We performed a phase 2 study to determine the activity and toxicity of Navelbine, Ifosfamide, and Cisplatin (NIP) combination in patients with stage IIIB-4 non-small cell lung cancer (NSCLC). Methods : Thirty-two chemotherapy naive patients were enrolled from 2 centers between February 1997 and December 1997. The median age was 57 years (range, 29-71) ; stage IIIB/IV 6/26; male/female 23/9. The regimen consisted of navelbine (25 mg/m2 day 1 and 5), ifosfamide (3 g/m2 day 5 with uroprotective mesna), and cisplatin (80 mg/m2 day 5) every 3 weeks. Results : Twenty-six were evaluable for response and 31 for toxicity. One patient was lost to follow up, one patient refused to continue, and 4 patients could not continue due to poor performance. Total of 120 cycles have been given, with median of 4 cycles per patient (range ; 1-6). Sixteen patients achieved partial response (response rate on an intention-to-treat basis, 50%; 95% C.I:32-68% ). Neutropenia was the most common toxicity. Grade 3-4 neutropenia was observed in 39% of courses ; thrombocytopenia 4% of courses ; anemia 14% of courses. Three patients developed febrile neutropenia; there was no treatment-related death. The median time to progression was 6.9 months and the median overall survival 8.0 months. The probability for 1-year survival was 25%.

비호지킨림프종의 임상상과 예후인자

김태원(Tae Won Kim),이정신(Jung Shin Lee),최성준(Sung Jun Choi),최종수(Jong Soo Choi),장대영(Dai Young Zang),이제환(Je Hwan Lee),김성배(Sung Jun Choi),김상위(Sang We Kim),서철원(Cheol Won Suh),이규형(Kyoo Hyung Lee),김우건(Woo Kun Ki 대한내과학회 1997 대한내과학회지 Vol.52 No.2

N/A Objectives: The advent of intense combination chemotherapy has transformed aggressive non-Hod-gkins lymphoma from a disease that was once uniformly fatal to one that is now often curable. Remission rates and survival may be improved by using intensive chemotherapy regimens. However, this more aggressive approach is inevitably associated with increased toxicity, and an accurate pretreament prognostic assessment of patients is required to guide the physician in selecting the most appropriate therapeutic regimen. Many studies have reported prognostic factors of non-Hodgkins lymphoma in western countries, but there are few reports on prognostic factors in Koreans and it is suggested that clinical characteristcs of non-Hodgkins lymphoma in Korea differ from those in western countries. The purpose of this study was to illustrate clinical characteristics, prognostic factors and treatment outcome in non-Hodgkins lymphoma in Korea. Methods: Clinical features of 151patients (age over 15years) with non-Hodgkins lymphoma registered at Asan Medical Center from March 1989 to December 1993 were retrospectively reviewed. Prognostic factors and treatment outcome were evaluated among 121previously untreated patients. Multi variate analysis of potential pretreatment prognostic factors was performed using Coxs proportional hazards model. Results: Of the 151patients evaluated, 55% had diffuse large cell type, while low-grades were encountered in less than 1% of the patients. Extranodal involvement was noted in 76% of the patients. Cental nervous system was the commonest primary extranodal site, followed by stomach. Complete remission was achieved in 73 of 121patients (60%). The median follow-up for 121patients was 24months and the actuarial overall survival was 48% at 3years and 44N at 5years with a median overall survival of 33months. At the median followup of 32months, the actuarial 5year disease-free survival rate among 73patient with complete remission was 65% and median remission duration was not reached. Presence of systemic B symptoms and advanced clinical stages were associated with a low complete remission rate. None turned out to be associated with the remission duration. The Coxs proportional hazards model identified age above 60years, presence of systemic B symptoms and elevated LDH level as significant independent poor prognostic factors influencing overall survival. Conclusion: This study reveals a low prevalence rate of the low-grades lymphoma and a higher propensity of diffuse large cell type. These results suggest that clinical characteristics of non-Hodgkins lymphoma in Korea are different from those in the western countries. Our data also show that certain pretreatment clinical factors can help in predicting survival and in planning treatment.