Korea Pathfinder Lunar Orbiter (KPLO) Operation: From Design to Initial Results

Moon-Jin Jeon,Young-Ho Cho,김은혁,Dong-Gyu Kim,Young-Joo Song,홍승범,Jonghee Bae,Jun Bang,Jo Ryeong Yim,Dae-Kwan Kim 한국우주과학회 2024 Journal of Astronomy and Space Sciences Vol.41 No.1

Korea Pathfinder Lunar Orbiter (KPLO) is South Korea’s first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft’s initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.

응급실에 내원한 환자에서 어지럼증의 원인과 임상양상의 분석

문원식,정경운,위준선,문정미,전병조,김용권,소정일,류진호,허탁,민용일 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: Recently, The number of patients who have been complaining of the vertigo or dizziness has been increasing due to rapid growth of elderly population and senile disease. The differentiation of dizzy patients is not familiar to most emergency physicians. This study was designed to differentiate true vertigo and to investigate the clinical difference among central vertigo, peripheral vertigo, and other causes of dizziness. Methods: The authors analyzed the cases of 237 dizzy patients who visited the emergency department of Chonnam University Hospital during the recent 2 years. For the base of dizziness, associated past illnesses, severity, nystagmus type, and the causes of central and peripheral vertigo. Results: Female patients were 142(59.9%) and male patients were 95(40.1%). The most common age group was the 6th decade. The origin of dizziness was classified as peripheral cause(25.3%), central cause(32.9%), and others(41.8%). As to nature of the dizziness, the rotatory sense was dominant in peripheral vertigo and the floating sense and blurred vision in central vertigo. Peripheral vertigo was triggered by position change of head and body, and central vertigo by the eye movement. Audiograms I showed that most patients with central vertigo had normal hearing, but 46.7% of thoswith peripheral vertigo had an abnormal hearing disturbance. Nystagmus was more prevalent in peripheral vertigo Conclusion: History taking and physical examination played an important role in the diagnosis of dizzy patients. An important part of the diagnosis of a dizzy patient could be to evaluate the peripheral origin, the central origin and others causes. Because central vertigo may be associated with a significant neurological pathology, spectral radiological studies, including MRI and CT, are mandatory to rule out a devastating brain lesion.

제7차 교육과정기 사회 교과서 역사 영역 서술의 비판적 검토

전혁진,이문기 경북대학교 사범대학부속 중등교육연구소 2006 중등교육연구 Vol.54 No.2

線型計劃法에 의한 推定財務諸表 作成

全瑨文 대구효성가톨릭대학교 1980 연구논문집 Vol.22 No.1

코로나 플라즈마 처리에 의한 HDPE 표면의 개질에 관한 연구

최진숙,전종탁,정봉규,이근대,문명준,이종무 釜慶大學校 2001 釜慶大學校 論文集 Vol.6 No.-

We are able to generate the stable plasma in open air and nitrogen using a corona plasma treatment system(CPTS) with a high voltage. This was applied to treat the surface of rather non-polar HDPE(High Density Polyethylene) intended for the improvement of adhesion of over-coated layers such as coatings, printing inks. The surface tension of HDPE was significantly improved by the CPTS. The characteristics of surface layer were evaluated by means of contact angle measurement, ATR-FT/IR spectroscopy, and it was found that functional groups were introduced into the surface layer of the HDPE. The use of nitrogen was increased the surface tension of the HDPE from 33.8 mJ/m^2 to 66.56 mJ/m^2, and highly effective method of HDPE surface modification could be realized.

요 검사용 스트립의 분광학적 분석을 위한 Computer Simulation

김성철,진병문,김재형,김정배,조진욱,전계록,이승진,김건우 동의대학교 기초과학연구소 1999 基礎科學硏究論文集 Vol.9 No.1

The spectroscopic properties of 9 pads in a urine strip were studied to develop a urine analysis system. From the present work, we determined the wavelength range which could accurately distinguish the degrees of 9 test items. A computer simulation was performed to distinguish the primary color reaction in the urine strips by using the reflectance of the urine strips, the iuminous intensity of light-emitting diodes, and the spectral sensitivity of photodiodes. The simulation results agree well with the experimental results obtained by using a UV-Visible spectrophotometer.

세포질내 정자주입법(ICSI)에 있어서 정자흡입 및 난자내 주입방법에 관한 연구

이택후,김항진,송건호,김대근,전상식,박윤규,서태광,전병균,류은경,이은숙,문진수,김광철 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Study on Method of Sperm Aspiration and Injection into an Oocyte in Intracytoplasmic Sperm Injection(ICSI) Immobilization of spermatozoa prior to intracytoplasmic sperm iniection(ICSI) sometimes results in crooked tail and this makes it difficult to aspirate sperm into an injection pipette tail first. Head-first sperm aspiration into an injection pipette avoid this problem due to the bigger size of the sperm head. The effect of head or tail-first sperm injection into an oocyte on fertilization cleavage, percentage of grade I embryos and development to blastocyst stage in ICSI program has been studied. A single living immobilized spermatozoa from oligoasthenozoospermic patient was injected into an oocyte head-first or tail-first according to the treatment. Eighteen hours after microinjection, oocytes ware inspected for survival and fertilization Fertilized oocytes with two pronuclei were cultured in 30μl drop of mHTF supplemented with 10% heat-inactivated follicular fluid(FF) at 37℃. On day 2. embryo transfer was performed with cleaved embryos. The remaining 2-8 cell stage embryos were co-cultured with BRL cells in mHTF + 10% FF for 72 hours and the developmental stage was observed. The data were analyzed by Analysis of Variance. A total of 164 oocytes from 36 cycles were assigned to earth treatment and ICSI was performed(88 head-first, tail-first). The rates of normal fertilization were 81.8% and 76.3% for head-first and tail-first, respectively. Of the fertilized oocytes, the percentage of cleaved embryos and the percentage of grade 1 embryo among cleaved embryos were 88.9% and 68.8%, 93.1% and 74.1% for head-first and tail-first, respectively. Of the 2-8 cell embryos cultured, 44.4%(16/36) and 50.0%(10/20) for head first and tail first, respectively developed to blastocyst stage. There were no differences in fertilization, cleavage, rates of grade 1 embryos, and development to blastocyst stage. In conclusion, head-first or tail-first sperm injection into an oocyte in ICSI program does not affect fertilization and subsequent embryo development to blastocyst stage in vitro.

성균관대학교 멀티미디어 원격교육 시스템(배움 한마당) 개발에 관한 연구

김석수,권해문,이상권,김상진,전진호,황대준 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1

We propose SKKU Multimedia Distance Education System for distance education between nature science campus(Suwon) and social science campus(Seoul) in Sung Kyun Kwan University on DooRae (Distributed Object Oriented Multimedia Application Crafting Environment for Collaboration) framework (or platform). We support ONE : N study mode for a group lecture and discussion between two campus, and also we support mediation for floor mode of a group lecture and brain storming for floor mode of discussion. The communication portocol of this system is composed of TCP/IP and UDP, and the network type is composed of WAN(El line)for between the Suwon campus and Seoul campus, ATM LAN for each campus(local site). And, this system supports the application development of the collaborative multimedia environment connected with the various network in the CBM (Computer based Multimedia) based. Also, it does not restrict on space between a teacher(s) and a student(s) into cyberspace which made by network. This system has an interaction, late comer, a question and an answer, multi-session, application sharing and whiteboard which resembles chalkboard. Also, various supplementary functions such as video conference and voice conference for this system are what makes face-to-face education effective. Also it supports real or non-real type. The operation system developed on windows 95.

카드뮴 측적량과 붕어(Carassius auratus) 아가미 조직 변화의 상관성에 관한 연구

배희경,김은경,남성숙,문창규,전성환,나진균,박광식 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.1

Histopathological changes and cadmium accumulations in the gills were investigated in crucian carp (Carassius auratus) exposed to 0, 0.01, 0.1, 0.5 mg/l cadmium (Cd)concentrations for 25 days. After 25 days of exposure, cadmium accumulations increased in each of the different exposure concentrations. Histopathological changes in the gills of curcian carp exposed to cadmium included the acidification of mucous cell, the terminal clubbing of lamellae, the hyperplasia of epitherial cell and the curved of secondary lamellae. The similar histopathological changes were observed once the accumulations of cadmium reached the similar levels found in the present study with the different exposure schemes. Also the acidification of mucous cell in gills appeared when cadmium accumulations reached 5 ㎍/g and more. These results suggested that histopathological changes in the gills, an appearance of mucous cell acidification, be used to estimate the relation between toxic effect and cadmium accumulations in the gills.

남성화를 보이는 여성에서 발견된 난소의 Steroid Cell Tumor 1예

조인호,정대훈,박영미,서영진,손영실,정철회,강영미,정수전,김영남,이경복,성문수,김기태 인제대학교 2006 仁濟醫學 Vol.27 No.-

Steroid cell tumor is a rare ovarian sex cord-stromal tumor which accounts for 0.1% of all ovarian tumors. Until now, only 4 cases have been reported in domestic literatures. Steroid cell tumor often secrets testosterone and presents virilization in adult women or precocious puberty in children. Treatment is often performed by surgical removal, adjuvant chemotherapy and radiation, but completely accepted treatment was not existed. We experienced a case of steroid cell tumor, which was manifested by typical virilization in a 43-year old patient, who was previously performed hysterectomy and unilateral oophorectomy. So, we present with a brief review of the literatures.