정상 청력 성인과 감각신경성 난청 환자에서 검사 방법에 따른 불쾌강도 역치의 비교

장동혁,최정호,전승연,김경미,김동현,한솔,박지혜,박가영,최효정,심현준,안용휘 대한이비인후과학회 2023 대한이비인후과학회지 두경부외과학 Vol.66 No.12

Background and Objectives There are several variations in the technique for measuringloudness discomfort levels (LDL). The aim of this study was to evaluate LDL by measuringpure tone and narrow-band noise (NBN) in adults with normal hearing and in patients withsensorineural hearing loss, and to analyze the correlation of LDL at different frequencies. Subjects and Method Normal listeners (n=41) with the pure tone average of 12 dB HL andpatients with hearing loss (n=42) with the pure tone average of 52 dB HL were studied from2021 to 2022. Pure tone audiometry and LDL test by pure tone and NBN were performed twicein all participants at 250, 500, 1 k, 2 k, 3 k, 4 k, and 8 kHz. Results The LDL test showed some inter-subject variability with the mean being 107.0±9.4d B, 106.0±11.6 dB by pure tone, and 100.1±6.8 dB, 100.4±6.7 dB by NBN (right and left ear,respectively) in the normal hearing group. There were no significant differences between LDLaverage by pure tone or NBN between two groups. Two serial tests showed high test-retest re-liability. There was no difference in LDL between the two groups at each frequency, exceptfor LDL by pure tone at 8 kHz in the left ear. High correlation of LDL was observed betweendifferent frequencies, except between 8 kHz and the other frequencies. Conclusion LDL by pure tone and NBN were consistent with or without hearing loss. Highcorrelation of LDL between different frequencies were shown except at 8 kHz. It might be suf-ficient to measure LDL once by pure tone only, including 8 kHz.

(주)태산팩 배송관리 시스템 구축

장동혁,송윤범,전종미,박지연 대한산업공학회 2020 대한산업공학회 추계학술대회논문집 Vol.2020 No.11

무선 ATM망에서 동적 변수를 이용한 비디오 데이터의 대역폭 할당방식에 대한 연구

장동혁,김승환,이선숙,권오석,Jang, Dong-Hyeok,Kim, Seung-Hwan,Lee, Sun-Sook,Kwon, Oh-Seok 한국정보처리학회 2002 정보처리학회논문지 C : 정보통신,정보보안 Vol.9 No.1

In WATM networks, in order to perform dynamic slot allocation required slots of mobile terminals are estimated based on DP (Dynamic Parameter) reflecting characteristics of traffic. In VBR (Variable Bit Rate) traffic, slot allocation is done at MT considering both time-dependent characteristics and QoS (Quality of Service) requirements. In this paper, DPs-buffer state information and buffer state change-are transmitted through in-band signaling. BS (Base Station) performs dynamic slot allocation considering traffic characteristics of each MT (Mobile Terminal), in other words, buffer state information informs the potentiality of 'buffer full state'to BS if MT buffer is over the specific threshold value and buffer state change notifies change in buffer state of incoming cells to MT. If buffer state information is equal to 'low (more than threshold)' and 'abrupt increase' it generates 'buffer full' state cell transmission delay or cell loss might occur. At this time BS should assign additional slots to MT, and then MT consumes cells in its buffer. In simulation, the proposed scheme shows better performance in cell delay and loss than EPSA (Estimation-Prorated Slot Assignment) in-band scheme. 무선 ATM망에서 동적 슬롯할당을 행하기 위해서는 이동국(MT)에서 요구되는 슬롯량은 이동국의 트래픽 특성을 반영하는 동적 변수들(DPs)에 의해 예측된다. VBR 트래픽에서 슬롯할당은 시의존성 특성 및 서비스품질(QoS) 요구를 고려하여 이동국에서 행해진다. 본 논문에서는 동적 변수들-버퍼상태 정보와 버퍼상태 변화-이 대역내 신호방식으로 전송된다. 또한, 기지국(BS)은 각 이동국의 트래픽 특성을 고려하여 동적 슬롯할당을 수행한다 다시 말해서, 이동국 버퍼가 특정한 임계값을 넘으면 버퍼상태 정보는 기지국에게 '버퍼풀 상태'의 가능성을 알리며, 버퍼상태 변화는 이동국에게 입력 셀에 대한 버퍼상태의 변화를 알려준다 만약 버퍼상태 정보가 '낮음(임계값보다 큰 경우)'과 '급상승' 상태이면 셀 전송지연과 셀 손실이 발생하는 '버퍼풀'을 가져온다. 이때 기지국은 이동국에게 부가적인 슬롯을 할당하며 이동국은 버퍼내의 셀들을 전송한다. 시뮬레이션을 통해 제안된 방식이 EPSA 대역내 신호방식보다 샌 지연과 셀 손실에 대한 성능이 우수함을 보여준다.

진동센서를 이용한 PCA 기반 설비 감시 시스템

장동혁,최서현,정재윤 대한산업공학회 2022 대한산업공학회 추계학술대회논문집 Vol.2022 No.11

사판식 피스톤형 유압펌프에서의 실린더내 압력, 맥동, 소음에 관한 실험적 연구

장동혁,이상규,박성환,권정호 사단법인 유공압건설기계학회 2009 드라이브·컨트롤 Vol.6 No.3

Noise reduction for hydraulic pump is strongly demanded in the market with its efficiency and durability. In order to meet this demand, it is necessary to reveal mechanism for noise and relationship between the important factors. In this paper, mathematical model for cylinder pressure which is primary reason of pulsation and sound noise were established, and examined its pressure profile by simulation. Also, the valve plate of three kind types are manufactured and tested for piston pressure, pressure pulsation, and sound power level based on the tentative standard which is officially recognized.

편도 절제술을 받은 성인의 편도 검체에서 동정된 방선균의 임상적 의의

장동혁,김호찬,김지선,권민수 대한이비인후과학회 부산,울산,경남 지부회 2019 임상이비인후과 Vol.30 No.2

Background and Objectives:There have been few studies about the association between actinomycetes and tonsillar diseases confined in adults. In this study, we tried to identify the frequency of actinomycetes in the specimens of adult patients who underwent tonsillectomy and compare the perioperative clinical characteristics according to the presence of actinomycetes. Materials and Methods:We retrospectively reviewed the medical records and specimens of patients over 18 years-old who underwent tonsillectomy in our institute from 2013 to 2018. The patients were classified into two groups according to the identification of actinomycetes, and subse- quently compared their preoperative characteristics such as smoking, alcohol consumption, tonsillar features, and chief complaints for tonsillectomy. And intra- and post-operative findings (e.g., tonsillolith, adhesion, post- operative bleeding, pain and wound healing status, etc.) and clinical characteristics were also evaluated. Re- sults:A total of 279 patients was analyzed, and actinomycetes were identified in 22 (7.9%) patients. Tonsillo- lith was more frequently identified intraoperatively in patients with positive actinomycetes (22.7% vs. 5.4%, p=0.011). However, there was no correlation between preoperative patient characteristics and presence of acti- nomycetes. In addition, the identification of actinomycetes was not particularly associated with the perioperative clinical courses of the patients. Conclusion:Actinomycetes in tonsil specimen from the adult patients under- went tonsillectomy was significantly associated with the presence of tonsillolith. There was no other meaning- ful correlation between perioperative patients’ characteristics and identification of actinomycetes.

위 식도역류질환 환자에서 바륨조영역류 검사의 유용성에 대한 고찰과 신 분류 안의 제시

장동혁,김대중,서정환,박영순 대한방사선사협회 2002 대한방사선사협회지 Vol.28 No.1

위 식도역류질환 환자에서 바륨조영역류검시의 유용성에 대한 고찰과 신 분류 안의 제시

장동혁,김대중,서정환,박영순,Jang Dong Hyuk,Kim Dae Jung,Seo Jung Whan,Park Young Soon 대한방사선사협회 2002 대한방사선사협회지 Vol.28 No.1

Purpose : This study presents a new classification of gastroesophageal reflux to evaluate the patients with Gastroesophageal reflux disease after barium contrast reflux exam to help making the correct diagnosis and Treatment according to the symptoms and

산업폐수처리시설의 고도처리공정 최적화

장동혁,조관형 청운대학교 건설환경연구소 2015 청운대학교 건설환경연구소 논문집 Vol.10 No.2

본 연구는 식품생산 공정에서 발생하는 고농도의 식품폐수를 1차 화학처리시설을 가압부상시설로 개선하고, 표준활성슬러지공법을 SMBR공법으로 최적화하였을 때 식품폐수의 처리효율을 조사·비교하였다. 최적화 전에 영양염류 중 T-N의 평균제거율은 85%, T-P 평균제거율은 89% 정도를 유지하던 것이, 응집침전공정의 침전조를 가압부상조로 대체하고 생물학적처리 후에 위치하고 있는 침전조를 SMBR로 대체한 후의 T-N의 평균제거율은 93%로 최적화 전보다 8% 정도 증가되었지만, T-P의 평균제거율은 처리공정 중에 투입되는 인산으로 말미암아 평균제거율이 88%로 오히려 최적화 전보다 1% 정도 낮은 제거율을 나타내었지만 처리수의 영양염류 농도를 방류수 기준치 이하로 안정하게 유지할 수 있었다. In this research, optimization of food manufacturing industrial wastewater treatment plant were proposed to develop additional removal of nutrients. The food manufacturing industrial wastewater treatment system was composed of a chemical coagulation-sedimentation tank and a two-step activated sludge system. The newly adapted wastewater treatment system was composed of an equalization basin, a chemical coagulation-sedimentation, and an air flotation and anoxic-oxic-membrane bioreactor. By using the above upgraded treatment system, the nitrogen and phosphorus removal efficiency were attained to 93 % and 88 %, respectively.

코성형술에서 귀연골 이식 후 생긴 켈로이드 1례

장동혁,김지선 대한비과학회 2021 Journal of rhinology Vol.28 No.2

When planning rhinoplasty, there are several options of grafts for augmentation, especially in relatively short and small Asian noses. Among such grafts, conchal cartilage is one of the most commonly used materials due to its histological similarity to nasal alar cartilage. Keloids and hypertrophic scars are fibroproliferative disorders that can occur after deep cutaneous injury. Since patients who wish to undergo rhinoplasty tend to have a lot of interest in cosmetic appearance, keloid formation can be serious complication to them. This case report presents an 18-year-old man who experienced keloid formation following conchal cartilage graft at 6 months after rhinoplasty. The authors introduce the case and review the considerations in prevention and treatment strategies for keloid scars after conchal cartilage harvest in Asian rhinoplasty.