무엇이 MMORPG 유저들을 붙드는가?

윤성현,Yun, Seong-Hyeon 한국데이터베이스진흥원 2006 디지털콘텐츠 Vol.10 No.-

다른 게임 장르에 비해 RPG란 장르는 상대적으로 유저의 평균체류시간이 길다. 이는 RPG의 특성상 FPS나 RTS장르처럼 단판 위주의 게이미 아니라 광활한맵을 이동하면서 사냥과 퀘스트가 끊임없이 반복되기 때문이다. 그러나 같은 RPG라 할지라도 게임마다 특성이 다르기 때문에 평균체류시간은 다르게 나타나고 있다.현재까지 게임마다 평균체류시간이 다르게 나타난다는 것은 잘 알려진 사실이다. 그러나 이에 대한 원인분석이나 체계적인 연구가 부족했던 것 또한 사실. 이는 RPG장르 내 어떤 요인들이 평균체류시간에 영향을 미치는가에 대한 실증분석이 전무한 상태에서 막연한 '감' 에 의한 평가가 대부분이었기 때문이다. 여기서는 지난 5월 30일을 기준으로 게임트릭스에 등록된 86개의 MMORPG중에서 이미 서비스가 종료됐거나 과거 1년 동안 갑작스럼 패치, 업그레이드등으로 데이터 손실이 많았던 게임, 그리고 데이터를 구할 수 없었던 게임들을 제외한 총 51개의 MMORPG를 대상으로 평균체류시간을 분석했다.

GNSS 망조정에 종속기선이 미치는 영향

윤성현(Seong-Hyeon Yun),이흥규(Hungkyu Lee),박종경(Jong-Kyung Park) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.4

본 논문에서는 GNSS 단일기선해석과 망조정을 통한 측량기준점 성과 산정에서 종속기선 포함여부가 미치는 영향을 분석하기 위해 망조정 이론을 바탕으로 실험적인 연구를 수행하였다. 이를 위해 국토지리정보원 운영 위성기준점 50 개소의 관측데이터를 이용하여 종속기선 포함여부에 따라 3가지 형태의 기준점 측량망 구성 및 조정실험을 수행하고, 그 결과를 정확도 표현과 산정성과의 차이 측면에서 분석 하였다. GNSS 망조정에 종속기선을 포함하는 경우 조정성과 차이는 밀리미터 수준으로 매우 제한적이었으나, 망의 자유도와 기하강도 왜곡으로 그 정확도가 과대평가되는 결과를 얻었다. 3가지 경우에 대한 조정성과를 국토지리정보원 고시좌표와 비교했으며, 그 결과 독립기선으로만 이루어진 망의 성과가 가장 높은 일치성을 보였다. 그러나 종속기선을 포함한 조정결과는 상대적으로 큰 차이를 나타내어 성과의 정확도 표현에 왜곡이 있음을 확인할 수 있었다. 이와 같은 분석결과에 따라 GNSS 단일기선해석으로 얻어진 기선벡터의 망조정에서는 기존 성과와의 일치성, 현실적인 정확도 표현 그리고 과대한 데이터 처리에 따른 시간 및 비용 부담을 고려할 때 종속기선을 제외하는 것이 타당할 것으로 판단된다. This study examined the impact of trivial baselines obtained from GNSS single-baseline processing into a network adjustment in terms of accuracy and estimated coordinates sets. To this end, depending on the inclusion of the dependent baselines, three different types of experimental GNSS networks were composed and adjusted. The results showed that the networks including the trivial baselines are generally overestimated, but differences in the derived coordinates are limited at the millimeter level. A comparison of the adjusted coordinates with those published by the national geodetic agency showed that results of the network consisting of only the independent baselines are more constant than those of the networks with trivial baselines. Finally, a trivial baseline should be excluded from the GNSS network adjustment with a consideration of the realistic accuracy presentation and data processing burden.

다중 GNSS 표준절대측위 성능 분석에 관한 연구

윤성현(Yun, Seong Hyeon),이흥규(Lee, Hung Kyu) 한국측량학회 2019 한국측량학회 학술대회자료집 Vol.2019 No.4

GPS 측량의 종속기선에 관련한 실험적 연구

윤성현(Yun, Seong Hyeon),이흥규(Lee, Hung Kyu),박종경(Park, Jong Kyung) 한국측량학회 2018 한국측량학회 학술대회자료집 Vol.2018 No.4

공간정보의 측지기준체계 변환 방법 연구

윤성현(Yun, Seong Hyeon),이흥규(Lee, Hung Kyu),파와르 코말 나라얀(Pawar, Komal Narayan) 한국측량학회 2020 한국측량학회 학술대회자료집 Vol.2020 No.7

위암의 근치적 절제 후 발생한 뇌 전이

김용일,이준호,윤성현,노성훈,민진식,Kim, Yong-Il,Lee, Jun-Ho,Yun, Seong-Hyeon,Noh, Sung-Hoon,Min, Jin-Sik 대한위암학회 2001 대한위암학회지 Vol.1 No.2

Purpose: The common features of brain metastases from gastric cancer are unknown because brain metastasis is an uncommon pattern of metastasis. The purpose of this study was to investigate the clinical features of and the prognosis for patients with brain metastases after a curative resection for gastric cancer. Materials and Methods: Twenty-one (21) cases of patients with brain metastases of gastric cancer, who had been treated at the Department of Surgery, Yonsei University College of Medicine, were assessed retrospectively. Results: The mean age was $55.8\pm9.6$ years (range: $34\~70$ years), and the male-to-female ratio was 2.5 : .1. The most common neurologic symptom was headache ($38.5\%$), and no patient was free from the neurologic symptoms. The incidence of parenchymal metastasis (PM: $76.2\%$) was higher than that of leptomeningeal metastasis (LM: $19.0\%$). Patients with gastric cancer and brain metastasis showed high rates of blood and lymphatic vessel invasion (lymphatic vessel invasion: $85.7\%$; blood vessel invasion: $80.9\%$). According to Lauren's classification, the incidence of intestinal types was 14/21 ($66.7\%$), that of diffuse types was 3/21 ($14.3\%$) and that of mixed types was 4/21 ($19.0\%$). The mean interval between the gastrectomy and the diagnosis of brain metastasis was $24.7\pm4.0$ months (PM: 26.8 months; LM: 20.3 months). The median period of survival after diagnosis of brain metastasis was 2 months for paren chymal metastasis and 0 months for leptomeningeal metastasis. Conclusion:.. During a follow-up period, patients with neurologic symptoms should be suspected of having brain metastasis. Early diagnosis and treatment is the only hope to prolong survival in such patients.

저위전방절제술에서 문합부 누출률을 줄이기 위한 피브린글루 사용의 효용성

성기완(Gi Wan Seong),조용범(Yong Beom Cho),윤정아(Jung-A Yun),박윤아(Yoon Ah Park),윤성현(Seong Hyeon Yun),김희철(Hee Cheol Kim),이우용(Woo Yong Lee),전호경(Ho-Kyung Chun) 대한종양외과학회 2014 Korean Journal of Clinical Oncology Vol.10 No.1

Purpose: Anastomotic leakage (AL) is a major complication occurring after low anterior resection (LAR). Several methods for anastomotic protection have been tried. However, the effectiveness of these methods at preventing AL is questioned. The present study examined whether direct application of fibrin glue to an anastomotic site could be an effective method for reducing aspects of AL, such as leakage rate. Methods: This study targeted patients who had undergone LAR between March and September 2012 for primary rectal cancer or rectosigmoid cancer which curative resection was possible. Anastomosis was performed with end to end anastomosis in all patients. Fibrin glue was used in 99 patients and conventional methods in the controls (130 patients). The research was conducted as a prospective non-randomized study. Results: AL occurred in seven cases (7.1%) in the fibrin glue group and seven cases (5.4%) in the control group; this difference wasn’t statistically significant. No significant differences were found between the two groups in terms of clinical stage of primary cancer, operation time, and length of hospital stay after surgery or in the severity of leakage or the treatment policy decisions for patients with AL. An analysis of risk factors showed that the occurrence of AL was significantly higher in male patients. Conclusion: Fibrin glue applied to an anastomotic site to prevent AL during LAR did not reduce the rate of AL. No differences were noted in other aspects of AL that would favor the use of fibrin glue over conventional methods.

갈색세포종의 외과적 치료에서 복강경수술과 전통적인 개복수술 간의 비교 분석

신현백,임혜인,길원호,최준호,이정언,윤성현,허진석,김지수,노재형,남석진,최성호,김성주,전호경,이석구,양정현,김정한,Hyun-Baek Shin,Hye-In Lim,Won-ho Kil,Jun-Ho Choe,Jeong-Eon Lee,Seong-Hyeon Yun,Jin-Seok Heo,Jee-Soo Kim,Jae-Hyung Noh,Seok-Jin Nam,Seong 대한갑상선-내분비외과학회 2008 The Koreran journal of Endocrine Surgery Vol.8 No.2

<B>Purpose:</B> This study comparedthe effectiveness and safety of laparoscopic adrenalectomy with conventional open adrenalectomy for the treatment of pheochromocytoma. <B>Methods:</B> Medical records of 100 patients who underwent surgical removal of pheochromocytoma (open adrenalectomy, n=59; laparoscopic adrenalectomy, n=39) at Samsung Medical Center from June 1995 to August 2007 were retrospectively reviewed. <B>Results:</B> To draw an appropriate comparison, patients with a tumor less than 7 cm in size were evaluated (open adrenalectomy, n=23; laparoscopic adrenalectomy n=31). No statistically significant differences were evident according to age, gender and tumor size. The mean operating time was 158 min for the open surgery group and 114 minfor the laparoscopic group (P<0.01). The mean postoperative hospital stay was 10.4 days following open surgery and 5.6 days following laparoscopic surgery (P<0.01). The mean volume of the estimated blood loss for the laparoscopic surgery group (482 ml) was less than for the open surgery group (mean 229 ml) (P=0.06), and the time to first oral intake was 1.7 days after laparoscopic adrenalectomy and 3.5 days after open surgery (P<0.01). The frequency of using analgesics for postoperative pain after laparoscopic adrenalectomy was markedly lower than following conventional open adrenalectomy. There was no recurrence or complications during the follow-up periods (mean: 30 mon</B>ths). <B>Conclusion:</B> Laparoscopic adrenalectomy offers advantages of less postoperative pain, shorter operative time and a shorter hospital stay as compared with conventional open adrenalectomy. Laparoscopic adrenalectomy for treating pheochromocytoma is a minimally invasive alternative to conventional open adrenalectomy. <B>(Ko</B><B>rean J En</B><B>do</B><B>crine Surg 2008;8:106-111)</B>

예방적 회장루 복원술과 치료적 회장루 복원술의 합병증 발생비교

이동현(Dong-hyoun Lee),윤정아(Jung-a Yun),정경욱(Kyung Uk Jung),조용범(Yong Beom Cho),윤성현(Seong Hyeon Yun),김희철(Hee Cheol Kim),전호경(Ho-kyung Chun),이우용(Woo-Yong Lee) 대한종양외과학회 2012 Korean Journal of Clinical Oncology Vol.8 No.1

목적 : 본 연구는 예방적 장루와 치료적 장루 복원 수술의 합병증과 임상경과의 차이를 알아보고자 시행되었다. 대상과 방법 : 2006년 1월부터 2010년 12월까지 ○○병원 외과에서 결장직장암으로 근치적 수술과 회장루 조성술 후 장루 복원술을 시행 받은 19세 이상 373명을 대상으로 하였다. 이 중 예방적 회장루를 조성한 280명과 치료적 회장루를 조성한 93명의 장루복원 후 합병증과 임상경과를 비교 분석하였다. 결과 : 예방적 장루군과 치료적 장루군의 평균 나이는 각각 57.6세와 55.1세이었고 장루 조성 후 복원까지의 평균 기간은 각각 199.4일, 276.7일이었다. 예방적 장루군에서 27명(9.6%), 치료적 장루군에서 31명(35.4%)에서 합병증이 발생하였으며(p<0.01) 수술 후 평균 재원기간은 예방적 장루군이 6.9일, 치료적 장루군이 9.7일이었다(p<0.01). 장루 복원 후 합병증 발생에 영향을 끼치는 인자는 일변량 및 다변량 로지스틱 회귀분석에서 치료적 회장루 조성 후 장루 복원을 한 경우(p<0.01)로 나타났다. 결론 : 결장직장암수술에서 예방적 장루 복원술을 시행한 경우가 치료적 장루 복원술을 시행한 경우보다 회복기간 및 합병증 발생 측면에서 더 우월한 결과를 보였다. 따라서 문합이 불안하거나 낮을 경우 장루 조성 후 환자들의 불편함과 문합부 누출에 따른 재수술 및 장루 복원 후 합병증 증가를 고려하여 예방적 장루 조성의 실시 여부를 고려해야 할 것으로 생각된다. Backgrounds : The purpose of this study is to compare the complications after ileostomy take down between preventive and therapeutic ileostomy formation . Methods : From January 2006 through December 2010, 373 patients underwent closure of ileostomy. Inclusion criteria are as follows: 1) Patients undergoing an elective takedown of a temporary ileostomy in colorectal cancer; 2) age > 19. Excluded were patients with nonelective stoma take down and patients undertaken to treat anastomosis site stricture or anal stricture. 373 patients are included in the analysis: 280 Protective and 93 therapeutic. Results : The morbidity rate of protective ileostomy take down is 22.1% and therapeutic ileostomy take down is 30.3%. Ileus is the most common complication in both groups. Those who underwent therapeutic ileostomy have longer postoperative hospital stay (6.9 days vs 9.7 days)(p<0.01), and they also need more time to eat soft blended diet compared to preventive ileostomy group (3.9 days vs 6.8 days)(p<0.05).The variables affecting to complications after ileostomy take down in MultipleLogistic Regression Analysis analysis were therapeutic ileostomy take down(p<0.01). Conclusion : In the colorectal cancer surgery, preventive ileostomy take down showed better outcomes than therapeutic ileostomy after take down. Thus, in the case whenanastomosis is unstable or low, it is important to consider inconvenience of patients, risk of re-surgery due to anastomosis site leakage and increase in complications after therapeutic ileostomy take down when we performing of preventive ileostomy formation.

유전성 비용종증 대장암 환자에서 발생한 4개의 동시성 다발성 대장암과 1개의 소장암

김민국(Min Kuk Kim),이원석(Won Suk Lee),박치민(Chi Min Park),윤성현(Seong Hyeon Yun),이우용(Woo Yong Lee),전호경(Ho Kyung Chun) 대한외과학회 2007 Annals of Surgical Treatment and Research(ASRT) Vol.72 No.6

The frequency of multiple synchronous carcinomas of the colon and rectum have varied in different reports from 3∼4% to more than 10% of all tumors of the large bowel. Especially, the frequency is higher in hereditary non-polyposis colorectal cancer (HNPCC) patients. There are a few reported cases of five simultaneous cancers in a patient at the same time. We report here on a case of five synchronous cancers arising from the terminal ileum and colon in a patient with a strong familial tendency for colon cancer. The patient was a 43-year-old-female who presented with intermittent abdominal pain and diarrhea for one month. Colonoscopic examination revealed four adenocarcinomas at the proximal ascending, the proximal transverse, the distal descending and the sigmoid colon; the cancer in the sigmoid colon was at 30 ㎝ above the anal verge. During the operation, another 3 ㎝ sized ulcerative lesion was noted at the terminal ileum. Total colectomy, including the lesion of the terminal ileum, and ileorectal anastomosis were performed. Histologic evaluation revealed that all those lesions were adenocarcinomas invading the pericolic fat and three out of 126 lymph nodes were invaded by the cancer cells. It was a MSI-high cancer; 5 markers of MSI (BAT25, BAT26, D5S346, D17S250 and D2S123) were all unstable. We revealed a point mutation of the 67th base (GaT) of the 1st exon of hMLH1.